hybridfree/eevblog-posts huggingface dataset:
Klein MM1000 - Page 1
Forum section: electronics / testgear

author: tony3d
author_rank: Frequent Contributor
timestamp: September 08, 2013, 09:42:24 pm
content: Hi all, anyone here have this meter? Is it decent for about $65.00?

author: retiredcaps
author_rank: Super Contributor
timestamp: September 08, 2013, 10:29:56 pm
content: It likely that the Klein MM1000 is similar, but not identical to the UEI DM391 as shown in Dave's $100 shootout.See this somewhat related thread ...https://www.eevblog.com/forum/testgear/klein-tools-mm2000-multi-meter-review/

author: tony3d
author_rank: Frequent Contributor
timestamp: September 08, 2013, 10:47:11 pm
content: Thanks for the Link.
HP1662A Logic Analyzer - Should i ? - Page 1
Forum section: electronics / testgear

author: bingo600
author_rank: Super Contributor
timestamp: September 08, 2013, 09:02:25 am
content: Guyzz i can get a HP1662A Logic Analyzer (68 chan), incl cables , pods & grabbers for $200I already have a DigiView DV1-100 (18-chan 100Mhz) , and it's actually quite ok (I don't use it that often)http://web.archive.org/web/20080418073020/http://www.tech-tools.com/dv_dv1.htmAs i read it the HP only has 4K mem/chan , it's quite big (L/W/H - 367/440/205 mm) , and there is a pict of a bit fan behind.Pros: Standalone , all pods/grabbers included.Cons: Big , FannoiseI don't have that much tablespace in the lab , and i'm worried about where to place it , and cable lengths (shelf).I'm 99% sure that if i'ts not "ready to connect" , i will not use it.I can also get a HP Agilent 1660CS (168 chans) incl. 2 x 250Mhz Scope for $650 , haven't found size or fannoise yet.This one might get place where my TDS-320 is , but i really don't need another scope.So that should be because i can combine the scope & LA channels ....Basicly i'm talking my self out of it , but the $200 price for the HP1662A is dragging ....Just the 68-Grabbers are nice .....Please talk me out of it (or ....)Ps: Anyone know the fannoise level of the HP1662A , ie. the wife thinks my 6632B fans areLOUD./Bingo

author: PA0PBZ
author_rank: Super Contributor
timestamp: September 08, 2013, 09:24:43 am
content: I have been looking at these (ancient) stand alone LA's myself, but as you say there are too many cons: size, weight, noise and the fact that you don't use it that often. If you already have a PC in the lab then go for a box like you already have.Anyway, that is how I talked myself out of getting one.

author: DRT
author_rank: Regular Contributor
timestamp: September 08, 2013, 10:01:43 am
content: I've got the HP1660A (136 channel version). It is fairly noisy, doesn't have any protocol decoders, and I don't use it very often, but the multi-step triggering capabilities are fantastic. I'm considering selling mine, but only because the deep memory on my DSO lessens the need for the advanced triggering.

author: bingo600
author_rank: Super Contributor
timestamp: September 08, 2013, 11:36:29 am
content: Thanx guyz :-)So far it's 2 - 0 to the Don't team.I'm dropping it .....I ended up with 2 x TTi pl154 PSU's instead for 100€No fans , and quite accurate./Bingo

author: PA0PBZ
author_rank: Super Contributor
timestamp: September 08, 2013, 02:19:20 pm
content: Quote from: bingo600 on September 08, 2013, 11:36:29 amYou just had to spend the money didn't you?

author: bingo600
author_rank: Super Contributor
timestamp: September 08, 2013, 02:28:23 pm
content: Quote from: PA0PBZ on September 08, 2013, 02:19:20 pmYupp ... I felt cheated out of a "treat" ...There ought to be a PreReq. of min. 100m2 labspace , before one gets allowed to read this forum.I haven't gotten the room for the things i read about here/Bingo
Are Metex and Unisource the Same Company?  - Page 1
Forum section: electronics / testgear

author: Dawn
author_rank: Regular Contributor
timestamp: September 07, 2013, 11:34:16 pm
content: For a while, many of metex's product line was carring the same model numbers or a slightly different eg. MS-9150 vs US-9150 by Unisource, but the products were the same. Metex's page seems to be an orphan now with Unisource's page up to date, but Metex products are still apearing with that name. Tech support at MCM told me the Metex had gone out of business and the reason they dropped their re-labled products a few years ago. They don't respond to any e-mails, while Unisource has a US rep contact you, but can only forward back any questions and apparently can arrange to provide Metex parts at a king's ransom sent from Korea. Does anyone know what's the story here? Is Unisource just a distributor with their own brand name or are they now what's left or the same as Metex?

author: Hydrawerk
author_rank: Super Contributor
timestamp: September 08, 2013, 12:45:57 am
content: The web is still running.http://www.metex.co.kr/Someone has to pay the webhosting. But the web looks like if it was abandoned in 2003 or so.
Oscilloscope calibration - Page 1
Forum section: electronics / testgear

author: EddieC
author_rank: Newbie
timestamp: September 06, 2013, 01:49:55 pm
content: Hi,My oscilloscope was a bit off on the horizontal axis, so I decided to open it and calibrate it. Everything went well, but at the beginning I moved by mistake a pot marked as "10msDIV"; the problem is, I couldn't put it back on its original position because it doesn't seem to do anything that I can see on the screen.Anyone knows what this "10msDIV" pot is for?Thanks

author: Unknown
author_rank: Unknown
timestamp: September 06, 2013, 01:54:38 pm
content: I would guess it's to calibrate the 10ms/div timebase settings. But how about posting the information that people need to answer your question, like the model of the scope in question and if available a link to the service manual or schematic?

author: EddieC
author_rank: Newbie
timestamp: September 06, 2013, 02:03:57 pm
content: Quote from: alm on September 06, 2013, 01:54:38 pmThanks alm,It's an Hitachi V-522 and this is the link to the manual with the schematic:http://skory.z-net.hu/alkatresz/hitachi_v-522-v-523-v-525_service_m.pdfDo you know why I can't see any changes on the screen when I move the "10msDIV" pot; is this normal? I thought that pot would change the timebase, but I had to move the "H. gain" pot instead.

author: Unknown
author_rank: Unknown
timestamp: September 06, 2013, 02:20:35 pm
content: I'm not familiar with this particular scope, and the manual doesn't have proper adjustment instructions. From the schematic it looks to me like the 10 ms/div trimmer (RV542 on page 55 (52) of the PDF) would have the most effect with the var sweep control rotated fully counter clockwise, so it may be an adjustment for the variable sweep.

author: EddieC
author_rank: Newbie
timestamp: September 06, 2013, 02:43:33 pm
content: Quote from: alm on September 06, 2013, 02:20:35 pmYou are spot on! it changes the speed of the sweep. I couldn't see it before because the timebase was too small. Thanks a lot.Do you also know how should I adjust it? I mean, is there any reference to check if the sweep is adjusted, or is it just a matter of preference?

author: Unknown
author_rank: Unknown
timestamp: September 06, 2013, 02:46:55 pm
content: If it affects the calibrated sweep settings (it should affect it at 5 ms/div and slower), then you should obviously adjust it so the marked sweep speeds are correct. If it only affects the variable control I would probably adjust it so the range is similar to that at 2ms/div and faster sweep speeds, where it would not use this adjustment. The manual claims at least 2.5x slower sweep with the var control fully counter clockwise.

author: EddieC
author_rank: Newbie
timestamp: September 06, 2013, 03:06:35 pm
content: Quote from: alm on September 06, 2013, 02:46:55 pmI see what you mean; it's affecting only the timebase from 5ms/div upwards (that's why I couldn't see it doing anything before), so I'll adjust it as I did with the "H gain" for the fast sweeps.That was really helpful; thanks a lot.
Tektronix TDS 220 question type thing - Page 1
Forum section: electronics / testgear

author: holographicpencil
author_rank: Newbie
timestamp: September 04, 2013, 09:50:44 am
content: Hello there,Im just starting out in electronics and have brought myself a Tektronix TDS 220 second hand. The main question i have is when the probes are hooked up to the calibration circut which is marked as 5v 1khz, the scope calculates that there is closer to 6 volts though the frequency is still 1khz. Im wondering if this is a common issue with oscilloscopes or is mine wierd? is there a need to have it calibrated, does it really matter or is it just possesed and i should set it on fire and dance around it etc?Thanks for your input in advanceJack

author: larry42
author_rank: Regular Contributor
timestamp: September 04, 2013, 09:57:01 am
content: Can you include a screenshot? You might need to adjust the probe compensation screw on the probe. The scope manual should tell you about thisSent from my HTC One S using Tapatalk 2

author: holographicpencil
author_rank: Newbie
timestamp: September 04, 2013, 10:04:35 am
content: thanks for the reply!Unfortunatly the scope is at my weekend hangout so i cant take a picture until then. I have ajusted the probe so it shows a square wave with nice square corners etc. however i would of expected it to put out a voltage really close to the nominal 5v rather than the 5.9 or 6v the scope calculates it at?Jack

author: Unknown
author_rank: Unknown
timestamp: September 04, 2013, 10:50:27 am
content: 6 V sounds quite far off, but note that the probe calibration output is only intended to adjust the probe compensation. It's generally not an accurate reference for either frequency or amplitude. I wouldn't worry about it if amplitude measurements of other known signals are accurate (eg. DC voltage or 50/60 Hz sine from function gen or transformer that you check with your DMM). Note when comparing DMM values and scope readings that the meter indicates the RMS voltage, and the scope often peak-to-peak. I think the TDS-220 supports RMS as one of the automated measurements so you can directly compare the values.

author: larry42
author_rank: Regular Contributor
timestamp: September 06, 2013, 06:34:02 pm
content: If you don't have a function or signal gen, then you can measure a battery voltage (DC) with your scope probe and compare it with a multimeter.NB Most multimeters should be better than 2% accurate, and few scopes are not much better than 3% accurate (though they often do quite well at DC, their 8bit ADCs are built for speed, not accuracy).
Instek GTP-350A-2 Probe question - Page 1
Forum section: electronics / testgear

author: Computeruser
author_rank: Regular Contributor
timestamp: September 06, 2013, 12:58:20 pm
content: I have a GW Instek GDS 2304A oscilloscope and it came with 4 GTP-350A-2 probes.If you have one of these probes, look at the connector end at the connector body. On one side is a hole marked LF and that is how you do standard low frequency compensation.On the other side, there are two white plastic plugs and the designation HF.The Probe Manual says, in part, "HF compensation should seldom require adjustment". It goes on to say that if you need to adjust it, here is the procedure and you use the HF trimmer to adjust.Question: Given what appears to be two fixed white plastic plugs, how would you access the HF trimmer?I do not think I have any need to adjust HF compensation, so the question is one of curiosity for the future.Thanks, .... C
what's wrong with this 87V Fluke ? - Page 1
Forum section: electronics / testgear

author: IvoS
author_rank: Frequent Contributor
timestamp: September 06, 2013, 12:12:12 am
content: Today, out of the blue, I turned my Fluke on and the display seems broken. What can possibly be wrong with the unit? I bought it brand new, it's only 1 1/2 year old. Every time I short the probes, I can see highlighted symbols.

author: Wytnucls
author_rank: Super Contributor
timestamp: September 06, 2013, 12:47:01 am
content: Was it dropped? It looks like the display has shifted a bit. You may need to open the meter and reset the display properly on the zebra connectors.http://mrmodemhead.com/blog/fluke-8x-faded-lcd/

author: saturation
author_rank: Super Contributor
timestamp: September 06, 2013, 06:09:47 pm
content: I concur with Wytnucls, but your unit is still under warranty at 1.5 years old. It is odd behavior for new device. That's a great link for fixing the LCD too for anyone who isn't a take it apart' type, kudos to you.

author: IvoS
author_rank: Frequent Contributor
timestamp: September 06, 2013, 07:44:29 pm
content: No, I didn't drop it. It just happened. One day it was good, other day I turned it ON and that was it. I took it apart just removed those rubber strips then put it back together and it seems better. It's not 100% but it's better then it was, so it might eventually need some cleaning. I have RMA but I think I will wait see what happens.

author: casinada
author_rank: Frequent Contributor
timestamp: September 06, 2013, 09:23:09 pm
content: I would send it back to Fluke. Is still under warranty and when they repair it they probably re calibrate.
LA Advice - Page 1
Forum section: electronics / testgear

author: echen1024
author_rank: Super Contributor
timestamp: September 13, 2013, 01:10:48 am
content: Well, I've been deciding between an Arb gen and a LA, and want some advice on LAs. I would prefer a benchtop unit, so I was looking at the Tek 704 series, which I can get on fleabay for quite a reasonable price ($300), or an Agilent model, which seem to be dirt cheap. I just wanted to which would be preferable, and is there anyhting I should look out for, such as those Dallas ram in a box things.

author: c4757p
author_rank: Super Contributor
timestamp: September 13, 2013, 01:14:46 am
content: "Dallas RAM in a box" - mind if I steal that phrase? I like itWhat kind of things do you want it for? I've found a Zeroplus to be more than sufficient for what I need, at a much lower cost, but of course you might not. (I prefer a bench unit too, but I didn't need one badly enough to justify the cost.) I'd much rather have an arb gen.

author: echen1024
author_rank: Super Contributor
timestamp: September 13, 2013, 02:38:48 am
content: Nah. No problem. Yea, I think an Arb gen might be more helpful, but what for?

author: c4757p
author_rank: Super Contributor
timestamp: September 13, 2013, 02:59:21 am
content: Well, do you spend more time with digital circuits or analog?

author: David_AVD
author_rank: Super Contributor
timestamp: September 13, 2013, 03:10:26 am
content: I have used my Arb Gen twice, but used my LA many times !

author: echen1024
author_rank: Super Contributor
timestamp: September 13, 2013, 03:17:37 am
content: Quote from: c4757p on September 13, 2013, 02:59:21 amI mainly do digital.

author: TerraHertz
author_rank: Super Contributor
timestamp: September 13, 2013, 03:41:25 am
content: Being in the USA, so not having to pay more for shipping than you paid for the equipment, why not aim to get both a LA & Arb?I'd have bought a 7xx series LA, giving access to the huge range of plugin modules, if I could afford it. But there are lots of other things I want too, and I'm trying to keep spending down. Also the TLA614 I got came with all the probes, which LA's on ebay usually don't. So then you have to hunt and pay for them too, and they are not cheap.Speaking of arbitrary function generators, I'm so tempted by this:http://www.ebay.com/itm/300694263268?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649Assuming the busted SMA connectors are replaceable, and not an inseparable part of some unobtainium gold-plated internal brick.
Equipment for injecting common mode noise?  - Page 1
Forum section: electronics / testgear

author: BiOzZ
author_rank: Regular Contributor
timestamp: September 04, 2013, 07:57:31 pm
content: im looking for a piece of equipment i can either buy or make my self that injects common mode noise on to a 60hz 110-120v line for work (power supply designing) but it MUST use an actual sine wave (not like a 4 step, square wave or whatever to make it as real as possible) and it CANNOT inject it down the line because we have other sensitive equipment in the lab and just one 110 and one 220 lineEDIT: oh i need some sort of rough adjustment to see worse and best case scenariosthanks!

author: macboy
author_rank: Super Contributor
timestamp: September 05, 2013, 06:45:39 pm
content: How about using a 120V-120V isolation transformer. The secondary will be floating. To introduce common mode noise, connect a suitable noise signal generator between the "low" side of the secondary and ground. You now have common mode noise w.r.t. ground. "Suitable noise signal generator" is up to you.This should not cause much, if any, noise to be injected back to the source. In any case, you can use a power line filter to help isolate noise in both directions (from and back to the source).

author: Unknown
author_rank: Unknown
timestamp: September 05, 2013, 07:01:55 pm
content: The signal generator needs to drive the fairly substantial capacitance to ground though. You might need a fairly beefy signal generator or amplifier.
Kenwood CS-6030 oscilloscope, . . need a manual for this...  - Page 1
Forum section: electronics / testgear

author: julius22
author_rank: Newbie
timestamp: September 04, 2013, 01:35:41 pm
content: Hello, I just joined this forum...I have a Kenwood CS-6030 oscilloscope, which I liked and used a lot.But one day there was this smoke coming from it!Does someone have a service manual for this scope?And it would be great to have a user manual, if I get it working, because the date on the display always was out of time.RegardsJulius
Agilent N2772A 20 MHz Sonde diffentielle - Page 1
Forum section: electronics / testgear

author: eurofox
author_rank: Unknown
timestamp: August 25, 2013, 09:07:35 pm
content: Hi,Hurry I got minehttp://www.benl.ebay.be/itm/Agilent-N2772A-20-MHz-Sonde-diffentielle-/221272140925?pt=FR_YO_MaisonJardin_Bricolage_ElectroniqueComposants&hash=item3384d8ec7d&_uhb=1Eurofox

author: Unknown
author_rank: Unknown
timestamp: August 25, 2013, 09:43:14 pm
content: Snagged up the second one, thanks. €110 for a HV diff probe is a steal in my opinion.

author: eurofox
author_rank: Unknown
timestamp: August 25, 2013, 09:58:05 pm
content: Quote from: alm on August 25, 2013, 09:43:14 pmThat is the reason why I post it, there was one left and it is specified working, I check on eBay US $$$-$$$$ so nice tool added to my bench oscilloscopeEurofox

author: eurofox
author_rank: Unknown
timestamp: September 03, 2013, 06:10:50 pm
content: Arrived todayis just like new, no sign of use, test and work perfecteurofox
Electronic Load - Trap for new players - Page 1
Forum section: electronics / testgear

author: Mike Warren
author_rank: Unknown
timestamp: September 04, 2013, 11:11:38 pm
content: This cost me a few minutes yesterday, wondering why the turn-on of my MOSFET at 1 amp was so odd.First picture is when using the electronic load and the second is with a resistor.

author: kizzap
author_rank: Unknown
timestamp: September 05, 2013, 01:14:48 am
content: Care to explain what was happening?-kizzap

author: crisr
author_rank: Contributor
timestamp: September 05, 2013, 01:57:12 am
content: What's channel 1 and what's channel 2? I assume the e-load was used in constant current mode, since you said that the test was @ 1A; have you tried it in constant resistance, since you are comparing it to a resistor? And what brand / model of e-load was it?

author: uoficowboy
author_rank: Regular Contributor
timestamp: September 05, 2013, 03:46:28 am
content: Quote from: crisr on September 05, 2013, 01:57:12 amWe have a BK Precision 8500 at work and I can say that it acts really strangely in constant resistance mode. I think it might be a digital control loop, not an analog one. So you get funny looking behavior (similar, but not the same, as this) when in constant R mode. Constant I mode tends to work well though.

author: Mike Warren
author_rank: Unknown
timestamp: September 05, 2013, 06:42:48 am
content: Quote from: crisr on September 05, 2013, 01:57:12 amThe blue channel is not relevant. It's just a signal feeding a voltage booster for the MOSFET gate. I was looking at it to see if it had any bearing on the distorted turn-on of the MOSFET. It didn't.The load is a REK RK8511. It does pretty much the same thing in CR mode. I'd expect all these common loads (Maynyuo, B&K) to behave the same since they seem t all be based on the same design.
Multimeter giving random results - Page 1
Forum section: electronics / testgear

author: netdudeuk
author_rank: Frequent Contributor
timestamp: September 02, 2013, 10:31:35 pm
content: HiI've just got a load of 1% 1/4 watt resistors and was comparing the bands with what my DMM was showing. Most 'strips' are ok but some of them have resistors which are way off the mark, like fifty percent. I've scraped the wires to get better connections and replaced the battery but things are the same. Also, the resistance reading would be constantly changing by a small amountAny ideas please ?Thanks

author: karlmag
author_rank: Contributor
timestamp: September 02, 2013, 10:48:56 pm
content: Hi,Bad quality resistors and/or wrongly labled ones?I know it has happened.Guess it might depend on if it's a reputable shop and if it's brand- or noname resistors too.

author: Unknown
author_rank: Unknown
timestamp: September 02, 2013, 10:51:16 pm
content: Your DMM is unlikely to give stable values that are 50% off if you connect it to some resistors but not to others. If it's consistently off for the same resistors, then I would say you've got a bad batch of resistors. You sure it's not a red band that looks brown or something silly?I know some Chinese vendors will paint carbon film resistors blue with a brown tolerance ring and sell them as 1% metal film. Did they start relabeling 1k resistors as 2k now?

author: netdudeuk
author_rank: Frequent Contributor
timestamp: September 02, 2013, 11:01:45 pm
content: Quick responses thanks guys.I got them from China and they are indeed blue with a brown tolerance ring and advertised as 1% metal film.I'm ok with the colours but I did wonder at first how you were meant to know which way round some of them were as they looked tangible either way.Maybe I ought to check every resistor before I use it.

author: tszaboo
author_rank: Super Contributor
timestamp: September 02, 2013, 11:14:59 pm
content: Oh, China, that explains a lot. I think it is probably cheaper if you buy some Welwyn, Bourns, or Vishay. Time is money.
Which Logic Analyzer to Buy?? (1650a or Logic Sniffer?) - Page 1
Forum section: electronics / testgear

author: whitnasty1
author_rank: Newbie
timestamp: September 03, 2013, 02:03:31 am
content: Question answered. Thanks.

author: marshallh
author_rank: Unknown
timestamp: September 03, 2013, 03:09:17 am
content: You mention you're building a relatively modern digital system and you don't know what you need to stick an LA on?If you wanted to debug any one of those subsystems you'd be looking at tens of thousands of $$$...And then design the PCB so that you can actually tap lines without crashing anything.Are you debugging 64bit 500mhz source synchronous busses? or just SPI and i2c? That complete changes things.High speed serdes-based protocols like PCIe, SATA, USB et al are not things you can put a traditional logic analyzer on... you will need a dedicated analyzer for that protocol, or a 5ghz bandwidth scope with protocol decoding ($$$$$$).I would pick the HP over the open sores sniffer.. but that said, both are pretty crap.Look up the Intronix Logicport.It seems like you don't know what you need, so before you go buy stuff, do simple things like sticking a serial console on there with printf's or something like that.

author: c4757p
author_rank: Super Contributor
timestamp: September 03, 2013, 03:16:05 am
content: Quote from: whitnasty1 on September 03, 2013, 02:03:31 amQuoteEither this is a joke, or you've bitten offwaymore than you can chew. Best to spit it out...

author: echen1024
author_rank: Super Contributor
timestamp: September 03, 2013, 03:29:52 am
content: Eh. 3GHz+. Sort of bitten off more than you can chew. But if you're devoting time to this type of project, a new Agilent 68 channel LA might be the way to go.

author: Skimask
author_rank: Super Contributor
timestamp: September 03, 2013, 03:34:48 am
content: http://forum.grasscity.com/bongs-bubblers-water-pipes/1215775-can-i-use-smaller-downstem-45-instead-475.html

author: Unknown
author_rank: Unknown
timestamp: September 03, 2013, 03:37:22 am
content: http://www.ebay.com/sch/i.html?_trksid=p2047675.m570.l1313.TR0.TRC0&_nkw=Instek+GLA&_sacat=0&_from=R40http://www.tequipment.net/InstekGLA-1132.htmlhttp://www.tequipment.net/JanatekLA-GOLD-36.htmlhttp://www.tequipment.net/LinkInstrumentsLA-55160.htmlor a Mixed Signal Oscilloscope.

author: synapsis
author_rank: Regular Contributor
timestamp: September 03, 2013, 04:06:37 am
content: I have an HP 1663A that I'll sell for $200 + shipping (what I paid for it.) 500Mhz/250Mhz 16/32 channel timing or 100 Mhz 32 channel state.Everything works. Took it apart and cleaned it. Also have PDFs of all the manuals.
Need: Tektronix CPS-250 Calibration Procedure - Page 1
Forum section: electronics / testgear

author: radiotek
author_rank: Contributor
timestamp: August 30, 2013, 03:31:25 pm
content: Even though this was a lower priced power supply that was manufactured by Tektronix it was still a very was designed and well built power supply. I opened it up and it saw that it was extremely well made and had high quality components thoughout. It also has a very large heavy duty power transformer that looks like it could handle 10 or more amps. This power supply also has a very complex circuit with 13 adjustments pots for performing a precision calibration. If anyone has the schematic or calibration info it would be greatly appreciated.
PPM LTD Model 410/411 Voltage Reference - Page 1
Forum section: electronics / testgear

author: TonyGreene
author_rank: Contributor
timestamp: August 31, 2013, 04:38:15 pm
content: I am looking for any information on a PPM LTD (England) Model 410/411 Voltage reference.The box is one rack unit high for a 19 inch rack. On the rear it has female banana jack showing a zener at 6.25498 volts. It has 1000 and 100 volt inputs to a divider that outputs 1 volt. It has 10V, 1V, 100mV, 10mV, 8mV, 6mV, 4mV, 2mV, 1mV and 0 volt outputs, along with a guard and sense banana jacks.This unit shows it was calibrated last September 1987. A transformer inside shows a built date of 1979. The unit uses 0.005 percent green wirewound resistors and the older "TO" can style op amps that are OP07.The unit used 14 "C" cell nicads, which 2 cells supplied a negative voltage, and the remaining 12 cells supplied a positive power supply voltage.Thanks
DC electronic load opinion - Page 1
Forum section: electronics / testgear

author: israel
author_rank: Contributor
timestamp: August 30, 2013, 11:40:09 pm
content: Hi, I have the opportunity to acquire this dc load at good pricehttp://www.gwinstek.com/en/product/productdetail.aspx?pid=38&mid=78&id=186they think of it?any experience with this model?manual:http://www.testequipmentdepot.com/instek/pdf/pel300_manu.pdfRegards,
Array DC load battery discharge software? - Page 1
Forum section: electronics / testgear

author: nctnico
author_rank: Super Contributor
timestamp: August 30, 2013, 07:37:41 pm
content: Does anyone know if there is better software to discharge a battery using an Array DC load? The software from Array is pretty crappy. It doesn't switch off below the minimum voltage!

author: saturation
author_rank: Super Contributor
timestamp: August 30, 2013, 08:26:03 pm
content: I've been using the DISCHARGE one, its crappy but it works for data acquisition. I manually set Vmin via the keyboard. I've been burn testing and cycling NiMH battery packs for days at the rated max loads of 150W and my 3710a doesn't even get hot, warm at worst. Good thermal design and component choices for whomever designed it. The compact case makes it very easy to transport. I wish I had time to write new software.http://www.array.sh/yqxzcnE.htm

author: nctnico
author_rank: Super Contributor
timestamp: August 30, 2013, 09:02:10 pm
content: Well I can't get it to work. Yet another crappy piece of software written in Delphi...
Tenma 72-905 Manual? - Page 1
Forum section: electronics / testgear

author: millerjs
author_rank: Newbie
timestamp: August 26, 2013, 11:30:41 pm
content: Hi all!I have recently acquired a Tenma 72-905. It seems to be a pretty standard 20MHz analog scope, but I'd really like to have a manual for it. Unfortunately I've not been able to find one online, so I thought I'd start asking around to see if anyone has one! I've emailed MCM Electronics (current owners of the Tenma name, I think?) but I'm not banking on getting a response.Thanks in advance!John

author: millerjs
author_rank: Newbie
timestamp: August 28, 2013, 08:51:46 pm
content: An update: the guys from MCM got back to me and sent me a scanned copy of the manual.I've put it in my public dropbox folder if anyone else wants a copy:https://dl.dropboxusercontent.com/u/9147276/Tenma_72-905_manual.pdf
Spectrum Analyzer specs, RBW and filter shape - Page 1
Forum section: electronics / testgear

author: Alexei.Polkhanov
author_rank: Frequent Contributor
timestamp: August 28, 2013, 06:41:56 pm
content: In my previous post I had a question about Tracking Generator in Spectrum Analyzers. I think this is somewhat unrelated question so I decided to create new topic.I was looking at spec sheets for different spectrum analyzers and I found myself in a usual deadlock - same parameter described in different terms by different manufacturers. I am talking about Agilent, Anritsu and R&S.Most of specs have value for RBW, but Agilent provides value for "resolution filter shape" in form of a ratio. For example they explain that if minimal RBW is 3Hz then 15:1 ratio for resolution shape means that I will have a 45Hz resolution for signal 60db down. I understand that 5:1 mens better resolution. (will result in 15kHz in this case). Example of spec that provides this value:http://cp.literature.agilent.com/litweb/pdf/5990-5587EN.pdf. When I looked at one of Anritsu SA spec sheets I found nothing that resembles such parameter. For example this manual:http://www.anritsu.com/en-GB/Downloads/Manuals/User-Guide/DWL1922.aspxshows minimal RBW 10Hz but nothings regarding the filter shape.Well 10Hz probably is not as good as 3Hz but still I am wondering if there is any way to derive filter shape parameters from Second Harmonic Distortion or other available value?
HP 5245L Counter: Reading 20% too high - Page 1
Forum section: electronics / testgear

author: valvedoctor
author_rank: Contributor
timestamp: August 28, 2013, 03:53:39 pm
content: Hi everyone,I recently got this counter on eBay for little over 100 bucks CND with shipping. Since I'm a tube nerd, I just couldn't pass on the nixie tube display. Everything seems to work correctly, but the reading are about 20% too high.Note, that I'm a tube guy and strictly analog in all my work, so I may need some assistance from fellow members on calibrating this unit.Any suggestions?

author: Unknown
author_rank: Unknown
timestamp: August 28, 2013, 04:23:09 pm
content: 20% high doesn't sound like a calibration issue to me. I'm not familiar with this instrument, but I would start by checking the voltage rails for both level and ripple. You will probably be able to find a scan of the service manual if it didn't come with one on either theAgilent website, theBAMAandKO4BBmanual sites or from commercial sellersArtek ManualsandQservice.

author: Rufus
author_rank: Super Contributor
timestamp: August 28, 2013, 05:31:08 pm
content: Quote from: valvedoctor on August 28, 2013, 03:53:39 pmKO4BB has a service manual.A stable signal generator would be helpful to diagnose. If it is 25% high one of the decade counters might be dividing by 8 instead of 10. In that case one of the digits won't go above 7.

author: Clint
author_rank: Regular Contributor
timestamp: August 28, 2013, 05:41:20 pm
content: What a lovely piece of kit !!!!

author: valvedoctor
author_rank: Contributor
timestamp: August 28, 2013, 06:47:41 pm
content: Thanks for replies. I do have the pdf manual from the site you provided.As for a stable signal generator, I have an HP 456A sine generator up to 50mHz which is bang on. I also have a HP 5315A frequency counter, also bang on. As you can tell, I like my HP gear!I haven't bothered to check the rear signal port on the back, directly from the crystal oscillator, but will do so and let you know.I will check it out, and also I will sweep some frequencies to make sure all numbers are appearing on the decades.Thanks again.
Extech 380820 can't do rated power - Page 1
Forum section: electronics / testgear

author: Phaedrus
author_rank: Frequent Contributor
timestamp: August 26, 2013, 10:38:05 pm
content: We use an Extech 380820 power analyzer for efficiency and PFC measurements in our power supply test lab. It's been nothing but trouble.It failed on us about a month ago when we tested a power supply that failed shorted. The analyzer lost all display on its front panel, but still showed voltage on its 115VAC pass-thru outlet. Fuse checked good. Sent it in for repair. It took two weeks to get it back; when we did the repair notes simply said "regular maintenance". It worked fine though.Skip to today. I was testing a 1300W power supply at 1230W load, AC draw around 1450VA. Keep in mind this analyzer is rated for 2kVA. I shut the PSU off to attach an additional cable to reduce output voltage drop. The unit refused to turn back on. After troubleshooting a bit, I found the failure point: the Extech power analyzer, which had the same no display condition, but also now refused to conduct on the AC pass-thru! I disassembled it, tested the fuse OK, and found no obvious damage.Why did this piece of crap fail over 500VA below its rating? Why does it not have user-replaceable output protection fuses to protect it from shorts? Why, in short, does it keep failing under conditions that every other power meter I've worked with just shrugs off?

author: envisionelec
author_rank: Frequent Contributor
timestamp: August 27, 2013, 11:41:14 pm
content: According to the manual, it's 1100VA at 110V input and 2kVA at 220V input.

author: TerminalJack505
author_rank: Super Contributor
timestamp: August 28, 2013, 12:07:14 am
content: Doh! Sounds like one of those error code ID 10T issues. I've had plenty of those.
Funny multimeter on ebay, maybe good for teardown? - Page 1
Forum section: electronics / testgear

author: Tooms
author_rank: Unknown
timestamp: August 27, 2013, 04:08:57 pm
content: http://www.ebay.co.uk/itm/Vintage-Multimeter-Model-TSm-Hansen-Made-in-Japan-/281158017551?pt=AU_B_I_Electrical_Test_Equipment&hash=item417652e20f#ht_368wt_1399maybe for a teardown?

author: ben_r_
author_rank: Frequent Contributor
timestamp: August 27, 2013, 04:31:43 pm
content: That is a weird looking one. Buy it and send it to Dave!

author: Tooms
author_rank: Unknown
timestamp: August 27, 2013, 04:35:17 pm
content: The item is located at "Vermont , Melbourne, Victoria, Australia" so it is smarter if someone local to Dave or the man him self can do it.Tooms

author: eurofox
author_rank: Unknown
timestamp: August 27, 2013, 06:44:16 pm
content: Quote from: ben_r_ on August 27, 2013, 04:31:43 pmVery very long time ago I got one like thateurofox

author: Blaffetuur
author_rank: Regular Contributor
timestamp: August 27, 2013, 07:19:15 pm
content: Yeah if someone could make this happen
Curve Tracer with a DSO? - Page 1
Forum section: electronics / testgear

author: Unknown
author_rank: Unknown
timestamp: August 27, 2013, 10:21:04 pm
content: just wondering if there is a way to make a curve tracer with a DSO?something like Tektronix Model 576, but not old, not cathode tube.

author: TerminalJack505
author_rank: Super Contributor
timestamp: August 27, 2013, 11:47:05 pm
content: Read this thread:https://www.eevblog.com/forum/beginners/dirt-cheap-and-simple-scope-based-component-tester-curve-tracer/Somewhere in it, someone posted a schematic and a magazine article of a transistor curve tracer.This post, I think.Should work with a DSO scope so long as it has an X-Y mode.

author: mcinque
author_rank: Unknown
timestamp: August 28, 2013, 01:45:32 pm
content: Yes, it's indeed a cheap ad useful device, and it's very simple.Take a look a the w2aew schematic that I've freely redesigned, grab a couple of bnc, a resistor and a transformer, and you're done!

author: Unknown
author_rank: Unknown
timestamp: August 28, 2013, 01:57:55 pm
content: That's not really a curve trace, but more of a basic Huntron tracker tool typically used for troubleshooting. It's fine for qualitative measurements, but accurate quantitative measurements like current gain, for example to test unknown transistors or to match them, will be tricky if not impossible.

author: TerminalJack505
author_rank: Super Contributor
timestamp: August 28, 2013, 06:26:29 pm
content: Quote from: alm on August 28, 2013, 01:57:55 pmYeah, I wouldn't expect much for what basically amounts to $10 to $20 in parts.Both the octopus tracer and transistor tracer are on my "build, just for fun" list.

author: jancumps
author_rank: Unknown
timestamp: August 28, 2013, 06:44:44 pm
content: Are you looking for a Bode plot on the scope?

author: jancumps
author_rank: Unknown
timestamp: August 28, 2013, 06:46:45 pm
content: Or this type of tracer:

author: Unknown
author_rank: Unknown
timestamp: August 28, 2013, 06:55:15 pm
content: The latter, given that he references the Tek 576.

author: jancumps
author_rank: Unknown
timestamp: August 28, 2013, 07:03:48 pm
content: So that's possible. The photo is taken from my DSOi used this schema fromhttp://www.intio.or.jp/jf10zl/trct.htmWorks only for NPNs.
E3631A PSU Issues - Page 1
Forum section: electronics / testgear

author: microwave68
author_rank: Newbie
timestamp: August 25, 2013, 11:35:51 pm
content: I have a E3631A that I was using without problems for the last 2 years, now the supply developed some issues !The output voltages on all 3 output terminals are present and adjustable but the display reads 0.00V and 0.00A, there is no indication of current even if I draw a current !I got the manual with schematics but somehow this whole ADC block is rather confusing to me , I changed the 74HC4053 as well as the OP27 and AD711 In the ADC circuitry and checked all the voltage supplies but it still does not work !Anyone ever experienced similar issues with this PSU ? the top board is not available from Agilent and the exchange price for the whole unit is $450 !

author: free_electron
author_rank: Super Contributor
timestamp: August 26, 2013, 04:58:19 am
content: if you measure at the input of the 4053 : do you see the return signals ?replace the ad706 in the adc.that whole adc is a charge balancer. you can't measure anything in there as everything happens in current domain....
Super fast scope - Page 1
Forum section: electronics / testgear

author: PA4TIM
author_rank: Super Contributor
timestamp: August 26, 2013, 06:57:15 pm
content: My latest scope. (a hell of a lot cheaper as 19 dollar )This beauty is made in 1961 and is a mix of transistors and tubes. It is dual trace (not dual beam) has ballanced inputs and can be used with a differential input. Very modern is a autotruigger postition. It does 10mV/div upto 100V/div (eat this modern DSO)It is build like a tank, it has a build in calibrator that you switch internal to the inputs and has a breathtaking bandwidth of 200 kHz but it is beautifull.More pictures and specs:http://www.pa4tim.nl/?p=4635

author: w2aew
author_rank: Super Contributor
timestamp: August 26, 2013, 07:39:12 pm
content: I like it! Reminds me of my first scope - an Allen B Dumont Cathode Ray Oscillograph, Model 304AR. It also had banana jacks for the vertical (and horizontal) inputs, and probably about the same BW.

author: dr.diesel
author_rank: Super Contributor
timestamp: August 26, 2013, 07:58:17 pm
content: I just finished up working on this pair myself!Heathkit Model IG-18knight KG-630 (mid/late 60s vintage)

author: Unknown
author_rank: Unknown
timestamp: August 26, 2013, 09:01:36 pm
content: Back when you could still use binding posts to connect to the scope. Probes? Who needs probes at audio frequencies? And I guess you don't need attenuating probes either with 100 V/div. 10 mV/div is not so great though, although I think high vertical sensitivities were still quite rare in those days.
tek scope calibration 465 B  and full book hardcopy. - Page 1
Forum section: electronics / testgear

author: endzone
author_rank: Newbie
timestamp: August 25, 2013, 05:37:05 pm
content: Calibration 465.I get to the trigger portion of the book. chapter 6 ,page 24and the lack of SG503,rack/power pack.etc. $$$my weak generartor is 100mv across 50ohm and not 300mv as needed.Question: does any one make sig gen booster. ?i think that works out to 0DBM @50ohms.thanks. for any tips.i may try a USB AD9854 based solution, but the sellers all have weak spec out's on their boards.

author: rastro
author_rank: Frequent Contributor
timestamp: August 25, 2013, 06:24:34 pm
content: You may want to consider a monolithic amp from mini circuits. I'm currently experimenting with an ERA-5SM but they make other similar devices. I bought 6 on e-bay for about $9.00US. They are typically made to run at 50-ohm impedance. I'm running one with input using cheap ebay DDS AD9850 and getting on the output 0.725V(pkpk) @ 10MHz. The ERA-5SM is bias with 9VDC and 68-ohm bias resistor - draws 65mA. Not a high power device but should provide buffered signal @ 50 ohms.

author: endzone
author_rank: Newbie
timestamp: August 25, 2013, 07:09:57 pm
content: thanks, perfect, even the ERA-6 would work.so simple.id only need to pad it down...any one make PCB kits/ for this chip, with BNC in and out or TNCthanks. very much !

author: rastro
author_rank: Frequent Contributor
timestamp: August 25, 2013, 07:24:15 pm
content: I don't know what frequency you're working at but you could try dead-bug connections and mini-grabbers to your test circuit. Probably not pretty but might get you over the hump.

author: endzone
author_rank: Newbie
timestamp: August 25, 2013, 10:41:09 pm
content: sorry i failed that. yes,,,, and agree. (dead dogs and sky circuits, done them all, not pretty, but may be my last scope cal ever....)yes, 25mhz. 50 then 100mhz , pure sine waveat 0dbm 300mv. max. in to 50 ohm scope jack terminators.my guess is to take double sided PC, and drimmel the lines , like we did in our prototype labs in the 80s.wed cut the traces by hand.i saw many cards for sale for every chip they make but not this simple amp... that would be so cool... maybe this winter ill lay one out , for fun.cheers and thanks.
Ballantine Labs 3205B Micro-Ohmmeter - Page 1
Forum section: electronics / testgear

author: ketil b
author_rank: Regular Contributor
timestamp: August 24, 2013, 06:53:28 am
content: Hi allI been lurking hear for awhile now.Any how I have a chance to buy a Ballantine Labs 3205B Micro-Ohmmeter for a good price.But I cant find much info on it, just the web sitehttp://www.ballantinelabs.com/3205b.htmDoes any one have any experience of this meter or a copy of the manual.ThanksKetil

author: robrenz
author_rank: Super Contributor
timestamp: August 25, 2013, 04:04:47 am
content: Welcome to the forum!It is concerning that there is no mention in the specs about thermal emf cancellation either by offset compensated ohms or current reversal techniques. 4 wire alone is not enough at micro ohm levels. If you cant verify that it has some form of thermal emf compensation I would recommend staying away from it. The accuracy specs are fairly good but there are more accurate micro ohm meters out there if it matters to you. Also concerning that the manual is not accessible from their site.

author: ketil b
author_rank: Regular Contributor
timestamp: August 25, 2013, 09:28:45 am
content: Thanks that helps a lot. I was hoping that some would say its similar to the Cambridge Technology / IET 510.I will just keep an eye out for a "for parts" keithley 580.ThanksKetil

author: robrenz
author_rank: Super Contributor
timestamp: August 25, 2013, 07:54:33 pm
content: I have 2 of the IET/Cambridge tech 510A. Very excellent performing unit and far superior accuracy and resolution to the keithley 580 as long as you don't need a computer interface. My thread on the 2 unitshereOne on ebayherefor $95.00. looks like it is probably functioning even though it says for parts only. Very simple unit internally and should be easy to fix if it isn't working.
Agilent U8002A off state output impedance - Page 1
Forum section: electronics / testgear

author: Aluminio
author_rank: Newbie
timestamp: August 25, 2013, 05:14:14 am
content: Hi all,I have a couple of this power supplies, and are driving me crazy. When the power supply is ON, but the output is dissabled, the impedance between + and - binding posts goes to about 5 ohms shorting the circuit it powers. This impedance with the power supply fully turned off goes to 1k ohm. Its the over voltage protection circuit (crowbar) that shorts the output, but its behaviour is by design.Does anybody know if this happens in the new Rigol 832 supplies?Regards
Rigol DS1052 Power Switch - Page 1
Forum section: electronics / testgear

author: dexters_lab
author_rank: Unknown
timestamp: August 04, 2013, 11:15:46 am
content: I broke the power switch on my rigol ds1052 the other week, this is the actual R/A PCB mount switch on the PSU board.I'm sure i have seen these switches used elsewhere on other products so i'm sure it should be common and should be able to source one but i'm damd if i can find an equivalent with farnell or rs.Does anyone know of a direct replacement?

author: ttp
author_rank: Regular Contributor
timestamp: August 04, 2013, 11:36:12 am
content: Long time ago I broke the power switch too. I couldn't find a replacement but super glue worked wonders, it's still fine after 4 years or so.

author: dexters_lab
author_rank: Unknown
timestamp: August 24, 2013, 05:09:52 pm
content: ok, had this apart today and fixed, the switch is a bit sticky now but least it works.The white plastic had broken in half, i used CA glue to fix.

author: Hydrawerk
author_rank: Super Contributor
timestamp: August 24, 2013, 06:31:47 pm
content: Does this happen even on Agilent or Tek scopes?

author: dexters_lab
author_rank: Unknown
timestamp: August 24, 2013, 07:46:49 pm
content: guess it depends if you take them apart badly as welli broke it when i took the cover off and forgot to remove the button first

author: PA4TIM
author_rank: Super Contributor
timestamp: August 24, 2013, 08:04:11 pm
content: Instead of trowing my DS1102 out of the window I gave it to a student.. Later I heard the powerbutton also died. (while I had it one button stopped function half of the time and an other just deintegrated. Very flimsy made of very thin plastic) Not a good bang for bucks, just expensive crap (I bought it not long after the introduction not knowing Rigol could sell it fot half that price too)