Equip your electronics bench- Help!!! - Page 1
Forum section: electronics / beginners

author: finom1
author_rank: Regular Contributor
timestamp: July 03, 2016, 10:34:07 am
content: Hello, I just finished watching your review of the Rigol DS1054Z Oscilloscope:https://www.youtube.com/watch?v=ETCOhzU1O5A,amazing!!! Thank you for all your videos!I am retired, old and would like to start building Cigar Box amplifiers for my kids. I have no electronics experience but back in the 1970s I worked for Westinghouse Electric building test benches and radars for fighter jets. I was a assembly mechanic and wire-man. Point to point wiring using wiring diagrams and layout diagrams. But only the test department knew what all the electrons were doing and why!!!. I am NASA certified in soldering.I watched this other video on setting up a workbench for building and repairing amps:I also found this:https://www.trueaudio.com/rta_selection_guide.htmCould I use this software to generate a signal for all my building needs. Also, what equipment is need to check & see the signal for Even & Odd Harmonics, Harmonic distortion, Wattage of the output etc... to build a hi-quality less then 150 watt amp? You are the smartest person my son and I have found on youtube. My birthday is July 15, I will be 62 and would like to start buying one piece of equipment at a time.Bless you for helping us and Happy Fourth of July!!!

author: Rerouter
author_rank: Super Contributor
timestamp: July 03, 2016, 10:49:01 am
content: More than just one of us here, but happy to help,Here is another thread on just such a desire, essentially what you desire to measure harmonic distortion is more for a FFT function or proper spectrum analyser, but others may know better ways for low frequency measurements,https://www.eevblog.com/forum/testgear/rigol-ds1054z-fft-for-audio-spectrum/And here is a video showing you most of the method,

author: danadak
author_rank: Super Contributor
timestamp: July 03, 2016, 11:18:51 am
content: Here is a freebee that you can start with, oscilloscope, spectrum analyzer, signal generator -https://www.zeitnitz.eu/scope_enNote protect your sound card inputs -http://www.daqarta.com/dw_0all.htmhttp://www.edaboard.com/thread259543.htmlRegards, Dana.

author: finom1
author_rank: Regular Contributor
timestamp: July 03, 2016, 11:33:09 am
content: Quote from: Rerouter on July 03, 2016, 10:49:01 amHi,Thank you for sharing your wisdom with me & my son. I have a couple of Hammond & Wurlitzer amps that we want to convert into Cigar Box Guitar amps!!! It looks like so much fun. Here is an example of what we would like to do:Keep the advice flowing. There must be many who understand what equipment is needed to see all the appropriate data for this type of project.Thanks again.

author: finom1
author_rank: Regular Contributor
timestamp: July 03, 2016, 11:40:22 am
content: Quote from: danadak on July 03, 2016, 11:18:51 amHi Dana,Thank you for sharing your wisdom with me & my son."Note protect your sound card inputs -", great advice. Thank you for telling us were the land mines are!!!Can this software see the , Even & Odd harmonic peaks, wattage etc... that goes along with amp building?Bless you for helping us. It's very exciting starting on our amp building quest in life. Great people sharing their knowledge here. What we learn we will share also!!!Thanks again and Happy Fourth of July!!!

author: bitslice
author_rank: Frequent Contributor
timestamp: July 03, 2016, 11:58:44 am
content: Quote from: finom1 on July 03, 2016, 10:34:07 amWell you can toss that $2500 figure in the garbage, it's not going to cost anywhere near that,especially in America where second hand HP equipment goes for pennies.

author: finom1
author_rank: Regular Contributor
timestamp: July 03, 2016, 12:34:11 pm
content: Quote from: bitslice on July 03, 2016, 11:58:44 amHello,Any advice on exactly what equipment to purchase that will meet all of our needs in building small Pre-Amps & Amplifiers?Thank you.

author: finom1
author_rank: Regular Contributor
timestamp: July 03, 2016, 01:22:48 pm
content: What does everyone think about this?:D-lab recommends how to repair tube amps best oscilloscope Iwatsu SS-5702 -Thanks for your help.

author: bitslice
author_rank: Frequent Contributor
timestamp: July 03, 2016, 01:48:31 pm
content: Quote from: finom1 on July 03, 2016, 12:34:11 pmI'm not an audio guy at all, I'm just looking at the tat that guy was demonstrating and thinking I've got much nicer stuff for maybe £400 total. But then I've been slowly picking it up for a year or so, rather than having a shopping list to get right now.This might be useful list of handy stuff.http://diyaudioprojects.com/Testeq/testeq.htmI'd maybe look for speakers used as studio monitors, you need something accurate rather than say warm sounding. The same for a test amplifier.I'd guess that a distortion meter would be useful.I'd imagine an analog signal generator produces less noise than a digital one, same for a linear PSU rather than a switched mode one, but price is a factor.Audio seems to involve a lot of component fiddling, so maybe an LCR meter.I've no list of actual kit to suggest, but personally I just look for something that was really expensive in 1990, that is now on eBay for pennies. The most I spent was maybe £140 on an almost new 100Mhz digital scope.

author: finom1
author_rank: Regular Contributor
timestamp: July 03, 2016, 01:58:45 pm
content: Thanks, great advice. It's always helpful when people include links of what has helped them get started.Thanks again for sharing!!!

author: bitslice
author_rank: Frequent Contributor
timestamp: July 03, 2016, 02:05:19 pm
content: This is pretty solid adviceIf I lived in America I'd be typing "Hewlett Packard" into ebay.com and see what I could pick up in my local area.

author: madires
author_rank: Super Contributor
timestamp: July 03, 2016, 02:15:27 pm
content: Quote from: finom1 on July 03, 2016, 01:22:48 pmIt's a nice, simple and inexpensive analog scope for beginners and simple tasks. Nothing wrong with that! A 20MHz Leader scope is also fine, or an old Hameg (easy to repair, stardard components, circuit diagrams and service manuals available for free). Pick any of those scopes for a reasonable price, but make sure it's running fine. There are tons of videos on how to use a scope and the most important thing is to remember, that the ground leads of the probes are connected to the case and ground (wall socket's earth).

author: finom1
author_rank: Regular Contributor
timestamp: July 03, 2016, 02:35:14 pm
content: Hello,Thank you for telling us what to watch out for and how to properly hookup things. There are so many wise people here but please remember we are just starting out. We need to hear all your thoughts on what to watch out for. I love hearing stories of lessons learned!!!I am visual learner, so if someone gives me an equation to show me how to solve something or to show a result, I will learn quicker and retain the information seeing a visual display of it.Thank you for sharing!!!

author: Shock
author_rank: Super Contributor
timestamp: July 03, 2016, 03:42:13 pm
content: I strongly recommend to buy as little equipment as you can because it's a misconception that you need to rush out and spend large, it won't help completing your projects and only take away funds that could be otherwise spent on assembly and parts.Typically you would upgrade your bench as you see the need, but if you have a lot of money to throw at it then by all means say so and start spending up.Do look for a couple of multimeters suitable for measuring AC/DC voltages rated for 1000V (avoid cheap Chinese when it comes to safety). You can find lots of information already here on the forums regarding brands, measuring voltage/current and biasing is easier with multiple meters. I'd budget at least $50 each for something secondhand. Your multimeter will be your most used piece of test equipment.An audio signal generator can be had for free if you use a PC or cheaply using a home made circuit. On Ebay you can find cheap Chinese kits and generators starting at about $20.Capacitance, ESR tester. Chinese on Ebay $20.Oscilloscope, anything you can get your hands on, it needs to be two channel (which most are) to easily compare input to output.Spectrum analyzer, a PC does a really good job, spectrum analyzers tend to be expensive so do not rush into this without doing proper homework on how spectrum analyzers work and importantly what you need to know when buying one.Distortion analyzer, probably software again or later after you have made some progress you can consider upgrading.Dummy loads can be expensive to make however a great "hack" is to use Utilitech 240V Universal (water heating) elements in different configurations to make 4/8/16 Ohm non reactive dummy loads. These were sold by lowes.com item #362342 for ~$9 each, see down below for a video explaining usage.Google "Dim bulb tester" (aka the poor mans Variac), this is a reactive current limiting that allows you safely test your amp during it's maiden voyage.Eventually you may want to invest in a Variac which allows you to slowly bring up amps to working voltages and also when used with transformers doubles as a handy way to get different AC voltages on the fly.Read Chapter 3: Electrical Safety from this website until you fully understand every concept discussed.http://www.allaboutcircuits.com/textbook/direct-current/Visit these 3 youtube channels and absorb some content.https://www.youtube.com/channel/UCUEo3LPGD1gWfGJQoE0i1Gg/videoshttps://www.youtube.com/user/essoterric/videoshttps://www.youtube.com/user/Stratosaurus1/videos

author: finom1
author_rank: Regular Contributor
timestamp: July 03, 2016, 04:29:59 pm
content: Quote from: danadak on July 03, 2016, 11:18:51 amHey Dana,What do you think of this software? Which one has the most features?https://www.trueaudio.com/rta_selection_guide.htmThank you.

author: rstofer
author_rank: Super Contributor
timestamp: July 03, 2016, 05:31:25 pm
content: One is totally free, why not try it first? The other has a varying cost depending on capability and may ultimately prove more useful at the high cost levels. But I would try the free version first.Actually, I wouldn't use either of them. I'm not a fan of using my expensive PCs around high voltage stuff. I might do it if I had a disposable PC and sound card but, at the moment, I don't. For a similar reason, I hesitate to recommend the Digilent Analog Discovery that is ideal for what you are doing. It has the advantage of being a test instrument, not a sound card. But it connects to the PC's USB port and that makes me nervous for high voltage projects. I do use it for 5V kinds of things and I rarely work on anything over 15 volts.There are isolation devices for USB but I have never investigated how they work and how much protection they provide.https://www.amazon.com/Isolator-5000-Dongle-Medical-Applications/dp/B00QU232UM/ref=pd_sim_267_7?ie=UTF8&dpID=31RFpMlMzGL&dpSrc=sims&preST=_AC_UL160_SR160%2C160_&psc=1&refRID=G66P22SRXJYWB4PYNW4Yhttp://store.digilentinc.com/analog-discovery-2-100msps-usb-oscilloscope-logic-analyzer-and-variable-power-supply/

author: finom1
author_rank: Regular Contributor
timestamp: July 03, 2016, 06:02:00 pm
content: Quote from: rstofer on July 03, 2016, 05:31:25 pmGood advice,I will stick to individual pieces of equipment. Could you please wright down the most valuable pieces equipment to get started that you like for the money?Wattage will never be greater then 150 watts.Thank you for sharing!!!

author: finom1
author_rank: Regular Contributor
timestamp: July 03, 2016, 06:18:54 pm
content: Quote from: Shock on July 03, 2016, 03:42:13 pmPerfectly logical sequence to follow. Thank you for sharing all those links, we are starting out and it's very exciting receiving all your information. Just fantastic. I think it's time to start a folder and print this information to be used as a bench reference.Is it recommended to have digital & analog volt meters?What device checks the total wattage & shows even and odd harmonics readings?Thanks again.

author: ez24
author_rank: Super Contributor
timestamp: July 03, 2016, 06:36:12 pm
content: QuoteIs there a budget ? If so, say 1/2 of it because people will go over your budget very fast.If no budget - then out of my leagueHere is a multimeter I just found out about but pricey. The reason is it has two scales so you can see AC ripple (hum) on DC lines.https://www.amazon.com/gp/product/B003TO5YUK/ref=ox_sc_act_title_2?ie=UTF8&psc=1&smid=ATVPDKIKX0DERBut I suppose that two cheap meters could do the same thing. Use cheap Harbor Freight meters (even if 9v) to measure current. This is what usually blows meters and fuses. I have several that I hook up in every power line.Try and get a meter that does not use 9v batterieshttps://www.eevblog.com/forum/testgear/multimeter-spreadsheet/Do not buy used analog scopes, they are heavy (shipping) take up a lot of space, and easy to lose money on. I lost money on two of them. A lot of people here like them but they also like to fix them (not easy).There are cheaper scopes than the DZ1054z (I have one of these). Search Amazon for prices and reviews.Take a look around this site for ideas (they give members a 10 % discount)http://www.tequipment.net/?gclid=COSgxKry180CFZOCfgodSx4CYgSome usually good used power supplies : Power Designs, HP But it sounds like you do not need these.Function gen (used) Wavetek Something like this maybehttp://www.ebay.com/itm/Wavetek-Function-Generator-Model-110-Sine-Square-and-Triangle-Very-Good-Cond-/371667739552?hash=item56891fa3a0:g:fkYAAOSwvg9XcZHZWavetek is very good quality (made in my home town - San Diego) and the chances what you buy will workA place to look for goodies -https://www.eevblog.com/forum/beginners/https://www.eevblog.com/forum/beginners/from-no-parts-to-decent-stockpile-best-approach/Do you really mean cigar box? I wanted to build something in one and got turned off by the bar code and health warning. Old ones on ebay are really expensive.If you buy on ebay, buy only on items people bid on. Sort on auction, then by the Most Bids firstAll my dumb buys were the ones I was the only bidder.If you do want an analog - get one from a seller who says and shows that it works (you will pay more for this service) This is the only scope I would buy on ebayhttp://www.ebay.com/itm/Tektronix-Tek-465-Oscilloscope-Another-accurate-commercial-grade-instrument-/282078756772?hash=item41ad343fa4:g:lLwAAOSwNuxXbeKEBecause the seller is in the business of selling 465s I wished I would have started with one of his 465s (one of the coolest scopes ever). I was being a cheap ass and lost a lot of money.

author: finom1
author_rank: Regular Contributor
timestamp: July 03, 2016, 06:58:41 pm
content: Quote from: ez24 on July 03, 2016, 06:36:12 pmHi, I would like to keep the budget under $1,600 so we have money for a project. Thank you for the great advice & sharing your wisdom!!! The Boss "My Wife" would say the budget is allot less, but if we start off slow with the purchases it will help us out to complete our test bench more completely with less attention. This will a great father-son experience to have. I'm getting on in life and he will have some great memories, you helping us now will be part of them.Thanks again!

author: ez24
author_rank: Super Contributor
timestamp: July 03, 2016, 07:24:25 pm
content: Nice budget. If you have a Harbor Freight near you - take you son there and let him buy stuff. They sell meters (several models), wire, gadgets (like IR meter), tools (pliers, wire cutters, etc). I would buy the most expensive soldering iron they have (probably shit) and go from there. Soldering irons will be harder to pick than a scope.And see what kind of shopping job he does. If he does good, set him on Amazon or ebay for the big stuff. See if he can pick the stuff out with you being his advisor. Let him onto this site. Let him make the decisions (with your help)

author: oldway
author_rank: Super Contributor
timestamp: July 03, 2016, 07:32:36 pm
content: You must remember what measuring equipment was used at the time.- Tubes tester.- 1KVA variac with output circuit breaker.- analog multimeter meter 20K / volt (as Avometer 8 )- low distortion low frequency generator (Wien Bridge) (as HP-200cd)- 8/15 ohm dummy load 100W- Distortion analyser (as HP 331A)- Oscilloscope 20 Mhz (one channel is enough)- Probe / 100 2000V (to measure anode waveforms)- Capacitor tester with leak function (as Heathkit condenser tester)With the exception of the tube tester, everything else is very cheap.Don't forget a 200W iron solder for chassis soldering.NB: for repair, a tube signal tracer as Heathkit IT-12 may be usefull.

author: finom1
author_rank: Regular Contributor
timestamp: July 03, 2016, 07:41:54 pm
content: Quote from: ez24 on July 03, 2016, 07:24:25 pmGreat advice, teach him how to fish!!!I have a couple of things from the old days, Weller soldering iron, Fluke 115 True RMS VM, good hand tools, the same type I used at Westinghouse in the old days. I just need to be able to see what the output of the components, tubes & finally the project looks like. Values, Watts, THD etc...Thanks for the great advice!

author: finom1
author_rank: Regular Contributor
timestamp: July 03, 2016, 07:46:02 pm
content: Quote from: oldway on July 03, 2016, 07:32:36 pmThank you for sharing. I have read allot about Heathkit products that people have used for years in restoring vintage radios & amplifiers.Thanks again!

author: ez24
author_rank: Super Contributor
timestamp: July 03, 2016, 07:59:19 pm
content: Quote from: finom1 on July 03, 2016, 07:46:02 pmGood list from oldway. I forgot about Heathkitshttp://www.ebay.com/itm/HEATHKIT-IT-11-/122028444079?hash=item1c697649af:g:7OYAAOSwNuxXcUwlIf I had the space I would probably start bidding on this - really cool

author: finom1
author_rank: Regular Contributor
timestamp: July 03, 2016, 08:01:50 pm
content: Quote from: ez24 on July 03, 2016, 07:59:19 pmNice!!!

author: Shock
author_rank: Super Contributor
timestamp: July 03, 2016, 10:48:28 pm
content: Quote from: finom1 on July 03, 2016, 06:18:54 pmI'll simplify this as best as I can.Wattage is calculated as a measurement of the output voltage going into a specific impedance, a digital multimeter is fine for this. A non reactive dummy load is ideal for this test and also working on amps in general.Analog meters are not required but useful sometimes for either loading the circuit under test or to see a visual representation of measurement fluctuations. Digital multimeters are in most cases faster to use to and visually take a reading, but it's entirely up to the individual.To measure harmonics in the frequency domain you would commonly use a spectrum analyzer. You can also use frequency selective voltmeters and other analyzers.Don't get hung up on specific's. I did a rough calculation, you can start with spending about $200 on secondhand gear and have most bases covered if you go the software route for spectrum analyzer. Or you can spend thousands on a super nice analyzers that will sit there an gather dust.Again it's easy buying test equipment, the hard work is putting them to use and learning how to build your projects when you have no experience. $1600 to convert a few hundred dollars of amp seems excessive to me.When you see the wall of test gear some people own remember they have spent a lifetime of gathering and restoring and slowly upgrading. The modern equivalent seems to be just blowing cash and having no idea of what you are buying or doing, don't fall into the latter category.

author: rstofer
author_rank: Super Contributor
timestamp: July 03, 2016, 11:28:29 pm
content: Some kind of audio signal generator. There are kits, there are plans, maybe even some on eBay. You don't need something that goes way up in frequency - 40 kHz is more than enough. Twenty kHz is probably adequate.Simpson 260 is the classic V-O-M analog meter and I have a couple. Triplet makes a similar model but I don't remember the part number. In any event, these 260's are all over eBay. I like analog meters when I want to see things change. Like the voltage of a car battery when I crank the starter. Or the voltage drop between the battery and the line input to the starter. Things where a DMM will still be converting long after the event is over. If you are buying used, look for the model with the mirrored scale - it helps eliminate parallax errors when trying to get precision results.I like analog scopes and I have a Tek 485 that I bought off eBay for a couple of hundred bucks. I've had it about 12 years and it still works well. HOWEVER... I bought a Rigol DS1054Z and it will be my most used scope primarily for the features. If I need to look at signals over 50 MHz or so, I will use the 485. Hack the thing (directions elsewhere) and get 100 MHz of bandwidth and serial decoding all in a $400 scope. More than adequate for most hobby needs. Four channels is great for those of us dealing with digital buses. Not so terribly important for audio work. Still, who knows where this hobby goes...Any DMM will probably work - I bought a couple of EEVBlog badged DMMs just to support the cause and because the branding is cool. These are fairly expensive meters but they will last a lifetime. I gave one to my grandson. I also have one of the very expensive Flukes (because I could) and a Vichy impersonation (still a very nice meter) but the EEVBlog meter is on my bench. I also bought a half dozen of the cheap Harbor Freight meters. I'm not sure what to think of them but I gave my grandson 3 of them to do a science fair project demonstrating Ohm's law. He won... Guess the judges liked knobs and readouts...http://www.eevblog.com/store/I just bought a Hakko FX880D, also for my grandson, and it looked like a really nice unit. I saw one of his projects and the soldering was excellent. Personally, I have a Hakko 936 but they are out of production.For cutters and pliers, I bought a set from Xcelite - they are pricey but they are exactly the right tools for the job. You can probably guess where they went...https://www.amazon.com/gp/product/B000IU2KRS/ref=oh_aui_detailpage_o02_s00?ie=UTF8&psc=1I think a magnifying visor is critical. I'm getting old:https://www.amazon.com/gp/product/B000BPWPRK/ref=oh_aui_detailpage_o08_s00?ie=UTF8&psc=1You may, or may not, want to increase the magnification with a lens change. The problem is that the focal length changes. I have another visor with the higher magnification but I'll let you guess where it wound up.The list could be longer but this should give you something to think about.

author: finom1
author_rank: Regular Contributor
timestamp: July 04, 2016, 12:54:39 am
content: Quote from: Shock on July 03, 2016, 10:48:28 pmYour are right, cutting the budget in half will help greatly! It helps greatly when someone is explaining what is really needed for this type of guitar audio work. It has been an real eye opener.Thanks again!

author: finom1
author_rank: Regular Contributor
timestamp: July 04, 2016, 01:05:20 am
content: Quote from: rstofer on July 03, 2016, 11:28:29 pmHello, thank you for sharing your wisdom with us. Tell your grandson to go for the Gold and don't hold back on projects, because he will be able to ask you the most important question "why" and you will able to explain it to him. Now that's a Blessing.I remember the problem about the focal length changing, the more powerful lens on my head set the closer I had to get to the work.All the best!

author: finom1
author_rank: Regular Contributor
timestamp: July 04, 2016, 02:38:05 am
content: Quote from: finom1 on July 04, 2016, 12:54:39 amI just found this about when it comes to software and spectrum analyzers:1.2.It looks like the best value for our guitar amp projects.

author: ez24
author_rank: Super Contributor
timestamp: July 04, 2016, 04:11:42 am
content: Quote from: finom1 on July 04, 2016, 02:38:05 amCan you tell us what "value" is? Please include links. Also your videos are in the wrong order - his 30th is on top and his 21st is on bottom. So viewers look at them in the wrong order.Here is what I think are the linkshttp://www.artalabs.hr/index.htmCould not find how much a license costs.And the hardware (maybe)https://www.amazon.com/Focusrite-Scarlett-Audio-Interface-Tools/dp/B01E6T56CM/ref=sr_1_sc_2?s=electronics&ie=UTF8&qid=1467603017&sr=1-2-spell&keywords=scarllet+2i2Interesting stuff, I wonder how the Rigol would stand up to this test?You can get some good Android tablets for $50 and they can be dedicated to a chore.Can I make a request. After you get your list together, start a new topic with a title something like:"My audio amp repair test equipment list - Opinions ? "(or you can re-title this one)This has been a good topic with lots of good answers. So I added a link to this in Beginners. I think the reason is you had an object in mind - guitar amps. Most people have no goal so the answers go all over the place. Keep up the good work and I hope you will make your own videos and let us know.I do not know if this has been listedhttps://www.amazon.com/-5000-Handheld-LCR-Meter-accessories/dp/B00S298KJO/ref=sr_1_cc_2?s=aps&ie=UTF8&qid=1467604331&sr=1-2-catcorr&keywords=lcr+meter+de-5000If I was to get a LCR meter this would be the one because I do not have space for a Heathkit.Caps will be a major repair item so do not go cheap on this.

author: finom1
author_rank: Regular Contributor
timestamp: July 04, 2016, 04:53:04 am
content: Quote from: ez24 on July 04, 2016, 04:11:42 amGreat advice, we will definitely follow it. When we finally settle on the main pieces of equipment we will start a new topic as you stated to cover what we learned here to cover our cigar box & other guitar low power pre-amps and higher powered amp projects.I just remembered watching this a few years back: EEVblog #137 - BK Precision 879B Handheld LCR Meter Review -Looking at the price, you found the best buy when compared to this:https://www.amazon.com/Precision-879B-Display-Handheld-Universal/dp/B004O8Z8E2/ref=sr_1_fkmr0_1?ie=UTF8&qid=1467606823&sr=8-1-fkmr0&keywords=BK+Precision+879B+4-1%2F2+digit+40%2C000+count+Dual+Display+LCZ%2FLCR+Meter+USBThank you for sharing your wisdom!!!

author: finom1
author_rank: Regular Contributor
timestamp: July 04, 2016, 06:12:56 am
content: I want to share this supplier we used for all manufacturing solutions at Westinghouse in the 1970's: EWD Solutions -http://www.testequity.com/categories/Component+Measurement/LCR+Impedance/We bought everything from this company, you will find some fun items here!!! Get the latest catalog to find the highest quality for your test bench needs.I would like to thank everyone here for helping us get a great start!!!I just realized the original EWD Solutions company was quote, "EWD Solutions is pleased to announce that effective June 1, 2014 we were acquired by TestEquity LLC", just heart breaking. There were so many specialty tools that I ordered from them. You may still find some ideas there but it's not the same company.

author: oldway
author_rank: Super Contributor
timestamp: July 04, 2016, 08:06:47 am
content: Some explanations on the list of instruments I have provided:1) why a 20K / V multimeter? because all values on the old schematics were only valid with this kind of meter.Tube circuits are high impedance and the measured value is far dependent on the internal resistance of the meter.So only use a 20K/V multimeter.2) The importance of the harmonic distortion in a guitar amplifier: if one wishes to focus exclusively on tube guitar amplifiers, it is not necessary to measure the harmonic distortion.The guitar sound is not pleasant as it is and it is even profitable that the amplifier has a high distortion to "enrich" the sound.I added a distortion meter to allow work on the Hi-Fi amplifiers too.It should also be noted that the distortion of a tube amplifier is high enough in the range of 0.3 to 5%, which does not require to make high precision measurements.Note that a distortion of about 5% or more is visible on the oscilloscope.I definitively never should use a sound card of a computer with a tube amplifier, that's looking for troubles.An unload output transformer can generate very high voltages that will blow your sound card for sure.3) Capacitor Tester:The main problem encountered with tube amplifiers, is that of capacitor that are leaking because they are subjected to high voltages and grid circuit is generally high impedance.Any leakage causes a wrong polarization and a malfunction.It is for this reason that modern RCL testers are not suitable because they test the capacitors at low voltage and are unable to measure leakage.

author: finom1
author_rank: Regular Contributor
timestamp: July 04, 2016, 12:09:17 pm
content: Quote from: oldway on July 04, 2016, 08:06:47 amHello oldway,1. Concerning item #1 above, I should buy thehttp://www.ebay.co.uk/itm/AVO-8-Mark-5-With-Leather-Case-AVO-Leads-Excellent-Condition-100-Tested-/152126200918and not ahttp://www.ebay.com/itm/Simpson-270-5-Extra-High-Accuracy-VOM-/331747041302?hash=item4d3daa2016:g:1aYAAOSwT~9Wiv6Janalog volt meter?The first meter will be a more accurate meter and will you see a movement in the needle any faster with the first meter?2. Oldway, which capacitor tester should I buy that would be the most accurate? I am buy each piece of equipment once with my son, so pick the best:http://www.ebay.com/sch/i.html?_odkw=analog+capacitor+tester&_osacat=0&_from=R40&_trksid=p2045573.m570.l1313.TR3.TRC2.A0.H0.Xvintage+capacitor+tester.TRS0&_nkw=vintage+capacitor+tester&_sacat=0Thank you for sharing your wisdom here!!!

author: nowlan
author_rank: Frequent Contributor
timestamp: July 04, 2016, 01:10:33 pm
content: Digging the magic eye on that heathkit, but will stick to my $20 esr meter.

author: finom1
author_rank: Regular Contributor
timestamp: July 04, 2016, 01:32:15 pm
content: Quote from: nowlan on July 04, 2016, 01:10:33 pmThe cool factor is very high on that on, take a look at this site:http://www.solorb.com/elect/misc/magiceye/What are the advantages and disadvantages comparing the LCR meter above and these?1.http://www.ebay.com/sch/i.html?_odkw=analog+capacitor+tester&_osacat=0&_from=R40&_trksid=p2045573.m570.l1313.TR3.TRC2.A0.H0.Xvintage+capacitor+tester.TRS0&_nkw=vintage+capacitor+tester&_sacat=02.https://www.amazon.com/-5000-Handheld-LCR-Meter-accessories/dp/B00S298KJO/ref=sr_1_9?ie=UTF8&qid=1467638570&sr=8-9&keywords=esr+meter3.https://www.amazon.com/Peak-ESR70-Atlas/dp/B005NIBEYU/ref=sr_1_12?ie=UTF8&qid=1467638570&sr=8-12&keywords=esr+meter4.http://www.ebay.com/itm/BK-Precision-879B-Dual-Display-Handheld-LCR-Meter-with-ESR-Measurement-/322153912897?hash=item4b01de9a41:g:UiAAAOSwEetV8IIO

author: rstofer
author_rank: Super Contributor
timestamp: July 04, 2016, 02:26:39 pm
content: That Simpson 270 is a fine meter. Presumably it is an upgrade over the 260. The 260s are adequate and cheaper but I wouldn't pass up the 270 if it fit in the budget.The 260 dates back to 1939 and is only slightly changed over the decades. Look for one in the movie "Apollo 13" - realistic for the era.

author: finom1
author_rank: Regular Contributor
timestamp: July 04, 2016, 03:03:39 pm
content: Quote from: rstofer on July 04, 2016, 02:26:39 pmThank you!

author: R005T3r
author_rank: Frequent Contributor
timestamp: July 04, 2016, 11:21:08 pm
content: In my opinion the best combo would be:1. combiscope. Analog scope + digital capabilities. 20/100 Mhz2. power supply: use a cheap wall power supply, voltage selectable + a regulator3. breadboard4. signal generator: Rigol, base model5. resistor kit6. capacitor kit7. thin wires. You can use rigid ethernet wires to wire up things...8. inductors kits9. dmm. Use a Uni-T one and you are fine.10. LT spice. It's free.Remember, the best tool you can get is the oscilloscope: you can read voltages, you can see signals, you can troubleshoot things, you can also test components with it... The second best tool you can get is a waveform gen: you generate signals and you are fine. The third best thing you can have is a multimeter with capacitance. When the times comes, you upgrade them and you take some interesting stuff, but as Now, your best bet is start and see what's interesting to you.Why I didn't mention a spectrum analyzer? Well you won't need it in your life unless you play with RFs...

author: oldway
author_rank: Super Contributor
timestamp: July 05, 2016, 12:15:04 am
content: Quote from: finom1 on July 04, 2016, 12:09:17 pm1) In my opinion, the best Avometer is the model 8 Mk IV, that's the one I have. (I paid it 30€)http://www.richardsradios.co.uk/avometersdata.htmlA lot of others analog 20K/V multimeters may also be choosen.Don't buy Vacuum Tube Volt Meter (VTVM), buy an old Fluke 75, it is far better.2) You don't need nothing accurate for capacitor tester.You don't need to measure ESR, it does not matter in tube circuits.But you need the availability to test capacitors for leakage.

author: finom1
author_rank: Regular Contributor
timestamp: July 05, 2016, 12:27:38 am
content: Quote from: R005T3r on July 04, 2016, 11:21:08 pmThank you for sharing your list. There are people here with allot of wisdom to share!!!Which one would you buy this oscillascope -or one from this listhttp://www.ebay.com/sch/Electrical-Test-Equipment/92074/i.html?_from=R40&_nkw=oscilloscope+analog+tested&_sop=15while keeping scope the price as close to $400 as possible?Thank you.

author: rstofer
author_rank: Super Contributor
timestamp: July 05, 2016, 12:49:28 am
content: Well, that leads up back to the analog versus digital scope debate which is endless! There is a current version of the topic running around right now.I like analog scopes but the features of the digital scope just make the scope so much more worthwhile. I don't want a scope "for parts" or "couldn't test" and, all in, I guess I would rather have a new scope with a warranty - all things being equal. If the budget can stand the DS1054Z then that's what I would do. And I did...Now, if the budget was half that amount, a new digital scope would be right out the window. In that case, I would look for a used analog scope and preferably one that is 'calibrated'. But who knows if the 'calibration' is traceable? It could as well be a joke. Nevertheless, that's where I would head. Something like:http://www.ebay.com/itm/Tektronix-2215A-60MHz-Oscilloscope-Calibrated-Tested-Two-Probes-Power-Cord-/162126488109?hash=item25bf7de22d:g:moQAAOSwwo1Xeu17I linked that particular scope because it was the first one I ran across on you linked page that was calibrated. There's nothing special about it other than it is refurbished and calibrated.I would have to add $30 for shipping.At some point, by the time you get a decent and working analog scope, you are close to the cost of the DS1054Z and that's a compelling scope. I certainly like mine!

author: finom1
author_rank: Regular Contributor
timestamp: July 05, 2016, 01:27:08 am
content: Quote from: oldway on July 05, 2016, 12:15:04 amHello Oldway,That link is so cool. There is a wealth of history there!!!Thank you for sharing your wisdom with us!!!I looked at your meter, I think it would look great on our work bench.Great advice, thanks again.

author: finom1
author_rank: Regular Contributor
timestamp: July 05, 2016, 01:33:14 am
content: Quote from: rstofer on July 05, 2016, 12:49:28 amThank you for sharing your ideas and what matters most for this type of guitar amplifier work. Keep the ideas flowing.Thanks again.

author: rstofer
author_rank: Super Contributor
timestamp: July 05, 2016, 02:30:16 am
content: Quote from: finom1 on July 05, 2016, 01:33:14 amI don't want to take credit where none is due. I know absolutely nothing about guitar amplifiers. About 60 years ago I built a Heathkit 8W tube-type amplifier and that is the extent of my time with audio.I have some equipment and I know a wee bit about electronics but that's about it.Good luck with your projects!

author: R005T3r
author_rank: Frequent Contributor
timestamp: July 05, 2016, 08:14:49 am
content: Quote from: rstofer on July 05, 2016, 12:49:28 amI've came up with a combiscope oscilloscope, because NOW his best bet is to start actually doing some projects. So, instead of bugging out with what is the best instrument or what is the best "convenient" one, the OP should tell us what he's planning to do, what are his interests in electronics (I hardly doubt that he's interested in radars anymore). Are you intended to make only guitar amplifiers and other instrument-oriented projects? If so, an oscilloscope like the DS1054Z is useless because you will never use it's full bandwidth.

author: oldway
author_rank: Super Contributor
timestamp: July 05, 2016, 08:27:40 am
content: At the time of the Beatles, I was making guitar amplifiers for a group of rock musicians.I had a very simple and basic measurement equipment because this kind of amplifiers is not demanding.It is precisely this lack of quality and performance that did, and still do, that these amplifiers have a different sound from that of modern transistors amplifiers.Wanting to make better amplifiers (distortion and bandwidth) is exactly the mistake not to do.Why use a completely outdated technology if it is to try to do the same as a 50 bucks actual amplifier "made in PRC" ?If you want to be consistent, one must use the same measuring devices as those employed at the time.There is moreover an advantage in that: the tubes measuring devices were much reliable for use with circuits where there were very high voltages (several hundred volts), whereas modern devices are not provided for such accidental overloads.Of course, you can also use updated high end measuring equipments.But that does not respect the philosophy and purpose of your project.Regarding the purchase of these old measuring equipment, you must have patience and look for bargains.You can certainly buy at very low prices or even get them for free.The more expensive item is probably the tube tester...(about 200 US§)NB: the scope I used in this time was a heathkit io-12e....NOT A RIGOL DS1054Z...What I had in this time:Sine square wave generatorhttp://www.radiomuseum.org/r/mble_bem004_bem_004.htmlMultimetershttp://www.radiomuseum.org/r/hioki_multimeter_af105.htmlhttp://www.radiomuseum.org/r/hansen_multimeter_uv_47.htmlhttp://www.radiomuseum.org/r/avo_universal_avometer_8_mk_i.htmlOscilloscopehttp://www.radiomuseum.org/r/heath_laboratory_oscilloscope_i.html

author: finom1
author_rank: Regular Contributor
timestamp: July 05, 2016, 10:02:47 am
content: Quote from: R005T3r on July 05, 2016, 08:14:49 amHello R005T3r,I want to personally thank you for sharing here. Because of your valuable input and others, we sat down and made a list of what our "projects goal" in life at this time is:1. Have a test bench that is designed & equipped specifically to completely checking all components and parameters of our projects, "Vacuum Tube Amplifiers".2. We would like to "restore & modify" vintage Tube Amplifiers for the purpose of turning them into "guitar amplifiers".3. Some examples would be:A.B.C.D.E.I hope this examples help clarify what we are expecting from our test bench equipment to do now!Any thought would be greatly appreciated.Thanks again.

author: finom1
author_rank: Regular Contributor
timestamp: July 05, 2016, 10:33:22 am
content: Quote from: oldway on July 05, 2016, 08:27:40 amHello Oldway,I only wished I lived close by you. You have been through the quest we are just starting on!!! My wife makes a killer "cheese cake" that I could bring over for you. Listening to your experiences will keep us safe and speed our way through some great projects for kids. That is our mission, to help inspire young people to have fun with electronics. To put there minds on leaning, educating them while having fun. We believe this will make better memories for them, compared to whats going on in the world today. I had fun as a kid and was always excited to find out how things worked. We would like to provide a place for kids to come over a learn at their own pace, opening their minds to the possibilities that life has to offer. We will post here a & make youtube videos as examples.Please see the response we made to R005T3r, about what our goals are for setting up a working test bench for our Guitar Amplifier Projects.I hope reading it will inspire you to again share the specifics of what type of equipment & models if possible would be best for us to achieve our goal.Oldway, we want to show respect by waiting and finding the best value in our purchases. I big problem became evident when assessing our repair skills at this time. That will mean spending more money for test equipment that is working and has been tested! I hope you understand our problem with lack of experience and knowledge at this time in life.Respectfully,finom1 & son

author: oldway
author_rank: Super Contributor
timestamp: July 05, 2016, 12:47:09 pm
content: Thank you for your kindness and sympathy.I would gladly help you, but I live in Europe, it's a bit far from the USA ....I remind you that the voltages in a guitar amplifier are very high (up to 800V) and there is a serious risk of working on these tube amplifiers.It is not recommended for a beginner, much less for a kid.If you buy your measuring instruments with care, you should not spend more than a few hundreds US§.This old tube measuring instruments are usually very simple and easy to repair.So do not be afraid to buy a faulty instrument, this will increase your experience.At worst, you get help from a friend or on this forum.I wish you great success in your projects.NB: about analog multimeters....great video as al the Dave's videos.

author: R005T3r
author_rank: Frequent Contributor
timestamp: July 05, 2016, 12:58:28 pm
content: Alright, well, this clarify a lot of things, and changes a lot tools to add in your collection, also.When you are dealing with audio, especially antique things you will need:1. tube/valve tester2. a decent soundcard + pc : it will became handy because when you actually fix things up, you can record thing up and monitor the levels. It will also give you a clear idea on what the problem may be. Also, if you are going to change the tubes and valves and stuff, you can see the difference.3. a multi meter. A decent one. You are dealing with HV and you must not be cheap, otherwise you end up killing yourself.4. a good/solid power supply: vintage always equals to more power consumption, and nasty voltages. Better be ready, since you don't know what kind of stuff you are going to test...5. an oscilloscope. a basic oscilloscope would do most of your jobs. Take a combiscope 20Mhz, it's not that much and you won't regret it.No need of digital things.6. an audio spectrum analyzer may be handy in some few situations (that's why I don't recommend it), but there's even something better for the price, see after...7. mains filter. When you are working with the audio spectrum, low (0-200 Hz) lead to mains interference, menaing you will hear hums...8. an audio signal generator. This may be very tricky to find. See after.So, whenever you are dealing with HV, you MUST not be cheap on instruments, and you can't trust a 100 usd multimeter. Better considering a good one instead, security first.As a reguard for power supply, anyway, take something at least 5A rated, I can't tell which voltages tought: never used valves, but 30/60V may be a good range... Also, take a mains isolated one.As a reguard to mains filtering: yes, you will need some kind of filtering otherwise you may add the hum problems on your device under test (or restoration)As for audio signal generators, you need something very specific, and even if the device is in specs it don't mean it sounds good... take something refurbished DC-250Khz... You won't need more, and it have to be very precise and low distortion.As a reguard for the oscilloscope, if you don't like analogs and you want digitals take a basic one, don't spend too much since it's not worth it.The most fitting solution to your needs instead of a spectrum analyzer or instruments of any kind exept your multimeter may well be an audio analyzer or a signal analyzer (better if specific for audio), like this units here:http://www.ebay.com/itm/Panasonic-VP-7723A-5Hz-100KHz-0-0005-Audio-Analyzer-/380403386509http://www.datatron.it/user/articoli.php?op=det&id=624Don't forget that if you want to spend more, there's this one:U8903A Audio Analyzer :http://www.keysight.com/en/pcx-x205218/audio-analyzers?nid=-32511.0.00&cc=IT&lc=enand it's $14.000 (that's not much, considered that a decent spectrum analyzer is well over $20K), however, this is an example. You can find a lot of old stuff that it's more suited to the technology you are dealing with...

author: Paul Price
author_rank: Super Contributor
timestamp: July 05, 2016, 02:00:24 pm
content: I don't get it. It's like everyone is set on encouraging you to build your own NASA facility to get a kid's rubber-band powered airplane tested.First of all, the cool sound is best when distorted, so why bother with clean output when the kids are going to add fuzz pedals to feed their guitar amps a distorted signal anyway.All you need to do is install a phone plug on the amps you have already working and let the kids rock out!Buy yourself a cheap 2-channel analog oscilloscope and a used multimeter at a local HamFest, flea market, or ebay and you are in business!You don't need a Distortion Analyzer, just get to know how to use an oscilloscope.With the purchase of a small solderless breadboard, one quad-opamp and a few resistors and capacitors you can easily create a high quality sinewave test signal for testing power smplifiers, total cost only a buck or two or maybe nothing (if you salvage parts from a discarded piece of home electronics equipment.)With the input signal to the amp on the first oscilloscope channel and the inverted output of the amplifier on the second channel, you can adj. the variable gain on one vertical channel to cancel out the input signal..what is left that doesn't cancel out is the distortion part of the output. It is a simple as that. You can use automotive taillight incandescent bulbs for a high-power load for testing.If you spend more than $100 to start playing around with electronics then you are just wasting money.

author: ez24
author_rank: Super Contributor
timestamp: July 05, 2016, 06:11:18 pm
content: Quote from: Paul Price on July 05, 2016, 02:00:24 pmSOP

author: finom1
author_rank: Regular Contributor
timestamp: July 05, 2016, 07:07:34 pm
content: Quote from: R005T3r on July 05, 2016, 12:58:28 pmRight on point, thank you!

author: rstofer
author_rank: Super Contributor
timestamp: July 05, 2016, 07:20:11 pm
content: Quote from: R005T3r on July 05, 2016, 08:14:49 amI can't get to the part where having excess bandwidth is a bad thing and left to itself, the 1054Z is only a 50 MHz scope. Sure, I like analog scopes and if the right one comes along, fine. Something in the $200 or less range would be great. If not, it's pretty nice to get a fully featured digital scope for $400, complete with a warranty. A scope is a forever kind of thing. Then too, there is no compelling reason to hack the thing just to get bandwidth and serial decoding if they are not going to be used. OTOH, why not? Get it while you can kind of thinking.Of all the tools on the bench, the scope is probably the most important and the most useful. It might be possible to follow the input through the amplifier with a V-O-M but it's a lot easier to do with a scope. FWIW, I would note the voltage at a test point with the V-O-M BEFORE I touched it with a scope probe. There are limits for the voltage input to scopes - even with a x10 probe. Read the datasheet for the scope!I would want the V-O-M but I could settle for a DMM even though the readings may be a bit high. I could even settle for a $6 Harbor Freight DMM if I had to. But I want a decent scope and I want to know that it works and, hopefully, will keep on working. I'd be pretty careful probing high voltages with the Harbor Freight meter! Maybe some low voltage gloves would be a good idea - low voltage being 600V and below, not 12V!I have nothing but good things to say about my $200 Tek 485 350 MHz scope. It's great and it comes from a family of scopes I have long admired. But I got lucky when I bought it through eBay. It worked and has kept on working for 12 years. I'm not sure my experience is universal! A non-functional analog scope doesn't even make a good boat anchor.

author: finom1
author_rank: Regular Contributor
timestamp: July 05, 2016, 07:50:51 pm
content: Quote from: rstofer on July 05, 2016, 07:20:11 pmThank you for make good points on safety and long term value.

author: rsjsouza
author_rank: Super Contributor
timestamp: July 05, 2016, 09:03:33 pm
content: I glanced over the thread and saw a few recommendations. I also agree that purchasing "the world" of equipment right now may not be the best idea, but several sensible options were provided. I will add a few.I saw somewhere that a variac was needed. I purchased a Mastech one that has good quality (checkhere) and I have been using it since then without a glitch.I drool over Krohn Hite oscillators for audio, but I haven't had the chance to get one yet. If you are looking for distortion measurements, look at eBay/craigslist for their 4400 series of ultra pure sinewave generators (one ishere). I wouldn't jump to it from the get go, but it is surely a good model number to keep in your pocket if you ever feel the need to perform these types of measurements.

author: deadlylover
author_rank: Frequent Contributor
timestamp: July 06, 2016, 05:09:42 am
content: I'll also echo some of the suggestions where you don't need to build the perfect electronics work bench to get started, you can do a hell of a lot with just a soldering iron and a multimeter or two (and maybe a scope =P). You don't need an LCR meter to know a bulging cap is knocking on death's door for example (and if you're restoring old gear, you'll replace all the electrolytics anyway as a rule), so get stuck into it and have multiple projects on the table to stop everything stalling when you're waiting for a new piece of gear to come in.Keep a lookout for broken equipment being sold for very cheap, even if you fail to repair them you can always salvage the parts and I think the educational value is priceless. Maybe start with pieces that have service manuals and schematics first.For a scope you could go either way, get something cheap or get a 1054Z to act as your stable/reliable base. I'm sure you'll have no problems at all offloading the 1054Z for not too much loss in the future if you decide you don't need it anymore, so that's something to keep in mind.The Panasonic audio analyser linked earlier and it's sister models might be all you'll ever need, some can measure distortion separately up to the 5th harmonic at the touch of a button. The VP-7722A I got for $300ish can measure down to -112dB (0.00023%) THD+N, @ 1khz/30khz BW 2Vrms, and I don't think you'll be making many tube amplifiers that can exceed that. To put that in perspective you need to spend 30 grand on the Audio Precision flagship to reach -120dB performance.You'll have to be very patient and somewhat brave to get one as cheap as I did, perhaps it's not for the faint of heart if you have a set budget, but these old dogs will go head to head with any entry level or midrange analyser today in terms of residual distortion anyway.

author: finom1
author_rank: Regular Contributor
timestamp: July 06, 2016, 12:06:42 pm
content: Quote from: rsjsouza on July 05, 2016, 09:03:33 pmThank you for sharing your ideas!

author: finom1
author_rank: Regular Contributor
timestamp: July 06, 2016, 12:08:57 pm
content: Quote from: deadlylover on July 06, 2016, 05:09:42 amThank you for sharing your ideas!

author: KL27x
author_rank: Super Contributor
timestamp: July 06, 2016, 07:54:16 pm
content: Buying stuff doesn't make you learn by osmosis. It is not like you're opening a shop to manufacture/test/repair X product, and want to outfit it with stuff the techs you will hire might need.You want to make cigar box amplifiers for your kids. Yourself. If you need to ask us, you might as well save your money. If you just want a good cover to show the wife you're busy, buy a power supply, DMM, scope, and a soldering iron.

author: oldway
author_rank: Super Contributor
timestamp: July 07, 2016, 07:57:09 am
content: You should first make a list of the measurements and tests you will need to do and specify what the precision level you need.Using a modern DSO on high voltage circuits as encountered in guitar tube amplifiers is not a good idea.Risk to blow up the analog front end is high.

author: finom1
author_rank: Regular Contributor
timestamp: July 07, 2016, 10:34:13 am
content: Quote from: oldway on July 07, 2016, 07:57:09 amHello oldway,I sent you a message did you get it. I asked about a choice of specific meters that I would like to buy now.Thank you.

author: finom1
author_rank: Regular Contributor
timestamp: July 08, 2016, 01:11:26 am
content: OK, made our first purchase today:Simpson 270-5RT Extra-High Accuracy Analog Multimeter -http://www.ebay.com/itm/122036060298Thank you oldway!Oscilloscope is next in line.Thanks everyone for your ideas.

author: rstofer
author_rank: Super Contributor
timestamp: July 08, 2016, 05:20:42 am
content: Quote from: finom1 on July 08, 2016, 01:11:26 amGreat choice!You might look into x100 scope probes if you want to work on tube type equipment. With a x10 probe you are only allowed to go up to 300 Vrms on the DS1054Z. A little cushion would be nice. It's easy to set the scope for 1x, 10x, 100x or even 1000x plus some other built-in values.

author: finom1
author_rank: Regular Contributor
timestamp: July 08, 2016, 11:53:41 am
content: Hello,could you please provide a link to the very best test & accessories probes to protect test scope up to 1000 volts? I will be strictly working on tube amps. I picked up two vintage radios with giant tube amps in them.Looking forward to input to keep this type of investment safe!!!Thanks

author: oldway
author_rank: Super Contributor
timestamp: July 08, 2016, 12:39:40 pm
content: Simply, do not buy an expensive oscilloscope.Stay in the range 50 to 100 US§Modern oscilloscopes are not designed to work on high voltages such as there is in guitar amplifiers. ( Rigol 10V/div, Tektronix 465 50V/div)When you have burned the front end input stage of your Rigol 1054Z, you will understand what I mean ....How will you fix it?How much the repair is going to cost you?You are a beginner, you will make mistakes, that's normal.

author: rstofer
author_rank: Super Contributor
timestamp: July 08, 2016, 01:45:29 pm
content: Quote from: finom1 on July 08, 2016, 11:53:41 amThe best probes will be Tektronix and they run about $500 EACH!https://www.amazon.com/Tektronix-P5100A-Passive-Voltage-Length/dp/B005K0M45OI would be looking for something a LOT cheaper because the frequencies involved aren't very high. All we really need is a probe with a 99 MOhm impedance instead of 9 MOhm for the x10 probe.Something like:http://www.all-spec.com/Catalog/Test-Measurement/Oscilloscopes-Accessories/Oscilloscope-Probes/5827A-19816?utm_source=bing&utm_medium=cpc&utm_campaign=Product%20Listing%20Ads%20-%20Shopping&utm_term=1100400298755&utm_content=PLAhttp://www.aliexpress.com/store/product/P4100-High-Voltage-Oscilloscope-Probe-2KV-100-1-100MHz-Alligator-Clip-Test-Probe/608349_32482963758.html

author: R005T3r
author_rank: Frequent Contributor
timestamp: July 08, 2016, 02:49:58 pm
content: Nah, just take a look at this ones:http://uk.rs-online.com/web/p/oscilloscope-probes/7296655/: they are 2000V rated and they are fine, also not that expensive.I hardly doubt these would be any good for your pourpouse:http://uk.rs-online.com/web/p/oscilloscope-probes/3669141/: they are rated 15KV. Last time I've seen one of these was at a transformer factory.

author: ez24
author_rank: Super Contributor
timestamp: July 09, 2016, 01:25:00 am
content: Quote from: rstofer on July 08, 2016, 01:45:29 pmYou might want to give Aliexpress a try. Seems to be the best place to buy electronics related stuff.Going to start a new topic about them

author: R005T3r
author_rank: Frequent Contributor
timestamp: July 09, 2016, 08:44:36 am
content: Quote from: ez24 on July 09, 2016, 01:25:00 amNO, it's not at all the best place to buy instrumentations, especially security rated probes. Man, you are working in a possibly HV envoriment. It's like having a black mamba on a stick and you wear lattex gloves. Don't do that, spend more but be safe!

author: oldway
author_rank: Super Contributor
timestamp: July 09, 2016, 05:17:59 pm
content: Look at this interesting video "restoration video" to understand how important it is to have a capacitor analyser with leakage test.https://www.eevblog.com/forum/projects/1959-gibson-gibsonette-repair/NB: he is using a capacitor checker Heathkit IT-11http://tubularelectronics.com/Heath_Manual_Collection/Heath_Manuals_IT-NE/IT-11/IT-11.pdf

author: nanofrog
author_rank: Super Contributor
timestamp: July 10, 2016, 03:01:29 am
content: Quote from: finom1 on July 08, 2016, 11:53:41 amAs mentioned, oscilloscopes aren't designed to take high voltages. You'd want to use say a 100x probe vs. a 1x or 10x. Given the bandwidth requirement isn't that demanding, you'd be able to find these relatively inexpensively as well.For example:100x 2KV High Voltage Oscilloscope Probe 100MHz. Not expensive at all.

author: finom1
author_rank: Regular Contributor
timestamp: July 10, 2016, 03:30:00 am
content: Quote from: oldway on July 09, 2016, 05:17:59 pmHello,What is better a, IT -28 or IT -11?Thank you.

author: finom1
author_rank: Regular Contributor
timestamp: July 10, 2016, 03:39:04 am
content: Please vote for the scope you would buy first for working on tube guitar amps:1 Hameg HM 605or2. HP1740ADo both scopes have component capability testing built in?Thank you!

author: ez24
author_rank: Super Contributor
timestamp: July 10, 2016, 03:54:50 am
content: Quote from: finom1 on July 10, 2016, 03:39:04 amBoth are a gamble - if you have a trace you may have dirty switches. As a gamble you may or may not get a good scope. If you get a bad one - consider it as a waste of money.Both of my used analog scopes had dirty switches PIAThere are a lot of analog pieces of shit out there. (that is why people sell them as "unable to test")Buying used scopes is a bad idea in my experience. Unless you can test them out before you buy them (maybe on CL)I suggest you get a cap tester (an old one) as your next piece of equipment

author: oldway
author_rank: Super Contributor
timestamp: July 10, 2016, 05:52:25 am
content: Quote from: finom1 on July 10, 2016, 03:30:00 amhttp://www.ohio.edu/people/postr/bapix/capchkr2.htmQuoteOnly HM605 has component tester built in.Component tester is useful for diagnosis in semi-conductors circuits, but useless with tubes. (like Huntron 2000 !)

author: finom1
author_rank: Regular Contributor
timestamp: July 10, 2016, 06:49:44 am
content: OK, I will buy ether a Heathkit IT-11 or IT-28 in good condition & the right price.I still need help with an analog meter for guitar amp projects that will be reliable & have features to complete most trouble shooting demands.What would be a better choice:1. Tektronix 465B 100MHz 2-Channel Analog Oscilloscope2. Tektronix 2215A 60MHz OscilloscopeThank you.

author: oldway
author_rank: Super Contributor
timestamp: July 10, 2016, 07:17:43 am
content: Tektronix 2205 (20 Mhz) would be cheaper and is enough to deal with tubes.NB: regarding to new DSO oscilloscopes, it should be noted that failures caused by user errors (eg, surge on the vertical input) are not covered by warranty.On the other hand, there are many complaints on this forum over very expensive repairs of recent DSO oscilloscopes.

author: tautech
author_rank: Super Contributor
timestamp: July 10, 2016, 08:17:50 am
content: Quote from: oldway on July 10, 2016, 07:17:43 amQuite.All the more reason to ensure any choice of DSO is one with 400V capable channel inputs.It must also be stated CRO's are not immune to input overvoltage events either that usually result in blown input FETs.

author: oldway
author_rank: Super Contributor
timestamp: July 10, 2016, 08:57:47 am
content: You buy a CRO and you pay US§100.00.You blow the A channel input, you use then the B channel input (you don't need both channels for working with tube guitar amplifier)When you blow the second channel, you sell the scope for parts for US§50.00You loose only US§50.00

author: ez24
author_rank: Super Contributor
timestamp: July 11, 2016, 01:02:19 am
content: Quote from: finom1 on July 10, 2016, 06:49:44 amEither if it works. Watch out for dirty switches (the contacts).See if you can find one of these if you are going to work with tubes:

author: finom1
author_rank: Regular Contributor
timestamp: July 11, 2016, 01:47:39 am
content: Quote from: ez24 on July 11, 2016, 01:02:19 amLooks like it will exceed the budget for a family just starting out.

author: rstofer
author_rank: Super Contributor
timestamp: July 11, 2016, 02:29:22 am
content: Quote from: finom1 on July 10, 2016, 06:49:44 amI really like the Tek 4xx series. I have a 485 and it is excellent.One of the purveyors of the 2215 scopes on eBay also has a 2235 for about $30 more. Instead of 60 MHz, it is 100 MHz. I realize that the bandwidth is meaningless for audio work but extra bandwidth is always a good thing. My 485 is a 350 MHz scope but I rarely use it beyond 100 MHz.

author: oldway
author_rank: Super Contributor
timestamp: July 11, 2016, 09:48:54 am
content: It is not realistic to use such a true boat anchor with more than 100 tubes for reason of weight, loss of space and electricity consumption.But vacuum tube input stage is really bullet proof.

author: finom1
author_rank: Regular Contributor
timestamp: July 11, 2016, 12:01:27 pm
content: Quote from: rstofer on July 11, 2016, 02:29:22 amThank you for sharing your thoughts.

author: oldway
author_rank: Super Contributor
timestamp: July 11, 2016, 12:19:57 pm
content: I have a 465B, a 2235A and 2236.They are all very good, but in 2235 the power supply operates at high temperature and I installed a fan as on 2236.I saw the prices of these oscilloscopes on ebay.com and they are close to the price of a new DSO.One may wonder in this case if it is worth it.As long as one remains in the range 50 to 100 US§, this question does not arise.But with prices of 250 or higher more shipping, it should be reconsidered.I would never pay such high prices for an analog oscilloscope, it's crazy !

author: finom1
author_rank: Regular Contributor
timestamp: July 11, 2016, 12:52:20 pm
content: Quote from: oldway on July 11, 2016, 12:19:57 pmWell said.

author: rstofer
author_rank: Super Contributor
timestamp: July 11, 2016, 01:13:16 pm
content: Quote from: finom1 on July 11, 2016, 12:52:20 pmWhich brings us back to DSOs and while there are some units that are cheaper than the DS1054Z, they all lack features that may well be worthwhile down the road and the cost difference doesn't justify skimping. Get some 100x probes and call it good.That video of the 555 was kind of fun. I wouldn't have room for such a thing but it's interesting to see how Tektronix built things way back when.

author: finom1
author_rank: Regular Contributor
timestamp: July 11, 2016, 01:54:25 pm
content: Quote from: oldway on July 11, 2016, 12:19:57 pmWell said.

author: oldway
author_rank: Super Contributor
timestamp: July 11, 2016, 03:42:13 pm
content: Quote from: rstofer on July 11, 2016, 01:13:16 pmOr to lower bandwith analog oscilloscopes who are a lot cheaper.Why a 100Mhz scope ?Audio bandwith is from 20 to 20Khz, a guitar tube amplifier hardly works from 50Hz to 10Khz.In the past, I used an IO12 Heathkit of 5MHz and it was everything I needed to test and adjust the guitar amplifiers that I planned and making.Note that I do not recommend this scope.When it was new, it was already a piece of shit.But there are many more modern analog oscilloscopes 20Mhz that would do the job in the range of US § 50-100.

author: finom1
author_rank: Regular Contributor
timestamp: July 11, 2016, 04:00:11 pm
content: Quote from: oldway on July 11, 2016, 03:42:13 pmThank you for your advice. We are just starting out. Is it possible to find a Tested & Calibrated scope shipped under $200?Thanks again!

author: rstofer
author_rank: Super Contributor
timestamp: July 11, 2016, 04:11:54 pm
content: Quote from: finom1 on July 11, 2016, 04:00:11 pmCalibrated might be a stretch but tested, they are all over the place:http://www.ebay.com/itm/Tektronix-TAS-455-Analog-Oscilloscope-60-MHz-2-Channel-Tested-TAS455-/252452065591?hash=item3ac750d137:g:o6gAAOSwMNxXVyYg#shpCntId$37 shipping to me.

author: oldway
author_rank: Super Contributor
timestamp: July 11, 2016, 04:46:48 pm
content: If there is one scope you should NEVER use with tube circuits, nor with high voltage applications, that's the TAS4xx series of Tektronix.Why ?Because it's attenuator is an unobtainium hybrid. If you blow it, it can't be repaired.It is also of low quality, not "made in USA".

author: ez24
author_rank: Super Contributor
timestamp: July 12, 2016, 02:29:50 am
content: This seller usually sells them for less than $200 (but close)http://www.ebay.com/itm/Tektronix-Tek-465B-100-Mhz-oscilloscope-A-Fine-Commercial-Grade-Instrument-/282093392596?hash=item41ae1392d4:g:xL0AAOSwkl5XfpTmI know, I have been bidding on his scopes for years including this one. If you like this one, I will stop bidding (I do not need it - I just cannot stop myself). For some reason or other, I just love the looks of a 465, so it is like a fix that I need. I think it is the red knobs.QuoteI think this means he checked it and it is ok. So this ad is "true"ps I would have saved a lot of money if I bought my first one from this sellerAlso you can enter "refurbished" as a search termhttp://www.ebay.com/itm/Tektronix-465-100-MHz-Dual-Trace-Oscilloscope-Refurbished-/191895903623?hash=item2cade31d87:g:0JcAAOxy--NRqO5TI really do not think this one is "refurbished". To me, refurbished means the caps would be replaced. And if someone did this they sure would say so. The fine print says checked. So this ad is "false"

author: oldway
author_rank: Super Contributor
timestamp: July 12, 2016, 07:45:41 am
content: Tektronix 465 : US§ 395?Gold plated ?

author: ez24
author_rank: Super Contributor
timestamp: July 12, 2016, 05:50:40 pm
content: Quote from: oldway on July 12, 2016, 07:45:41 amIt is the B model, as in bullion as in gold bullionSo yes

author: oldway
author_rank: Super Contributor
timestamp: July 13, 2016, 09:14:10 am
content: Quote from: finom1 on July 11, 2016, 04:00:11 pmI think you don't know what "calibrated" means."Our prices for Oscilloscope calibration service range from:$80.00 to $695.00"https://www.custom-cal.com/TypeInfo.aspx?kn=147&srv=Oscilloscope_Calibration_RepairIf you send an oscilloscope to be calibrated, you probably pay more than §200 only for calibration.

author: ez24
author_rank: Super Contributor
timestamp: July 13, 2016, 07:41:49 pm
content: Quote from: oldway on July 13, 2016, 09:14:10 amQuote.I assume "performance calibrated" is hooking up the probe to the calibrator (below the screen) and adjusting the red dial to match the output. The OP needs to understand this and a real "calibrated" scope is going to cost more than a new Rigol DZ1054The only thing I would expect from this seller is it works and the switches are not dirty. In my experience most do not, that is why this scope will sell for big $$ (FYI I am not bidding any more on it).

author: finom1
author_rank: Regular Contributor
timestamp: July 14, 2016, 03:08:29 am
content: Quote from: ez24 on July 13, 2016, 07:41:49 pmThanks for your help!

author: ez24
author_rank: Super Contributor
timestamp: July 14, 2016, 05:04:04 am
content: Quote from: finom1 on July 14, 2016, 03:08:29 amA long shot. There is this sectionhttps://www.eevblog.com/forum/buysellwanted/Try and place an ad - likeWTB  - An oscilloscope under $200and see what happens

author: finom1
author_rank: Regular Contributor
timestamp: July 16, 2016, 11:25:14 am
content: Someone mentioned a great item to have on a test bench a, " Current Limiter - Dim Bulb Tester ". That was another great idea!Here is a great video, please watch it, if anyone would add anything or wire it differently please provide your ideas to make it better!A Viewer's Dim Bulb Tester Project -Thanks

author: oldway
author_rank: Super Contributor
timestamp: July 16, 2016, 02:55:55 pm
content: This project is totally stupid because:- Why a 5A fuse? the light bulb limits the current and the 5A fuse will never blow.- Why an ammeter? the illumination of the light bulb gives a sufficient idea of the current- Why a switch? totally useless- Why a power meter? Useless, it's crazy to waste money for nothing.- Why an output voltmeter? Useless.This can be very simple: insert a 100W light bulb in the fase wire, that's all....I use it often for testing SMPS I just repaired.Also, if you have a variac with 2A bipolar circuit breaker to protect output (plus eventually an ammeter), it do the job far better and this project is totally useless for tube audio amplifiers.

author: finom1
author_rank: Regular Contributor
timestamp: July 16, 2016, 03:14:55 pm
content: Quote from: oldway on July 16, 2016, 02:55:55 pmThat sounds great. I will take your advice!Would this meter be an asset on a work bench?P3 P4400 Kill A Watt Electricity Usage Monitorhttps://www.amazon.com/P3-P4400-Electricity-Usage-Monitor/dp/B00009MDBU/ref=sr_1_2?ie=UTF8&qid=1468639289&sr=8-2&keywords=P3+International+Kill+A+Watt+Electricity+Usage+MonitorThanks.

author: oldway
author_rank: Super Contributor
timestamp: July 16, 2016, 04:34:26 pm
content: Quote from: finom1 on July 16, 2016, 03:14:55 pmDo you want to measure or calculate efficiency of guitar tube amplifiers ?Better not to do this because efficiency is so low that you will eventually stop with your hobby.For this reason, I answer: for your application, not.

author: finom1
author_rank: Regular Contributor
timestamp: July 16, 2016, 04:59:52 pm
content: Quote from: oldway on July 16, 2016, 04:34:26 pmEfficiency was not the main goal. The main goal is to increase the dynamics, gain & volume. To maximize the full potential of the Vacuum Tube Amp, with the least loss of signal. We don't want to color the tone with complex tone stacks. We are looking for a very organic, open sounding dynamic guitar amp project. We want each project to have it's own voice and not turned into what someone thinks is the ideal circuit!Thank you for all your great guidance & coaching. It has been a real pleasure for our family to read your advice.Thanks again and we look forward to what you have to say.

author: ez24
author_rank: Super Contributor
timestamp: July 16, 2016, 05:49:15 pm
content: Quote from: finom1 on July 16, 2016, 03:14:55 pmWhy not? It is cheap enough and it is fun to have around. You can use it on your refer, coffee maker, TV, etc. just for kicks. Show your kids how much power things use.

author: finom1
author_rank: Regular Contributor
timestamp: July 16, 2016, 07:27:30 pm
content: Quote from: Shock on July 16, 2016, 07:18:27 pmThis is the Variac we purchased; Variac Variable AC Power Transformer 0-130 VAC with Meter (TDGC-1KM) Max.10 A -http://www.ebay.com/itm/121605198781Now we need to build the Dim Bulb Tester.Thank you.

author: tautech
author_rank: Super Contributor
timestamp: July 16, 2016, 08:20:25 pm
content: Quote from: finom1 on July 16, 2016, 07:27:30 pmHere's my knocked together version:https://www.eevblog.com/forum/repair/suggested-for-a-sticky-part-one-comments-or-additions-please/msg470686/#msg470686Some discussion on typical usage:https://www.eevblog.com/forum/repair/tektronix-465b-won't-turn-on/msg563464/#msg563464

author: ez24
author_rank: Super Contributor
timestamp: July 16, 2016, 09:09:14 pm
content: Quote from: finom1 on July 16, 2016, 04:59:52 pmI want to thank you. You asked about a scope and I was going to say check CL. But I thought I should check CL just to see what was there. And guess what - there was a pristine Tek 465B for sale and I got it. Looks like it just came out of a box, no scratches, marks, or scuffs. The seller says it has less than 10 hours on it. And it came with Tek probes (and a current probe ?) and a manual. :-Edit: And an audio cassette tape on how to operate the scope+

author: bitseeker
author_rank: Super Contributor
timestamp: July 16, 2016, 09:53:06 pm
content: Wow, nice score, ez.

author: finom1
author_rank: Regular Contributor
timestamp: July 17, 2016, 04:37:07 pm
content: Quote from: tautech on July 16, 2016, 08:20:25 pmI have now gained allot of incite into what it takes to be effective in the area of our hobby. I personally love the look of old school vintage test equipment, and at the same time I understand the benefits of modern equipment.I am very good friends with two boutique custom amplifier builders who also repair any type of electronic musical equipment. Both rarely us an oscilloscope to build or repair on a daily basses. They always say their senses are first, along with a dim bulb tester, chop stick, signal tracer, multi-meter, cap & transistor tester and the use of jumper wires to isolate a problems has been the most effective way to run their business.So I now realize it's not about what I like, but what equipment & methods to utilize to achieve our goals in a cost effective way. The saving will go towards new purchases of vintage radios, TV's, & organs for project material to convert into guitar amplifiers.Here are just two youtube channels that maximize there dollars;1. The Guitologist -https://www.youtube.com/user/electrictoothsyndrom/videos2. Uncle Doug -https://www.youtube.com/user/Stratosaurus1/videosThanks for sharing your wisdom!

author: oldway
author_rank: Super Contributor
timestamp: July 17, 2016, 06:00:43 pm
content: I see that you begin to understand that we should not have sophisticated measuring instruments for doing good work in the project, construction and repair of tube guitar amplifiers.At the time I was making guitar amplifiers of my own projects (my favorite tubes were EF86 as preamp, ECC83 for baxendale tone control, ECC82 as phase shifter and EL34 as push-pull output - rectifiers: I used BY100 silicon diodes), I had at my disposal that:- A low frequency generator (sine + square wave)NB: square wave is very useful to verify the stability of the amplifier.- A model 8 Avometer- A high impedance meter Hansen UV47- An oscilloscope 5 Mhz Heathkit IO-12E- An adjustable high voltage power supply (self-made)- A variac- A load resistance 8R 50W (self made).I had not tube tester because it was unnecessary, we had commitment to quality tubes, they where not tested, I simply replaced them.No need of distortion meter, the polarization of the final stage was ajusted for minimal anode quiescent current with no visible crossover distortion on the oscilloscope.To repair and modification of old tube amplifiers, you need more of a capacitor tester (at the time, it was useless, capacitors were new)A signal tracer can also be very useful.And above of all, you must have a lot of knowledge, documentation and experience in the field.

author: ez24
author_rank: Super Contributor
timestamp: July 17, 2016, 06:25:18 pm
content: Quote from: finom1 on July 17, 2016, 04:37:07 pmFor those in the know - for this type of work (vintage repair) which of the following would be the most useful:DE-5000or an old evil eye tester ?Seems to me they both are (were) at the top of their game at the time of their sales

author: finom1
author_rank: Regular Contributor
timestamp: July 17, 2016, 06:48:46 pm
content: Quote from: oldway on July 17, 2016, 06:00:43 pmYou finally got this old dog on the right path!!!Thank you!!!

author: oldway
author_rank: Super Contributor
timestamp: July 17, 2016, 08:17:22 pm
content: Quote from: ez24 on July 17, 2016, 06:25:18 pmAn old evel eye tester because greatest concern with high impedance tubes circuit is leakage.Capacitors have to be tested for leakage at working voltage (up to 250V).NB: you need also a knockout hole punch set if you want to add tube sockets.

author: finom1
author_rank: Regular Contributor
timestamp: July 17, 2016, 11:29:19 pm
content: Quote from: oldway on July 17, 2016, 08:17:22 pmYou are so smart. This is the brand we used at Westinghouse;http://www.greenlee.com/catalog/Knockout-Sets/KNOCKOUTS?ps=1000Thank you for all your kindness share your wisdom with us. This is a great start to our learning about electronics while have fun with our new hobby!

author: finom1
author_rank: Regular Contributor
timestamp: July 24, 2016, 05:27:52 pm
content: I need help buying a new Soldering Station.In the old days over 25 years ago, we used $1,000+ soldering stations from Weller & Metcal for defense and NASA work, One Touch Soldering technique had to be followed.I need a soldering stating that will quickly transfer & maintain temperature while de-soldering old solder connections. I do not want to damage components, especially Germanium Transistors when we start building vintage effects pedals for guitar.Once the tip has been properly prepped for soldering, which manufacture will give me the best heat transfer?Some videos;Thank you for any help!

author: Shock
author_rank: Super Contributor
timestamp: July 25, 2016, 01:26:34 am
content: Hakko FX888D has a good tip range (T18 series) and is probably the go to bang for buck station in the US, if you are doing point to point type soldering or high thermal mass such as potentiometer grounds you could use a tip such as the T18 S3 and this will throw out a ton of heat. Other tips though will work just as well.https://www.hakko.com/english/tip_selection/series_t18.htmlThe tips are already tinned you can start using them straight away.

author: finom1
author_rank: Regular Contributor
timestamp: July 25, 2016, 01:35:47 am
content: Quote from: Shock on July 25, 2016, 01:26:34 amGood advice, thank you for sharing!!!

author: nanofrog
author_rank: Super Contributor
timestamp: July 25, 2016, 03:29:40 pm
content: Quote from: finom1 on July 24, 2016, 05:27:52 pmHow much performance do you need?I ask, as the Hakko FX-888D is a nice entry level station, but it's not the greatest performer. Meaning it can tackle 1 or 2 layer boards, and some 4 layer boards (assuming not on heavy ground pours on 4 layer). If you hit the latter case or mechanical solder tabs and so on, it will struggle/exceed recommended dwell time, or flat out be unable to make the joint.So if you need more performance than theFX-888D, or want to do things faster, you'd be better off with the FX-951 instead. It uses cartridge type tips, but common profiles aren't expensive (i.e. $10.47 per). And due to TEquipment's prices & the discount they offer EEVBlog members (I'll PM it to you), it comes in ~$230 shipped (Hakko does not include any tips). The tip selection is also quite extensive, and the plating is one of the thickest, if not the thickest out there giving you a very long service life (i.e. 10 years on lead based alloys is common with basic tip care). Tip changes are easy too.The following may be of some help...

author: oldway
author_rank: Super Contributor
timestamp: July 25, 2016, 04:55:18 pm
content: I do not understand why you need a new soldering station to work with repair and modification of tube guitar amplifiers.It has nothing to do with defense or NASA solder specifications and requirements.I had an ERSA 30W (with ersadur tip) for most of the solders and a big 300W soldering iron for chassis soldering.Both were very cheap.No need to spend hundreds of dollars for soldering.If you really want a soldering station, there is the indestructible TCP-s WELLER I particularly recommend.But you will need in any case another soldering iron of 200 or 300W for chassis soldering.To solder germanium diode or transistor, use a clamp or an alligator clip as thermal path to reduce risk of overheating of the semi-conductor and let them with long wire, don't cut the wire.

author: finom1
author_rank: Regular Contributor
timestamp: July 25, 2016, 06:19:17 pm
content: Quote from: oldway on July 25, 2016, 04:55:18 pmAlways great advice!!! Thank you!

author: rsjsouza
author_rank: Super Contributor
timestamp: July 25, 2016, 07:27:57 pm
content: I also have a FX888 and got the larger tips mentioned by Shock - they work well for larger PCB areas.For the offending job that requires more power, however, I got myself aWeller 8200 kit- it heats instantaneously, works very well but the enclosure tends to become hot when used for a long time (about 1/2 hour or so).

author: ez24
author_rank: Super Contributor
timestamp: July 25, 2016, 10:03:18 pm
content: This is my go to iron, it is light, carries a lot of heat (good for wiring in tube sockets) and heats up fast:https://www.amazon.com/WELLER-COMPLETE-700%C3%82%C2%B0F-POWER-CHISEL/dp/B00DKEYPOU/ref=sr_1_2?ie=UTF8&qid=1469483856&sr=8-2&keywords=weller+gt7aFor PCB I use a cheap 30w iron - for really heavy work, like splicing 6ga wire, I use the large Weller:https://www.amazon.com/Weller-D650-Industrial-Soldering-Gun/dp/B000JEGEC0/ref=sr_1_18?ie=UTF8&qid=1469483984&sr=8-18&keywords=weller+soldering+ironIf you get into SMD work then you probably will need a soldering stationEdit: my go to has a better tip than the heavy duty one

author: tautech
author_rank: Super Contributor
timestamp: July 25, 2016, 10:47:44 pm
content: If you happen to stumble upon an English Antex X25, they're a good little iron too. Despite being rated only @ 25W they box above their weight for a lightweight mains powered pencil iron. I'd happily use one on valve based work, P to P and tag strip work.US readers will know if they were available in 110V versions, only 230V here.

author: nanofrog
author_rank: Super Contributor
timestamp: July 26, 2016, 05:29:27 am
content: Quote from: tautech on July 25, 2016, 10:47:44 pmAccording to Antex's site, they're only offered in 12V, 24V, & 230V versions (no P/N's listed for 12V & 24V, so I assume they're special order).

author: tautech
author_rank: Super Contributor
timestamp: July 26, 2016, 05:31:38 am
content: Quote from: nanofrog on July 26, 2016, 05:29:27 amStalking AGAIN.

author: nanofrog
author_rank: Super Contributor
timestamp: July 26, 2016, 05:36:01 am
content: Quote from: tautech on July 26, 2016, 05:31:38 amCan't help it... stupid insomnia ().

author: finom1
author_rank: Regular Contributor
timestamp: July 26, 2016, 11:24:18 am
content: OK, we need the help of the geniuses here that have helped us have a vertical start up. This all started by reading on line about favorite capacitor testators that test at operating voltages.The question is, which capacitor tester is better & has more features;1. Military ZX-11or2. Military ZM-30/UThank you for sharing your wisdom!

author: oldway
author_rank: Super Contributor
timestamp: July 26, 2016, 02:15:01 pm
content: I would choose a cheaper IT-28 Heathkit. (or IT-11)More informations here:http://www.antiqueradios.com/forums/viewtopic.php?t=3209

author: finom1
author_rank: Regular Contributor
timestamp: July 30, 2016, 01:44:39 am
content: I just watched these videos about testing capacitors;1. Testing Capacitors part 1,2. Testing Capacitors Part 2,It's great listening to him!I look forward to hearing what you think?

author: ez24
author_rank: Super Contributor
timestamp: July 30, 2016, 06:43:17 am
content: Quote from: finom1 on July 26, 2016, 11:24:18 amOnce you decide on what you want, you may want to ask forum members if anyone has one for sale. You would stand a better chance of getting one that works. The military ones are cool looking. Since there has been no responses about them, you could start a new topic on just them. That way they would get more attention.

author: oldway
author_rank: Super Contributor
timestamp: July 30, 2016, 09:44:48 am
content: A lot of vintage measuring equipment here !On old tube devices, I am in favor of change only what is necessary .Indeed, if one wants to do preventive maintenance, you end up having to completely redo the amplifier and change almost all components.That's:-all electrolytic for an obvious reason-all capacitors because of the risk of leakage-all carbon resistors because they were sensitive to moisture and were driftingMy philosophy is different: change only what is essential.So,1) change all the low voltage electrolytic capacitors ... no need to measure them, simply automatically change them... They are cheap, easy to buy and there is also a very little number in tube amplifiers.2) check for leaks the grid / anode coupling capacitors. (the exact value of the capacity is not important)3) For the high-voltage electrolytic capacitors, check the ripple.If the ripple is low, do not change them.If the ripple is too high, either change them or solder an additional electrolytic capacitor to the terminals of the old capacitor.4) for carbon resistance, do a functional test ... if everything is ok, do not change nothing even if the value of resistance has changed.This preserves the amplifier to stay the most original like as possible .

author: finom1
author_rank: Regular Contributor
timestamp: July 30, 2016, 10:58:20 am
content: Quote from: oldway on July 30, 2016, 09:44:48 amGreat particle advice to follow!It's very clear after going back and reading all your advice that we should make a "Start Up Check List", to follow for each piece of equipment we work on!1. Using a Variac & Dim Bulb Tester to check for shorts & re-form capacitors.etc...Thank you for sharing your wisdom!!!

author: finom1
author_rank: Regular Contributor
timestamp: July 31, 2016, 07:41:14 pm
content: What is the best Signal generator to use for vintage vacuum tube work we will be doing?Thank you for your advice!!!

author: tautech
author_rank: Super Contributor
timestamp: July 31, 2016, 09:07:52 pm
content: Quote from: finom1 on July 31, 2016, 07:41:14 pmI'm unsure if you'd want/need isolation.....common ground connection shouldn't present any problems but care is needed if the signal reference need be elevated from ground.The Siglent SDG5000 series offers isolated outputs but most probably it's a unit far in excess of your needs.For audio, any unit capable with a 20 Hz -50 KHz sine wave should suit your needs but if there's any digital control waveform needs you might want to look at those that can offer square waves or pulses up to 1 MHz or so.

author: ez24
author_rank: Super Contributor
timestamp: July 31, 2016, 09:15:21 pm
content: Quote from: finom1 on July 31, 2016, 07:41:14 pmIf you are going with vintage repair equipment check this outhttp://www.ebay.com/itm/Vintage-Boonton-Radio-Type-211-A-Serial-103-Crystal-Monitored-Signal-Generator-/371489528620?hash=item567e805b2c:g:jm0AAOSw7hRWPRD6search ebay on "vintage signal generator"Some really cool looking stuff.It seems if you equip your lab this way and everything works, it would increase in value with time (ie a good investment). Plus during Halloween you could set up a haunted house with an electric chair as the main attraction and all this equipment around the chair. See if you can get any kids to sit in it. Then when you get good - give them harmless shocks using your vintage equipment.

author: finom1
author_rank: Regular Contributor
timestamp: July 31, 2016, 09:21:30 pm
content: Quote from: tautech on July 31, 2016, 09:07:52 pmThank you for sharing!I just watched this video and I am totally confused -Look at all the equipment used just to generate the signal? I am new at this, but how many pieces of test equipment is needed to send pure sine wave into one of our tube amp restorations/ guitar amp to check the output, wattage & distortion?Thank you.

author: bitseeker
author_rank: Super Contributor
timestamp: July 31, 2016, 10:14:35 pm
content: Quote from: finom1 on July 31, 2016, 09:21:30 pmThat video is about comparing two different models of signal generators and a function generator. You'd only need one generator that covers the audio spectrum and has a lower THD than the equipment you'd be working on.

author: finom1
author_rank: Regular Contributor
timestamp: July 31, 2016, 10:20:09 pm
content: Quote from: Shock on July 31, 2016, 10:01:20 pmWOW, great "Start up Check List".Would it be a good idea to have two separate check lists?1. Pre-Power Up Check List; loose wires, burned components/wires, blown fuse, etc... visual inspections.2. Power Up Check List, as stated eloquently above.What do you think?Thank you for sharing!!!

author: finom1
author_rank: Regular Contributor
timestamp: July 31, 2016, 10:21:56 pm
content: Quote from: bitseeker on July 31, 2016, 10:14:35 pmThank you for sharing!!!

author: Shock
author_rank: Super Contributor
timestamp: July 31, 2016, 10:31:12 pm
content: Quote from: finom1 on July 31, 2016, 09:21:30 pmSignal/Frequency/Function/Audio/Waveform generator to generate an audio signal.Multimeter/Voltmeter to measure the output voltage and then calculate the wattage.Dummy load so that you can take accurate and convenient output measurements (at high volume it's a necessity).Distortion analyzer to measure THD.We are starting really to go back to things discussed on the first page, but you can use any audio device to play a test signal to get yourself started. There are software audio generators and analyzers.The other things he has on that rack I've seen are an oscilloscope, spectrum analyzer, frequency counter and an attenuator.

author: Shock
author_rank: Super Contributor
timestamp: July 31, 2016, 10:42:54 pm
content: Quote from: finom1 on July 31, 2016, 10:20:09 pmSure, put numbers next to my paragraphs if it makes it easier to understand.

author: ez24
author_rank: Super Contributor
timestamp: July 31, 2016, 11:32:26 pm
content: If space is a problem you could try this with a $50 tablethttps://play.google.com/store/apps/details?id=com.keuwl.functiongenerator&hl=enFor audio work, apps can do a lot

author: finom1
author_rank: Regular Contributor
timestamp: August 01, 2016, 12:00:18 am
content: Quote from: ez24 on July 31, 2016, 11:32:26 pmGreat, this solves the pure sine wave with low distortion problems!!!Thanks!!!

author: ez24
author_rank: Super Contributor
timestamp: August 01, 2016, 12:07:23 am
content: Something that might be of helpyou never know if one of these will show up (transistor)https://www.eevblog.com/forum/beginners/introduction-to-electronics-course-free-or-$50-starts-aug-22/

author: oldway
author_rank: Super Contributor
timestamp: August 01, 2016, 01:57:46 am
content: There is absolutely no need to measure the harmonic distortion of a tube guitar amplifier.As I have already written and as calexanian has also confirmed, it would just adjust the bias of the output tubes so that there are no visible crossover distortion on the oscilloscope.So all audio generator with sine / square output is good, even the cheapest one.Quote from: calexanianhttps://www.eevblog.com/forum/projects/fender-deluxe-reverb-repair/Nb: Square wave is needed to check the stability of the amplifier....

author: finom1
author_rank: Regular Contributor
timestamp: August 01, 2016, 03:58:34 am
content: Quote from: oldway on August 01, 2016, 01:57:46 amOK, got it. For some reason my head hurts now!!!

author: oldway
author_rank: Super Contributor
timestamp: August 01, 2016, 07:14:06 am
content: The problem you have is that you do not have a clue about what you need to do to transform old amplifier in tube guitar amplifiers.To find out what you need as test instrument, you must "put your hands in the dough" and you will realize for yourself what you need.So, first try to do the job, look for experienced tube technicians in your neighborhood and equip you gradually according to your needs.Obviously you will realize quickly that it is not necessary to have high precision instruments and that the problems are simple and basic ....One of your main problem is the fact that the tubes in general are no longer manufactured.As wrote calexanian, we used the tubes beyond their maximum ratings and they were often replaced after each concert.I remember amplifiers that worked with the anodes of pentodes dark red hot ! ....So one of the first requirements seems to be a tube tester because they have become scarce and expensive.Another principle: a tube circuit is generally quite tolerant about the value of the components.The characteristics of the tubes change during aging and circuits are scheduled to continue operating even in this case.So do not change all resistances only because they are out of tolerance, it is ridiculous and absurd.Make a functional test and do not change the components if the functional test proves that's unnecessary.

author: finom1
author_rank: Regular Contributor
timestamp: August 01, 2016, 11:47:36 am
content: Quote from: oldway on August 01, 2016, 07:14:06 amGreat advice, thank you!!!

author: Enigma-man
author_rank: Regular Contributor
timestamp: August 01, 2016, 04:16:42 pm
content: @finom1:Hello, fellow retiree...I don't know if anyone mentioned this in a previous reply and apologies if that is the case.Get an isolation transformer. I see you are in the USA so a 120VAC in and 120VAC out at about 2.5 amperes or higher.Everyone who dicks around with electronics, either hobbyist or professional should have one as the most important pieceof gear. Owning one could save your life. It did for me. Back in the very early 90's I was asked to repair computer monitors.The switching supplies run right off the AC line. I got a few shocks and a few injuries from pulling my hand away.Needless to say, I don't futz around anything until it plugs into the isolation transformer. Sure you may get an electricshock but it won't be fatal. The isolation transformers are not cheap, but if your life isn't worth spending $100 on somethingsafety related.... well, good luck to you.Here's a pic of my homemade unit with a 5 Amp Variac inside. Make sure you have the necessary skills to wire up the AC.I used a square receptacle, but one could use a standard two outlet wall receptacle.Remember, PLAY SAFE !!!!

author: finom1
author_rank: Regular Contributor
timestamp: August 01, 2016, 04:38:25 pm
content: Quote from: Enigma-man on August 01, 2016, 04:16:42 pmI purchased this last year - Variac Variable AC Power Transformer 0-130 VAC with Meter (TDGC-1KM) Max.10 Ahttp://www.ebay.com/itm/Variac-Variable-AC-Power-Transformer-0-130-VAC-with-Meter-TDGC-1KM-Max-10-A/121605198781?_trksid=p2047675.c100009.m1982&_trkparms=aid%3D0%26algo%3DDISC.MBE%26ao%3D1%26asc%3D20131227121020%26meid%3D18133bf93c084b9195b6a2b782367e86%26pid%3D100009%26rk%3D1%26rkt%3D1%26sd%3D301960068642Does this have the isolation transformer in it?Thank you for helping us!!!

author: nanofrog
author_rank: Super Contributor
timestamp: August 01, 2016, 04:44:01 pm
content: Quote from: finom1 on August 01, 2016, 04:38:25 pmUnfortunately, that unit is non-isolating.

author: finom1
author_rank: Regular Contributor
timestamp: August 01, 2016, 04:59:18 pm
content: Quote from: nanofrog on August 01, 2016, 04:44:01 pmOK, it was less then $100. I will sell it.What brand & model should I buy that has been a test bench standard over the years?Thank you for sharing!!!

author: oldway
author_rank: Super Contributor
timestamp: August 01, 2016, 05:03:42 pm
content: There is no switch mode power supply in guitar tube amplifiers ....Amplifiers have already an isolation power transformer, no need of a second one....People are answering this topic without reading and knowing what you intend to do....I remember that you and your son intend to modificate old tubes amplifiers to make guitar amplifiers.

author: john_p_wi
author_rank: Regular Contributor
timestamp: August 01, 2016, 05:32:12 pm
content: I've been building guitar amps and pedals for more than 20 years. As I get older, I find that I am more into the convenience of things than the equipment. Most of my test gear (I have two benches set up with nearly identical equipment) is of 80's and 90's vintage, Tek scopes and Wavetek 164 signal generators.Make sure that your bench is set in a way that DVM's, scope probes, dummy loads, signal generators etc can be easily accessed without the spaghetti nightmare of cable entanglement. Buy Fluke probe clips that you can hook on to the test circuit and leave while you test under power. I can't stress enough the importance of test lead management and dedicated leads for each piece of equipment. The last thing you want to do is have a tangle of wires over an open chassis with 500 volts exposed. Also have dedicated amp cradles, even if it is wood blocks etc, vises for the pcbs etc. I can't express the importance of being methodical and deliberate. Trust me, whatever size bench you think you will need - double it. Most likely you need some type of lighted magnifier too.Regarding the soldering iron question a few pages back, this is the one area that I spoiled myself with a good Metcal with desoldering gun. I have 10 tips or so with the Metcal and can solder anything from 0402 surface mount to the heaviest ground plane connections by changing the tips. Look at something like the MX-5251 - when using it with the old tag board / eyelet circuit boards it is very convenient to pull the component lead out of the eyelet using the soldering hand piece then immediately "clean" out the eyelet with the vacuum desoldering gun. It is also great for cleaning out the solder lugs on pots etc along with the normal pcb desoldering work.Finally, all of the info regarding variacs, iso transformers etc is solid. I also have several multi channel power supplies for pedals and a large 20 volt x 20 amp power supply for heater strings etc. Good, solid, working equipment of 20+ years is more than adequate. I'd focus more on quality test lead sets, scope probes, patch cables etc - there is nothing more frustrating than second guessing / trouble shooting your cables / probes.Good luck.

author: Enigma-man
author_rank: Regular Contributor
timestamp: August 01, 2016, 05:35:37 pm
content: @finom1:You may as well keep the Variac and attach the isolation transformer to the Variac. I never came across something that had an isolation transformer and Variacboth in one box.@oldway:I know that finom1 plans to make cigar box amplifiers for his family and about guitar amps with power supplies.It is still connected to the AC line when connected to the Variac and the AC supply is not isolated. That is where you mightget electrocuted while poking around in the primary should you forget to unplug the unit from the Variac.My concern is safety and accidents do and will happen. What people do or do not with information is up to them.Everyone makes mistakes, they don't have to be fatal.Better safe than dead.

author: oldway
author_rank: Super Contributor
timestamp: August 01, 2016, 06:08:01 pm
content: Quote from: Enigma-man on August 01, 2016, 05:35:37 pmDid you ever work with tube amplifiers ? I think not !!!!!There are a lot of components who are at 300 V and more, up to 800V dc (I have seen a public adress amplifier with EL34 working with 800V anode voltage !), in reference with chassis ....Only very few components are on main voltage: input fuse and on/off switch...This is a minor concern.If anyone does not work with safety, he can't repair or modify tube amplifiers.This is a very dangerous kind of equipmentsAn isolation transformer does not improve substantialy the safety in the case of tube amplifiers.It is very fair to have principles, but you have to think if they are applicable in this case.

author: Enigma-man
author_rank: Regular Contributor
timestamp: August 01, 2016, 06:44:28 pm
content: @ all:FWIW:I was just trying to help after seeing finom1 was asking a lot of questions based on his experience.Recently I acquired an Eldorado Electronics 4.5 digit voltmeter with Nixie readouts. It's from the 70's and I had no service data.While working on a problem with the analogue board, my hand brushed against some foil traces from another pc board carrying120VAC. I got quite a jolt and without the isolation transformer... I might not be typing this. I am very careful around electricitybut things happen no matter how good or careful you think you are.Good luck with your equipment search and amplifier projects finom1 and son.If I have anything further to contribute I will PM you.There is more than enough information here and likely more to come from others to steer you in the right direction or confuse you further...Take care.

author: oldway
author_rank: Super Contributor
timestamp: August 01, 2016, 07:47:30 pm
content: Speaking about safety:It is obvious that choosing tube technology as first experience in electronics is not a right choice.Risks are high because of high voltages used in tube technology.I hope finom1 knows this and that he assumes the responsability of his choice.He should learn about safety and pay attention to what he do.For exemple, never touch a component and the chassis at the same time. One hand in the pocket is a very good safety rule.Beginning with help of somebody who has experience in tube technology would be very helpful.QuoteI don't agree, you must learn to prevent accidents to happen and that's possible.Use your brain, work with safety and pay attention to what you are doing.I worked all my life with high voltage, high power electricity and electronics, I would not be alive anymore if I had not learned to prevent accidents. (High voltage tests up to 150Kv, 120 Kva installed power test equipment, tests of 3000V 1500A rectifiers, test and repair of dc drives up to 8000A 550V dc, No-breaks up to 1 Mva, industrial battery chargers up to 600A 500Vdc, inverters, SMPS, ....)

author: john_p_wi
author_rank: Regular Contributor
timestamp: August 01, 2016, 09:45:45 pm
content: oldway, Enigma-man is only trying to be helpful. One thing that is concerning is that the OP has the intent to modify old radios to guitar amps, if I'm not mistaken some of these were transformerless. In this scenario, was the line not directly connected to the heater string and the heaters voltages set in such a way that the series connection of the tubes equaled the line voltage? In this case I believe that the "neutral" was directly connected to the chassis. IF a non-polarized plug or the duplex was wired incorrectly this could potentially put line voltage on the chassis, especially since the "neutral" was either terminated at the chassis or was connected via caps. In cases like this, an isolation transformer is a must, but is not a substitution for a proper protective earth and knowledge.Agreed, knowledge and safety are paramount - unfortunately there are very few versed in these old radios / amps today, and all cautionary advice should be welcome.

author: oldway
author_rank: Super Contributor
timestamp: August 02, 2016, 01:34:14 am
content: Finom1 wrote that he and his son wantto build a hi-quality less then 150 watt ampI have a couple of Hammond & Wurlitzer amps that we want to convert into Cigar Box Guitar amps!!!Nothing to do with "old radios" .....Those old transformless radios had a class A output stage between 2 to 5W audio power.This has absolutely no interest to be converted as guitar amplifier.Moreover, it would be difficult if not impossible to do this because the tube filaments were connected in series to run on the mains voltage.It should therefore be necessary to leave all the high-frequency and intermediate-frequency tubes which would be absurd as they would become useless.Besides, finom1 never said he wanted to convert old radios in guitar amplifiers and it would be very unsafe and lethal as the electric guitar is conected to the chassis of the amplifier.Finom1 was ready to sell his variac because it is not isolated....One of the most important equipment, he would sell it.You call this be helpful ?

author: john_p_wi
author_rank: Regular Contributor
timestamp: August 02, 2016, 02:58:04 am
content: Alright, let's keep this in line for the OP. IF he plans to build cigar box guitars 2-5 watts is plenty. 5 watts through a modern 4x12 cab with efficient speakers will make your ears ring. Trust me I know.Additionally, 5 watts SE can be a glorious thing. Try it. You'd be amazed at how many albums have been recorded with such an amp.I don't have a dog in this hunt, nothing to prove - just trying to help a newbie out who wants to spend time with his kid which is priceless. Please don't scare him off - let's nurture and educate the father / son team without the measuring stick bs - we all started somewhere and had mentors along the way, I can certainly name mine.Honestly the fastest way to learn is with a few solid state parts and a LM386 building a noisy cricket amp with a simple jfet buffer in front of it. A very loud and cool distortion at 1/2 watt that will fill the cigar box vibe while teaching the basics of amplification, grounding, shielding and decoupling at 9 volts dc. All completely safe.

author: finom1
author_rank: Regular Contributor
timestamp: August 02, 2016, 03:02:41 am
content: Thanks everyone for looking out for our safety.We did pick up a couple of vintage upright radios around 3' tall. Wattage was 100 watts and up. No small radios so far, it just turned out that way! WE also have some grate vintage 12" & 15" speakers from organs. All three radios have 12" speakers in them. They all have room for 15" speakers inside.We have a bunch of vacuum tube organ chassis, that we accumulated over the last year.So we have parts, we then needed a safe test bench for the long haul. Everyone here has been making this happen for us. We now have a Pre-Start Up & Start Up Check List. Our safety awareness has increased immensely! Thank all of you for that!!! WE also made great Simpson meter purchase.I am waiting for two people to get back to us concerning capacitor testers. One person has a Heathkit IT-28 the other person has a Eico 950B both around the same price shipped.Thanks for keeping us safe and sharing the wisdom you have attained over the years by repairing & building electronic equipment . It's very exciting!Thanks again!

author: finom1
author_rank: Regular Contributor
timestamp: August 02, 2016, 03:20:47 am
content: It all started over a year ago. We were watching people turn small radios into cigar box & lunch box guitar amps. WE loved the idea!!!Then we started watching The Guitologist on youtube, that was crazy fun for us to watch. Then watching people taking someones electronics headed for the junk yard and creating something new with the parts.I just thought this would be a great way to share some of life's experiences building guitar amp projects with my son while in retirement.Thanks again to all who have taken the time to share with us!!!

author: Shock
author_rank: Super Contributor
timestamp: August 02, 2016, 06:08:57 am
content: Quote from: finom1 on August 02, 2016, 03:20:47 amFirst video I see, transformerless design.

author: oldway
author_rank: Super Contributor
timestamp: August 02, 2016, 09:36:32 am
content: QuoteIf you mean that output audio power was 100W and up, there is something terribly wrong.NB: With tube amplifiers, output power is always specified as rms power. (root mean square).Here are the values of output power you can hope within ratings from the most used audio tubes:http://tubedata.tubes.se/- EL84 = 6BQ5 Class A: 4.5WrmsClass AB (2 tubes push-pull) : 11Wrms- EL34 = 6CA7 Class A: 8.7WrmsClass AB : 35 Wrms- 6V6 Class A: 4.5WrmsClass AB: 13.5 Wrms- 6L6 = 7027 Class A: 6.5 WrmsClass AB: 34 Wrms- KT66 Class A: 5.8 WrmsClass AB: 30 Wrms- KT88 = 6550 Class A:Class AB: 70 Wrms- 807 Class AB: 75Wrms- 7591 = 7868 Class AB : 37 Wrms- 5881 Class A: 6.5 WrmsClass AB: 18 Wrms

author: finom1
author_rank: Regular Contributor
timestamp: August 02, 2016, 10:29:07 am
content: Quote from: oldway on August 02, 2016, 09:36:32 amI purchased a 8'x8'x20' shipping container a few months ago so I could finish the basement to make room for a work area. The chassis and radios are in there. I have plastic totes full, stacked up on the radios. I have to turn them around and see if I can find a name plat & how many/what type of power tubes are being used. That way I can provide more accurate information to you. Some of the organs had metal name plates with 150 watts and up on them but nothing on the tube chassis themselves. Now going by your tube breakdown I will know close to what the output is for each chassis.Two organ name plates on my desk have on them, Lowery Organ 115 volts 60 cy 2.5 amps 275 watts, accessories 4.1 amps 500 watts ( this had multiple tube chassis in it) & The Conn Organ volts 115 herts 60 watts 140 amps 5.Thanks for the detailed break down!!!

author: oldway
author_rank: Super Contributor
timestamp: August 02, 2016, 11:24:17 am
content: Ok, here we are ....the wattage you said, it is the power consumption and not the output power....That's very different because tube amplifiers have a very very low efficiency.

author: finom1
author_rank: Regular Contributor
timestamp: August 02, 2016, 01:01:14 pm
content: My son just said I could have this - Transmation Digital Calibrator/Process Signal Indicator, 1045 -http://www.ebay.com/itm/Used-Transmation-Digital-Calibrator-Process-Signal-Indicator-1045-/191411160754?hash=item2c90fe86b2:g:ffAAAOSwYshUY5TyHe restores cars, trucks & motorcycles and this was in one of the trucks. He buys vehicles that have problems, fixes them then sells them to afford the next one at a higher starting point.I do not know what it is or how to use it. Is it something I should keep for our hobby or sell it to buy a scope?Thank you for any advice!

author: rsjsouza
author_rank: Super Contributor
timestamp: August 02, 2016, 01:53:14 pm
content: finom1, given what you already have or plan to have (a DMM and a power supply), I don't think this calibrator will be of much use. I would sell it and save for the oscilloscope or even increase the budget for a better one!

author: finom1
author_rank: Regular Contributor
timestamp: August 02, 2016, 10:41:59 pm
content: Quote from: rsjsouza on August 02, 2016, 01:53:14 pmGreat advice, I will do that. I found a pdf manual. I have to find some leads then I will put it on ebay.Thanks!

author: finom1
author_rank: Regular Contributor
timestamp: September 04, 2016, 04:17:34 pm
content: I wolud like to personally thank everyone who has shared their wisdom with my son and I.I would like to especially thankOldwayfor going out of his way to help us!!!There was allot of Head-Banging going on around here!!!I will be uploading pictures of test bench equipment & other items. I will also provide a list.Thanks again everyone.

author: finom1
author_rank: Regular Contributor
timestamp: September 04, 2016, 04:19:38 pm
content: Here are a couple more.Thanks again!!!

author: finom1
author_rank: Regular Contributor
timestamp: September 04, 2016, 04:22:20 pm
content: Here is a couple more.Thanks again!!!

author: finom1
author_rank: Regular Contributor
timestamp: September 04, 2016, 04:30:33 pm
content: The last for now. The Qty of 3, 5 drawer file cabinets are full of Radio & TV Repair Manuals and Schematics, hundreds of them!!!Oldway, I got the B&K Precision 1476A Scope for $50 in its original box with test leads & manuals. They said it was on display and never used. The line cord was never unwrapped from the scope. It had Styrofoam stuck to it still!!!Thanks again for all you guidance!!!

author: finom1
author_rank: Regular Contributor
timestamp: September 04, 2016, 04:45:47 pm
content: Oldway, I forgot these pictures. Could you stop over to the US and upgrade this so it will calibrate to 5% Tolerance?Thanks again for all your help and patience!!!

author: oldway
author_rank: Super Contributor
timestamp: September 04, 2016, 07:55:44 pm
content: That's great, you and your son will have a lot of fun.You could not do better.Back in the old good time when electronics was an art more than a science.Congratulations.

author: finom1
author_rank: Regular Contributor
timestamp: September 04, 2016, 08:36:45 pm
content: Oldway,Bless you for sharing your wisdom with us!!!I have to finish the basement including a full bath for my wife ( The Boss) then I will start a new subject of where this one has taken us!!!Thanks again!!!

author: finom1
author_rank: Regular Contributor
timestamp: September 04, 2016, 09:08:48 pm
content: Oldway,This will be arriving on Tuesday - Vectorviz WP-30 combination isolation transformer and variac -https://www.youtube.com/watch?v=d_XZD8Sow6E.I will post the picture after I unpack it.Thanks again for your help!!!

author: bitseeker
author_rank: Super Contributor
timestamp: September 05, 2016, 07:50:27 am
content: @finom1: You guys scored a ton of goodies! If you can't have fun with all that cool gear and parts, you're doing it wrong.Looking forward to seeing your projects.

author: finom1
author_rank: Regular Contributor
timestamp: September 05, 2016, 09:07:38 am
content: Thank you.We tried to take the advice and guidance that everyone was giving us and put it into action!!!This is a great place for like minded people to share their wisdom to help the next generation to carry on the Electronics Restoration & Repair. Just very friendly people, willing to explain in a way that helps a total beginner how to do things and do them safely!!!WE hope to contribute what we are learning through our start up with our new Test Bench project so we can help others start up, as you and others have helped us!!!Thanks again for sharing your wisdom with us!!!

author: oldway
author_rank: Super Contributor
timestamp: September 05, 2016, 11:47:23 am
content: Now, you first "electronic" job would be to test and repair all your measuring intruments.After so many years, I believe they need for sure some new electrolytics capacitors.For low voltage capacitors, you may replace all of them, for high voltage, measure the capacitance and ripple and if it is out of tolerance, replace them.See here for the Eico 377:http://www.johngineer.com/blog/?p=1193

author: finom1
author_rank: Regular Contributor
timestamp: September 05, 2016, 12:43:12 pm
content: I am in the process of buying the Electrolytic caps for the Eico 950B & 1% Precision resistors.Wow, the 8 uf 525 wvdc & 4 uf uf wvdc are expensive and hard to find over here in US.I was also going to recap the Heathkit Regulated Power Supply Model PS-4.C1 = 20-20 uf 350 wvdc, to hard to find so I was going to use Qty - 2 of 20 uf 450 vdc $11.11 eachC2,C3 70 uf 450 vdc $ 2.79 eachC4,C6 20 uf 450 vdc $11.11 eachC5, 40 uf 450 vdc $11.22I got the unit free when I purchased the file cabinets for $3.00 each. He was glade to move the extremely heavy file cabinets. The gentleman was closing his repair shop of 40 years and was moving out of his warehouse of 17 years.When the Vector Viz WP-30 comes in, I think I will try to reform the Electrolytic caps first for the PS-4 before I buy new ones!What do you think of that idea to try to save money, reforming the Electrolytic caps?Looking forward to hearing how you would handle this expensive restore for a piece of equipment I am not keeping. I will sell it on ebay.The Vector Viz WP-30 Variable Isolation Transformer will be used instead.Thank you!

author: oldway
author_rank: Super Contributor
timestamp: September 05, 2016, 01:02:12 pm
content: My philosophy of repair is to replace only what really is needed.The only thing I always replace without testing are the low voltage electrolytics capacitors because they are cheap and easy to buy.For resistances, I only replace them if it is necessary.You will certainly measure that these old carbon resistances are often drifting but it does not always change the correct working of tube circuits.The tube circuits are very tolerant on value of the resistances and voltages.For high voltage electrolytics capacitors (mostly in the power supply) , ESR has pratically no influence on working of tube circuits.Only check the value of capacitance, if correct, they don't need to be replaced.Never power on an old tube equipment directly on full mains voltage.Apply progressive voltage with your variac, beginning with 50% of nominal voltage and increasing it of 10% every hour up to nominal voltage.Look if current is right and if rectifier tube anodes don't became red hot.This is enough, you don't need to reform the electrolytics capacitors.

author: finom1
author_rank: Regular Contributor
timestamp: September 05, 2016, 01:37:45 pm
content: Thank you, I will follow your advice.Thank you for sharing!!!

author: Johnny10
author_rank: Frequent Contributor
timestamp: September 17, 2016, 10:40:07 pm
content: I think those caps you were quoting prices on were for HI-FI audio quality.Tryhttps://www.tubesandmore.com/products/capacitors?filters=Type%3DElectrolyticLarge selections of parts at reasonable and unreasonable prices.You have a great selection of equipment for your hobby.I started out in a similar way... not having a lot of experience in tube equipment and then buying and repairing a lot of older equip.That IT-28 capacitor tester you are looking at works great. I just bought an old unit for 14 dollars and have restored it. It is very quick at checking for leakage, slow for finding capacitor value ! And really accurate. I love the green magic eye !But I also restored a Sencore LC-102 which is quite fast.Good Luck on your journey.

author: finom1
author_rank: Regular Contributor
timestamp: September 18, 2016, 02:26:37 am
content: Thank you for that information!!!

author: finom1
author_rank: Regular Contributor
timestamp: January 23, 2017, 02:50:22 pm
content: I have a question about what to do when it comes to Vintage Capacitor Analyzers.I was looking at a Sencore LC-53 Z Meter Capacitor Inductor Analyzer on ebay. It looks like it will go for around ~$200 looking at history.Should I buy the Sencor LC-53 Z, then sell the - Solar Capacitor Analyzer, Eico 950B, PYRAMID ELECTRIC CRA-1 CAPACITOR RESISTOR ANALYZER that I bought (Total cost ~$150)?If I buy the Sencor, then I could restore and sell the other testers on ebay for more then I paid for them.I guess my question is, should I;1. Buy the Sencor and sell the other Capacitor Testers.2. or Just keep the best out of the Vintage Capacitor testers I have.Thank you for your input.

author: Johnny10
author_rank: Frequent Contributor
timestamp: January 23, 2017, 04:05:48 pm
content: Hey Finom,I was just reading the posts over, you have had 4 months with all the equipment and parts you purchased, have you built any amplifiers yet?As for cap testers... why get rid of the units you have?For my tube amps the old testers work fine for me.For the micro-controlled electronic projects, I do like the Sencore LC102 unit I rebuilt.The Sencore units are very pricey since the repairs have been posted on the forum.

author: finom1
author_rank: Regular Contributor
timestamp: January 23, 2017, 04:30:41 pm
content: Good advice, I will just keep the best of the ones I have and sell the rest.I have not built my Electronics Repair Room yet, The Boss(My Wife) wants me to finish her side of the basement first. I have installed a water treatment system, for softening/PH/Hardness/Filtration etc...Bought a one piece shower and aSaniflo SaniPLUS - Macerating Upflush Toilet, etc... Very close to framing in her side.I am sorry for going off topic here. I want to respect the forum & it's members.I will start a new topic when I start to build the room. I have been accumulating more electronic parts & tube amps from vintage organs headed for the dump.Thank you for your help.

author: ez24
author_rank: Super Contributor
timestamp: January 23, 2017, 07:13:29 pm
content: Quote from: finom1 on January 23, 2017, 04:30:41 pmHow do you like this? I was going to get one but they do not like angles and slopes - strange