hybridfree/eevblog-posts huggingface dataset:
Best sub-£50 meter with really good continuity - Page 1
Forum section: electronics / testgear

author: cybergibbons
author_rank: Frequent Contributor
timestamp: December 04, 2017, 12:04:45 pm
content: I'm looking for a meter that is available in the UK without having to wait weeks for a Chinese shipment, as I am recommending it for others to buy.It's for hardware reverse engineering, so by far the biggest requirement is a good continuity buzzer, and ideally comes with decent probes.Any recommendations?

author: tautech
author_rank: Super Contributor
timestamp: December 04, 2017, 11:14:08 pm
content: For continuity, check out data that Joe has put together on meters.He found one sooooo fast it could play Van Halen while in continuity mode.https://www.eevblog.com/forum/testgear/hear-kitty-kitty-kitty-nope-not-that-kind-of-cat/

author: rhb
author_rank: Super Contributor
timestamp: December 04, 2017, 11:22:00 pm
content: Mount a DPDT slide switch on the side of the case and add a small piezo sounder.

author: rsjsouza
author_rank: Super Contributor
timestamp: December 05, 2017, 02:31:02 am
content: The UT136 Family is very well built, compact and has a lightning continuity tester. I have a UT136C (with temperature) bought for US$19.00.Actually, 14 pounds at Amazon:https://www.amazon.co.uk/UT136C-Handheld-Auto-ranging-Digital-Multimeter/dp/B06WGRB1VV

author: joeqsmith
author_rank: Super Contributor
timestamp: December 05, 2017, 02:58:24 am
content: How loud do you want it, how fast, latching.... Really depends on what you personally like. This is why when I test them, I don't just touch the leads together and call it a day. I want to know the thresholds, open circuit voltages, short circuit currents.Quote from: tautech on December 04, 2017, 11:14:08 pmhttps://youtu.be/svJXiMMZzcQ

author: Fungus
author_rank: Super Contributor
timestamp: December 05, 2017, 06:49:42 am
content: Quote from: tautech on December 04, 2017, 11:14:08 pmYes, but the reason it can do that is because it's non-latching (and sounds nasty when you use it). Still, at this price range and in a hurry you're unlikely to get better.I always felt like a buzzing multimeter is the wrong way to do continuity. I'd like a LED on the probe that's in my hand. Maybe something could be built with an Arduino.

author: kalel
author_rank: Frequent Contributor
timestamp: December 05, 2017, 06:59:07 am
content: Quote from: Fungus on December 05, 2017, 06:49:42 amThat's a good idea, but depending on implementation, it might still be easier to hear the sound than focus on the light.

author: Fungus
author_rank: Super Contributor
timestamp: December 05, 2017, 07:03:55 am
content: Quote from: kalel on December 05, 2017, 06:59:07 amIf you're not looking where the probe is then what use is a buzzer?
I want a Dongle to measure the S21 and VSWR - Page 1
Forum section: electronics / testgear

author: xzswq21
author_rank: Frequent Contributor
timestamp: December 04, 2017, 06:53:07 pm
content: HelloI have a filter with SMA connectors at the input and output.I want to see the response from 100KHz or 1MHz to above... (I mean s21 and vswr)I have looked at many SDR dongles... there are many colorful dongles!is there a suitable device?Best Regards
Brymen BM257s: Current function stopped working suddenly; blank display - Page 1
Forum section: electronics / testgear

author: xraj
author_rank: Contributor
timestamp: December 02, 2017, 11:37:18 pm
content: Just wanted to relay my experience in case anyone else experiences something similar. The meter is about two years old with very light usage. It was bought off ebay (99centhobbies) in 2015.Today after measuring small currents in the 1A range, I turned off the meter. A few hours later, I turned it back on to the A function, and the display was blank. Turning it back to any other function, and the display would work normally. Turning it back to either of the current function and the display would go off. Long pressing any of the buttons would cause a beep, so it wasn't simply turning off.I found this older thread about calibration errors:https://www.eevblog.com/forum/testgear/brymen-257s-lost-calibration-data/In desperation, I followed the procedure there to enter calibration mode. Simply entering calibration mode, exiting and turning it off seems to have "fixed" it, because the current function now works again.I've also found that I can cause it to reset by pressing on the selector knob along the edge. I don't know if that's causing a fault or it's just losing power due to bad contact.I sent an email to Brymen support. We'll see what they say.

author: xraj
author_rank: Contributor
timestamp: December 04, 2017, 06:44:47 pm
content: Support got back to me.Apparently the calibration mode trick wasn't so crazy after all. He suggested that it had lost calibration and gave me the same directions for putting it in calibration mode and turning it off.

author: SkyMaster
author_rank: Frequent Contributor
timestamp: December 06, 2017, 06:14:56 am
content: Thank you for sharing your experience with us.I never had any problem with any of my Brymen multimeters, but you never know.
A great price for a 54831D with all the probes, but... - Page 1
Forum section: electronics / testgear

author: Jwalling
author_rank: Unknown
timestamp: December 03, 2017, 11:32:58 am
content: https://www.ebay.com/itm/162706183353?ul_noapp=trueA fantastic price if working, especially as it comes with 4 1165A probes and the MSO probe as well.However, I'm wondering why CH4 is obviously skewed. Also the falling edge on CH3 is suspicious as well.Self calibration hasn't been done since 2013.Well, at least they did the keyboard and knob test; that's important!And this is Lecroys ebay outlet, you'd think they'd know better!

author: nctnico
author_rank: Super Contributor
timestamp: December 03, 2017, 01:18:06 pm
content: CH3 looks like probe compensation because the rising edge isn't kosher either. It is a nice scope but I don't like the 640x480 display combined with digital channels.

author: Jwalling
author_rank: Unknown
timestamp: December 04, 2017, 11:05:02 am
content: Yeah, you're probably right about the probe comp. Looks like someone bought it shortly after I posted that. Must be someone that reads here...
Prova903 Dual Channel multimeter with Data logging - Page 1
Forum section: electronics / testgear

author: Metermeister
author_rank: Contributor
timestamp: December 01, 2017, 09:12:26 pm
content: I need data logging multimeter that's True RMS I found one on EBay. Prova903 seems very nice and one seller has good deal going approx 150us. It's DUAL channel Think can be very useful. So my question is simple.. is this good buy ? ANY OTHER Dual channel meters atbthis price? Sirry for my english.

author: AndyBollo
author_rank: Newbie
timestamp: December 02, 2017, 04:08:55 am
content: What about an UNI-T UT61E? Just $34.16USD!! You have to hurry, is the last one.https://www.ebay.com/itm/New-UNI-T-UT61E-LCD-Digital-Multimeter-Manual-Auto-Range-Test-Device-Analyzer/132333343986?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m2763.l2649Well, is not a dual channel but is super cheap.

author: Performa01
author_rank: Super Contributor
timestamp: December 02, 2017, 11:51:56 pm
content: Well, I have one and it's generally a nice and robust meter.Considering its specs and features, it would be well worth $150,-I've bought mine as a demo instrument for about the same price (+VAT).It turned out my sample did not meet the accuracy specifications for the 6V and 60V ranges and I could not find a calibration manual anywhere (that's the downside of buying no-name stuff).After that I lost interest, so I also have never tried the actual data logging. I use a proper lab bench DMM for that...Long story short: The instrument is nice as long as it meets its specs, but if it doesn't, how do you calibrate it?

author: Metermeister
author_rank: Contributor
timestamp: December 03, 2017, 08:55:38 pm
content: Thank you for feedback. I see it's more like 140us so it's definste value. I have no idea about calibration but I'm hope it's not far off from spec. I real like DUAL channel something that's rare on handheld meters. How is continuity on Prova903?

author: Performa01
author_rank: Super Contributor
timestamp: December 04, 2017, 09:40:17 am
content: Most definitely very tempting at that price.On mine, 6v and 60V were off, as already stated. All other voltage ranges and particularly the current ranges have been impressively accurate though.Continuity is from the instant "scratchy" type - that's the one I like best anyway. That means, its response is lightning fast.
Current-Clamp Multimeter with power factor (cos phi) - Page 1
Forum section: electronics / testgear

author: 2X
author_rank: Frequent Contributor
timestamp: December 02, 2017, 05:33:41 pm
content: Hello,does anyone knows a Fluke Current-Clamp Multimeter that measures "power factor (cos phi)" (& with bluetooth connection) from fluke brand? I have found one from BENNING but it doesn't have bluetooth connection.Power Current-Clamp Multimeter BENNING CM 8https://www.benning.de/benning-cm-8-us.html
MLC500 or MLC-500 Inductor & Capacitor Meter - Page 1
Forum section: electronics / testgear

author: czecht
author_rank: Newbie
timestamp: December 07, 2017, 12:10:59 am
content: I'm looking for anyone who has this meter or knows anything about it.I also would like to get the software that was missing in my shipment, but the Chinese seller doesn't respond to any emails... That is how it goes!If I'm not leaving this in appropriate place, please forgive me, this is my first time here.Thank you all for your help.Tony
Unusual reference oscillator frequencies in test equipment - Page 1
Forum section: electronics / testgear

author: Scratch.HTF
author_rank: Regular Contributor
timestamp: November 30, 2017, 02:42:31 am
content: I would consider a reference/master (timebase) oscillator frequency other than a commonly used 10 MHz or a reference which 10 MHz cannot be divided or multiplied by an integer (for the following examples with a 10 MHz input: 50 MHz with a NB3N502 PLL multiplier (set to x5) for the FeelTech FY6600 arbitrary function generator, or 5 MHz with a divide-by-2 counter for the Philips PM5390 signal generator; both pieces of equipment have been modified for an external reference frequency input) to be unusual in test equipment.Examples of an unusual reference (as per my definition) I have seen (so far) in test equipment include the following:* Philips PM5193 function generator (8.589934592 MHz)* Atten F2700-C frequency counter (13 MHz)* Philips PM541x/PM551x TV pattern generator (5.034964 MHz - applicable only for models supporting NTSC and/or PAL-M (both 525 lines); 625 line PAL and SECAM uses a 5 MHz master oscillator)* Kenwood SG-5110/5115 signal generator (16 MHz)If you know of a piece of test equipment (nothing else!) which uses an unusual reference frequency as per my definition, please post it here.

author: cdev
author_rank: Super Contributor
timestamp: November 30, 2017, 04:29:35 am
content: What is the reference frequency used in the Feeltech FY3224?

author: David Hess
author_rank: Super Contributor
timestamp: November 30, 2017, 10:03:49 pm
content: Integrating ADCs commonly used frequencies like 20.48 kHz, 40 kHz, 163.84 kHz, or 400 kHz to control integration time such that nulls were produced at the harmonics of the AC power line frequency.

author: Scratch.HTF
author_rank: Regular Contributor
timestamp: December 02, 2017, 05:10:01 am
content: I have noted that a DDS IC (e.g. AD9851 which has a selectable internal 6X reference clock multiplier of which can handle a 5-30 MHz reference clock with the multiplier enabled; alternatively, a PLL multiplier IC set to an appropriate multiplier can additionally be used for DDS ICs which do not have an internal reference clock multiplier) and a programmed microcontroller can be used with a 10 MHz reference oscillator and a simple automatic external clock switching circuit to generate the desired reference frequency with a typical error of less than one part per billion (PPB) when programmed in the MHz range e.g. an AD9851 with a perfectly accurate 10 MHz input internally multiplied by 6 and programmed to generate 8.589934592 MHz for a Philips PM5193 results in a master clock error of 0.201 parts per billion.
[Fixed] BM235 issue no Loz DC, Voltage, ohms and diode - Page 1
Forum section: electronics / testgear

author: taiteki
author_rank: Contributor
timestamp: November 30, 2017, 05:30:03 pm
content: I buyed 1 year and a half a bm235for the first time a the dmm have a dim lcd but i doncared about that because i can read with no problems.but some weeks ago the DMM stop to work poperly, i suppossed to be a battery problems and buy some new battery, but the issue continue.The dmm dont work in voltage LoZ,DC, ohms and diode.1 Loz, i put a 9V battery with arround 8,3V and got this.2 DC the same with the DC range.3 the ohms start with 0L but after short the terminas always show 0000.0ohms4 in diode always show 0.000vsome one have the same problem?thanks and apologies for my english.

author: retiredcaps
author_rank: Super Contributor
timestamp: November 30, 2017, 07:40:42 pm
content: Check the soldering on the inductor. See

author: taiteki
author_rank: Contributor
timestamp: November 30, 2017, 09:39:13 pm
content: Thx retiredcaps.dont remenber that video!.L3 disapeared.i put a new ferrite bead and

author: retiredcaps
author_rank: Super Contributor
timestamp: November 30, 2017, 10:12:41 pm
content: Quote from: taiteki on November 30, 2017, 09:39:13 pmI wonder if this L3 will be a long term problem? You are the 3rd or 4th person to have this bad soldering problem.BTW, for the LCD contrast Dave did a video too.

author: retiredcaps
author_rank: Super Contributor
timestamp: November 30, 2017, 10:16:15 pm
content: We are also finding out that on some older Fluke 17x series, the soldering on that inductor/ferrite bead has aslo degraded or shook loose due to abuse? However, this is over several years, possibly one decade.https://www.eevblog.com/forum/repair/fluke-179-repair/https://www.eevblog.com/forum/repair/fluke-179-not-working/https://www.eevblog.com/forum/repair/fluke-179-76688/

author: retiredcaps
author_rank: Super Contributor
timestamp: November 30, 2017, 10:23:42 pm
content: Thread for dim lcd on BM235.https://www.eevblog.com/forum/testgear/eevblog-brymen-bm235-lcd-issues-or-normal/

author: joeqsmith
author_rank: Super Contributor
timestamp: December 01, 2017, 12:04:12 am
content: Mine had a notch cut out I assume for this reason.https://youtu.be/g3uYcHAumhA?t=436

author: taiteki
author_rank: Contributor
timestamp: December 01, 2017, 06:32:16 pm
content: Thxs for the links.in the case of this DMM it was in a non climatized zone, 40ºC-45ºC in summer and 8ºC-20ºC winter (Seville-Spain).Possibly it has been damaged for a long time, since I have only used it to measure current.in the image of my dmm it seems that the ferrite bean broke apart.
is the kenwood cs-8010 any good - Page 1
Forum section: electronics / testgear

author: corronius
author_rank: Newbie
timestamp: December 02, 2017, 09:43:17 pm
content: i found a cs-8010 for $55 but it says its untested. i have never owned an oscilloscope before but i know that the old dsos are not as good as old analog scopes. i couldn't find any info on this scope does anyone know if this is a combination scope or just a straight up dso. it says its un tested but the display shows a trace what is the likelihood that there is something wrong? would this be a good beginners scope?
HP 3325B - Page 1
Forum section: electronics / testgear

author: uli
author_rank: Newbie
timestamp: November 30, 2017, 11:12:09 am
content: Hi all,I detected that my HP3325B has exactly double amplitude all the time: When e.g. I command 1Vpp, the osciloscope shows 2Vpp. When I command 1V RMS, I see 2V RMS on my voltmeter. I also delivers 20Vpp at max instead of 10Vpp max.Does anyone of you have an idea to it? Unfortunately I do not have a service manual with calibration procedure. But before entering to that I would like to get your inputs. May be I misunderstand something here.Regards,Ulrich

author: Berni
author_rank: Super Contributor
timestamp: November 30, 2017, 11:21:01 am
content: Turn on 50Ohm termination on your scope.

author: uli
author_rank: Newbie
timestamp: November 30, 2017, 11:28:17 am
content: Hi Berni,that immediate reply was as quick as precise and simple: I have a scope with 50Ohm input, and thought I had selected that but it was not the case - shame on me! Thank you very much, Berni.Regards,Ulrich

author: Berni
author_rank: Super Contributor
timestamp: November 30, 2017, 01:37:55 pm
content: No problem. Its common that people forget that most of the time signal generators are calibrated in to a 50 Ohm load.I quite appreciate the feature on modern digital ones that let you choose weather to show all voltages for a 50Ohm load or into a open circuit load.
Cleaning bare aluminum front panel - Page 1
Forum section: electronics / testgear

author: ruairi
author_rank: Frequent Contributor
timestamp: November 30, 2017, 05:25:19 am
content: Hi all,I have an Eico 1030 high voltage tube power supply that works beautifully. Before it came to me it was stored in a dusty environment and someone tried to wipe it down with some kind of damp cloth, maybe water or alcohol. The dirt and dust has streaked across the bare aluminum panel.What's the best approach to clean this?

author: floobydust
author_rank: Super Contributor
timestamp: November 30, 2017, 05:51:10 am
content: I think you clean this in a few passes. You do not want to wreck the silkscreen ink and this probably has a clear-coat over top.I would use mild dishsoap and warm water and a wet/damp micro-fiber rag to gently wipe off as much dirt as possible. Use (soap+water soaked) q-tips to gently scrub. A used soft toothbrush is also OK, if you make a little puddle and gently scrub an area. Go with the grain of the brushed aluminum finish. Go easy on the lettering and silkscreen.After that, if needed I use isopropyl alcohol and q-tip to swab off any tough oil/grease remaining stains, get in the nooks and tight spots on the knobs etc.Try not to flood the switches or meters with water.It's a nice HV power supply. I would replace the electrolytic capacitors as part of restoration.https://www.radiomuseum.org/r/eico_1030_regulated_power_supp.html

author: ruairi
author_rank: Frequent Contributor
timestamp: November 30, 2017, 06:30:16 am
content: Thanks Flooby,I'm not sure that it has any clear coat, it seems very raw. Good advice though thanks.I have a Schlumberger/Heathkit so this is surplus but it works beautifully, I will probably clean it up and sell it, maybe with a recap if needed as you say.
Is the Griffiths book on Oscilloscope restoration recommended? - Page 1
Forum section: electronics / testgear

author: qu1j0t3
author_rank: Regular Contributor
timestamp: November 29, 2017, 11:42:43 pm
content: Hi,I'm new to 'scope restoration and I have three HP's to deal with (1703, 1741 mostly working, and 1746).Is the Stanley Griffiths book ("Oscilloscopes: Selecting and Restoring a Classic") going to be of much practical assistance with 17xx vintage instruments? Or is it too generic/pitched to older scopes?Thanks for any advice

author: Testtech
author_rank: Regular Contributor
timestamp: November 30, 2017, 12:14:20 am
content: It is a reference for the Tek tube scopes, 545, 547, etc..

author: KE5FX
author_rank: Super Contributor
timestamp: November 30, 2017, 01:43:45 am
content: Stan's book is of interest primarily to fans of the older 500-series scopes. While valuable in that regard, it won't hold a great deal of relevance to people interested in the models introduced in the 1970s and later. There is no content that will be useful to people working with HP or other gear.Someonereallyneeds to do a new edition. I nominate... somebody else.
Similar product to Sencore PR570 (Variable Isolation Transformer)? - Page 1
Forum section: electronics / testgear

author: Fusion916
author_rank: Regular Contributor
timestamp: November 29, 2017, 09:51:31 pm
content: Does anybody know of a similar product with a considerably less price tag? I'm looking for the following:Input: 120V (US)Output: 0-120V but prefer 0-240VCurrent limitingCurrent display
Manual for biddle avo RM170 super megohmmeter  - Page 1
Forum section: electronics / testgear

author: evgeek
author_rank: Contributor
timestamp: January 16, 2017, 07:27:15 am
content: I have an old AVO RM170 super megohmmeter, I am looking for manual. Wondering if anyone has an instruction or schematic manual for this unit. I really appreciate your help. Thanks.

author: JohnUMB
author_rank: Newbie
timestamp: November 27, 2017, 06:13:43 pm
content: Hi,Apologies for only now 'joining': The Manual is at Electrotanya, but if there is anything specific you want 'measured/photographed' I can get my RM170 out of storage / collecting a working unit with a printed copy from Liverpool in a week. Going to compare to the more modern hp-Kyoritzu 4329A. Both occasionally appear on eBay. Regards.

author: evgeek
author_rank: Contributor
timestamp: November 28, 2017, 03:20:55 pm
content: Hi, thanks, i got the manual from that site. I couldn’t find that kind of triax connector. I am planning to replace with a different kind of triax connector.
Newlec NLINS3 megohmmeter quick teardown and mod. - Page 1
Forum section: electronics / testgear

author: shakalnokturn
author_rank: Super Contributor
timestamp: November 27, 2017, 09:39:03 pm
content: Picked this up cheapish and untested on the auction website so here it is:Identical to the Avo Megger BM223 less LCD backlight and a more CCCP look to it.Arrived working and good enough to call calibrated.250V range outputs 308V open circuit.500V range outputs 609V open circuit.1kV range outputs 1.18kV open circuit.100 ohms range outputs 4.6V open circuit.Short-circuit current is 1.73mA on megohm ranges, 200mA on 100ohm range.Digital display reads up to 1Gohm, bargaph quite a bit more.The rotary switch was disassembled for cleaning, it was a PITA to get back in place...While I was in there and thinking it was unfair that the Megger BM223 has a backlight but not this beautiful red meter, I checked if I could add one easily.It was done easily as it was already in there, one of the stopper pins to the rotary switch only needed shifting a notch further to enable the option.Now I'd like a "rotate to lock" push-button anyone know if miniature models can be found? Something that would fit without heavy modification.
EEVBlog HV Differential Probe - source for alternative tips? - Page 1
Forum section: electronics / testgear

author: Lorenzo_1
author_rank: Regular Contributor
timestamp: November 25, 2017, 01:13:23 am
content: Recently purchased the EEVBlog HVP-70 as I seem to spend half my time fixing SMPS problems. Latest one an aircon supply blown up by an Asian House Gecko that got across the bridge rectifier! She (who had eggs and was probably looking for someone warm and safe to lay them) got fried, as did the SMPS. Seems the aircon techs in north Qld make a nice living out of these guys. Happy with the investment as it already helped me get my LeCroy SMPS going again (shorted MosFET).Having been looking for some accessory tips - 4mm banana socket, 1kV, 20A or similar that will help me get into smaller spaces than the supplied ones. Have hunted around but it gets a bit confusing and don't want to order something that doesn't fit. Lots of scope probes but harder to find tips, lots of multimeter probe tips but not completely sure they'll suit. Looked at Pomona website without success. Suggestions/links to help narrow my search would be appreciated. I'd quite like to find a small kit with a range of tips in it.

author: IDEngineer
author_rank: Super Contributor
timestamp: November 25, 2017, 06:32:18 am
content: I make my own "tips", depending upon the circuit under test. I picked up a handful of these:...and I just connect whatever sort of contacts are necessary. For example, noise sensitive (such as high impedance) circuits get a short piece of solid wire (often resistor lead) screwed to each banana plug, and then touched to the circuit points. For others, I have a pair of micrograbber test leads that are cut short and screwed to banana plugs for easier connections when noise isn't as big a problem.My theory is that screw-based banana plugs let me customize the "test leads" to anything.

author: Lorenzo_1
author_rank: Regular Contributor
timestamp: November 25, 2017, 11:12:15 pm
content: Thanks - that's a good tip.

author: Russ
author_rank: Regular Contributor
timestamp: November 26, 2017, 06:00:56 pm
content: Quote from: IDEngineer on November 25, 2017, 06:32:18 amWhere did you get those?Thanks

author: Vtile
author_rank: Super Contributor
timestamp: November 27, 2017, 02:29:39 pm
content: Those look awfully lot of a Pomona design.http://www.pomonaelectronics.com/index.php?pageNum_rsProduct=4&totalRows_rsProduct=86&i=prodsub&parent=HWARE&cat=BANANAPLGJCK&getDetails=

author: IDEngineer
author_rank: Super Contributor
timestamp: November 27, 2017, 05:43:02 pm
content: Quote from: Russ on November 26, 2017, 06:00:56 pmSorry for the delayed response, we were travelling.These and many others like them are available from the usual distributors. That particular photo is from this item at DigiKey:https://www.digikey.com/product-detail/en/cinch-connectivity-solutions-johnson/108-0753-001/J149-ND/5927...which costs $1.35 for quantities up to 10.
FeelTech FY3224s sweep mode - trigger of sweep ramp function possible? - Page 1
Forum section: electronics / testgear

author: felixna
author_rank: Newbie
timestamp: December 21, 2016, 09:01:03 pm
content: Hi there,I have this low-cost FeelTech FY3224s function generator which is also discussed here:https://www.eevblog.com/forum/testgear/feeltech-fy3224s-24mhz-2-channel-dds-aw-function-signal-generator/.I use the sweep function but found no way to get a trigger for the ramp function of the sweep. The TTL output on the back sends square wave signal with the current sweep frequency but I need to trigger the scope on the start of a new sweep cycle (falling edge of the ramp function).Is this possible or is there a trick to acomplish this? I found nothing about this in the manual nor at google.Cheers,Felix

author: Celtic_Mist
author_rank: Newbie
timestamp: November 29, 2017, 04:24:18 pm
content: Hi Felixna,Did you ever find a solution?RegardsCeltic_Mist
UNI-T ut139c multimeter, broken, some functions stopped working - Page 1
Forum section: electronics / testgear

author: rspt1908
author_rank: Contributor
timestamp: November 23, 2017, 07:24:51 pm
content: Good day everyone,I had this meter for just short of a year now. I occasionally test each functions every month but I have never really used it yet in testing circuits as most of my projects then mostly involved programming or simultations. However, just today, I was trying to check the continuity of the cables and it just started beeping randomly even when the output is not shorted (multimeter is in continuity mode). I tried to check the other functions and confirmed that the Continuity Tester, Resistance Measurement, Temperature measurement and AC Voltage measurementno longer functionproperly. It just killed itself, I haven't even got to use it.( I have only confirmed DC Voltage measurement as well as the NCV to be the only functions still properly working.Video:https://youtu.be/nqIXN1PcZG4I tried to check the innards and saw some shavings near the rotary switch however removing them didn't solve the problem, I didn't find any solder blobs causing shorts on the PCB(.Does anyone have any ideas about this? I tried to look for the schematic online but could only find ones for the ut61e. Before purchasing, I read in some forums that turning on the meter while pressing some buttons may boot the meter in calibration mode and is sometimes enough to mess with the firmware on the eeprom. I have been careful to avoid this.I couldn't sleep so I tried to build jumper connectors for my power supply to distract myself to avail. I couldn't send it for repairs as I bought it from the US and I live in the Philippines. I have a project coming up for our coursework and I need to measure temperature to confirm the functionality of our project. It took me a while to save money for this meter and would like to try to fix it. I wouldn't want to throw this in the bin since it was barely usedPictures:1. Rotary switch shavings, Front PCB2. Back PCB 13. Back PCB 24. Back PCB 3Here are some people dealing with similar issues:1. UT139C sudden Brick after power on.no damage at all2. UNI-T UT139C: DO NOT WORK AUTO RANGE

author: hli
author_rank: Frequent Contributor
timestamp: November 24, 2017, 09:39:41 pm
content: First thing to check: put new, known-good batteries in.

author: rspt1908
author_rank: Contributor
timestamp: November 25, 2017, 03:41:26 am
content: Yup, I tried replacing the batteries but still yielded the same resultI used panasonic batteries

author: stj
author_rank: Super Contributor
timestamp: November 26, 2017, 06:15:33 am
content: clean the switch contacts and tracks with IPA or alcahol.dirty contacts will cause problems like that.

author: rspt1908
author_rank: Contributor
timestamp: November 26, 2017, 03:36:44 pm
content: Yup, I tried to clean the rotary contacts to no avail. I found some plastic shavings as indicated in the picture
HP E3631A schematic - Page 1
Forum section: electronics / testgear

author: wictor
author_rank: Regular Contributor
timestamp: November 26, 2017, 08:32:34 am
content: Hi,Does anyone have schematic from earlier version of HP E3631A power supply service manual. That manual is printed in Korea 1996 or 1997 and those schematics are different from Agilent E3631A PDF service manual from year 2000 that can be found from net.Thanks,wictor

author: bd139
author_rank: Super Contributor
timestamp: November 26, 2017, 10:29:33 am
content: What do you need it for specifically? Nearly all of the E36xx power supplies have the same basic circuit apart from the control/digital sections.

author: wictor
author_rank: Regular Contributor
timestamp: November 26, 2017, 01:55:55 pm
content: Quote from: bd139 on November 26, 2017, 10:29:33 amI just wanted to see the differencies. And since I have older model, I would like to get the correct schematic for this model.

author: bd139
author_rank: Super Contributor
timestamp: November 26, 2017, 02:02:00 pm
content: Fair points!I had a look around but I couldn't find one. If you do find one, please do post back as it'd be interesting to see how similar this is to the earlier model E3630's.
Tektronix TDS7104, thinking of buying... - Page 1
Forum section: electronics / testgear

author: SpeedD408
author_rank: Newbie
timestamp: November 26, 2017, 04:12:03 am
content: Hello,I’m in the marker for a scope. I’ve been watching the EEVBlog videos and looked at spec sheets and trying to figure out the one I want. I’ve been looking and almost pulled the trigger on a Rigol DS4032 as TEquip had a special going (free 500mhz and serial decode upgrades) I didn’t do it as $2700 for a hobby is a lot. So started looking on auctions sites and the old Tektronix TDS7104 looks very interesting. 1 GHz bandwidth, 10GS/s, 4 Ch, but looks to be 10years old and it runs Win XP so it is slow to boot up and probably weighs 50 lbs and is large. However, I don’t think I can beat the features for my budget but I’m having a hard time justifying that kind of money on 10 year old gear which could die at any point.What is the normal lifespan of this unit?I read the thread on the high failure rate of the Maxim DS1245yp-100 , but that seem to be the only negative.Anything I should know before forking out the cash?Thanks....Sent from my iPad using Tapatalk

author: TheSteve
author_rank: Unknown
timestamp: November 26, 2017, 04:37:59 am
content: What are your requirements? Newer scopes have decode options which are very nice.

author: nctnico
author_rank: Super Contributor
timestamp: November 26, 2017, 10:58:25 am
content: One of the problems with older high bandwidth DSOs is noise. That is not just due to their higher bandwidth but also the noise of the ADCs is much higher. I wouldn't recommend such a scope because it will be near useless for low frequency work. You'll have to turn on high-res or averaging all the time which come with their limitations like not being able to use peak-detect at the same time.For this reason I have multiple oscilloscopes. I have a GW Instek GDS2204E (200MHz 4 channels) for low frequency work. It's noise is just above 1LSB of the AD converter so you get a (near) flat line if you short the input and it is perfect for working on analog stuff. For high frequency work I have an Agilent 54835 which (when uphacked to a 54845) is pretty close in specs compared to the TDS7104.

author: SpeedD408
author_rank: Newbie
timestamp: November 26, 2017, 12:57:00 pm
content: My requirements are not very high so I know I have over kill on the brain, but I do simple retro computer repairs and I am considering taking that to the next level as well as looking into pinball/video game board repairs. I used to do Apple II, pinball/video arcade repairs back in '82-86. So I'm brushing up on my skills. Is a 1GHz scope required for this no. However, if a new 200-350Mhz is the more than an older 1GHz scope with 10x the sample rate I figured it was worth looking at.Noise... I hadn't considered that. I would have though that the ADCs would have been dead quiet at lower frequencies. This is good to know.Decodes - UART/RS-232 would be most used, then I2C and maybe SPI.Thanks for the help.
I want to flip your lid! - Page 1
Forum section: electronics / testgear

author: Jwalling
author_rank: Unknown
timestamp: November 24, 2017, 10:59:47 pm
content: https://www.ebay.com/itm/HP-Hewlett-Packard-Cerjac-OC-12-Circuit-Board-02-2400-2080/152801364447?hash=item2393abc9df:g:~UoAAOSwVqlZ6z0OI so want to de-cap the massive chip on this board... If it were less than 30 bucks I'd buy it.

author: SeanB
author_rank: Super Contributor
timestamp: November 25, 2017, 08:33:33 am
content: Standard Hybrid chip there, though it is soldered in upside down so the ceramic case side is a heatsink mount. Inside there will be a white ceramic multilayer substrate, gold traces in multiple layers and silver soldered chips on the ceramic with gold bond wires, along with thick film resistors, diodes, transistors and probably some matched length traces to pass the high speed signals through the glass seals, along with likely some ceramic chip capacitors and some solid tantalum, most likely wet tantalum, decoupling capacitors soldered to the board.

author: Jwalling
author_rank: Unknown
timestamp: November 25, 2017, 11:18:00 am
content: Oh. I had thought that the chip was socketed...

author: SeanB
author_rank: Super Contributor
timestamp: November 25, 2017, 02:48:11 pm
content: Lid is soldered to the case, so opening will be destructive.
Tenma 72-330 oscilloscope manual? - Page 1
Forum section: electronics / testgear

author: Axtman
author_rank: Regular Contributor
timestamp: November 20, 2017, 03:22:11 am
content: Hello. Does anyone have a manual for a Tenma 72-330 oscilloscope? I recently picked one up cheap and am looking to calibrate it. Thank you.

author: harveyradar
author_rank: Contributor
timestamp: November 20, 2017, 12:33:21 pm
content: This is a HUNG CHANG OS-635 CRO.The handbook is fairly easily found using the usual search engine and contains schematic and servicing info.

author: Axtman
author_rank: Regular Contributor
timestamp: November 25, 2017, 06:32:36 am
content: Thanks. I found the manual.If anyone wants a copy, just email me.
Is a Dyna Jet 707 worth the gamble? - Page 1
Forum section: electronics / testgear

author: Inverted18650
author_rank: Frequent Contributor
timestamp: November 25, 2017, 01:20:10 am
content: Greetings All,I found this Dyna Jet Model 707, tube tester for sale at a local antique store and the tag on it states "functions perfectly just $150." Does anyone have experience with this bit of kit and should I gamble $150 on it? It is in good condition and has all original case and even the manuals. If I chooce to pass, would anyone else like me to grab for them? I may be able to negotiate the price a little as well. I welcome any all and input from the experienced tube pro's, as I am still learning the trade.Thank you all,Chris
Flashing & clicking display on HP E2378A multimeter - Page 1
Forum section: electronics / testgear

author: T Michael
author_rank: Newbie
timestamp: November 25, 2017, 05:45:42 pm
content: Hi, I did a nono yesterday, trying to test continuity on a hot circuit. Thought that if the multimeter was isolated, it wouldn't matter if the ckt had 120 volts ac on it.Wrong, now my HP multimeter display flashes all the elements, clicks, turns off, then repeats.Sounds bad. Does anyone have an idea how to reset or restore function to the display? I tried new batteries to no avail.Thanks, Sadly T. Michael

author: retiredcaps
author_rank: Super Contributor
timestamp: November 25, 2017, 09:44:14 pm
content: Post some pictures of the pcb and inside. The HP is likely made by Yokogawa. Seehttp://mrmodemhead.com/blog/yokogawa-7534-03-multimeter/One of the downsides of this meter is that the Volt/ohm jack is shared with uA/mA. So depending on what you were doing, how things were connected and how you had the probes plugged in on a live circuit, you can do some possibly unrepairable damage to your meter.BTW, 120 VAC can be up to 400 VDC if rectified and PFC is involved. And you could have done damage to whatever circuit you were measuring.
Linux on the Agilent 16902A Logic Analyzer - Short HowTo - Page 1
Forum section: electronics / testgear

author: DocBen
author_rank: Regular Contributor
timestamp: November 26, 2017, 10:51:56 am
content: So I recently bought an Agilent 16902a. I looked at the datasheet of the VP22 mainboard and it says: runs Linux.I thought I'd give it a try.The memory is limited to 512MB and cant be upgraded even though there is an available third socketThat leaves relativly little choice of distributions and I've chosen Lubuntu which is optimized for these kinds of situations.Download a current i386 based image. I've used 17.10 Artful Aardvark.Burn it to a DVD (dont know if all of these have DVD Drives, but it can boot from USB).It installed. During that time sometimes buttons do not appear on screen, but pressing Enter does the job just fine.However when starting the system the chosen resolution is 640x480 even though the display is larger.This can be remedeed by:sudo nano /etc/default/grubuncomment the line:#GRUB_TERMINAL=console(so should read: GRUB_TERMINAL=console)save. exit.sudo update-grubreboot. profit.Thats it. Not much more to it.Now after I've done most of the work, would someone from Keysight kindly write the drivers and software that this beauty can be used under Linux?(I really think it shouldn't be too hard: the 16700s were HP-UX, and the source code is probably still around plus Linux is easier to program for as some of the work has already been done (libiio, gtkwave and sigrok for example), might be an interesting excercise if your trying to get rid of windows ce for newer devices)
Rigol 1052E XY mode question - Page 1
Forum section: electronics / testgear

author: dorkshoei
author_rank: Frequent Contributor
timestamp: November 18, 2017, 12:55:29 am
content: I have a 1052E that's been hacked to 100mhz. I have an old piece of equipment that outputs an X, Y and Z "vector" signal onto a display tube. Hooking up the Rigol in place of the tube, I can see the picture but it's small in the lower right corner of the screen. Adjusting scale full on X and Y increases it's size slightly, but still the image is barely taking up any of the screen. Am I missing something? I've had no issue filling the entire display area using an old HP analog scope.

author: vk6zgo
author_rank: Super Contributor
timestamp: November 20, 2017, 09:26:05 am
content: Are you sure the signals don't have a DC offset?

author: rstofer
author_rank: Super Contributor
timestamp: November 20, 2017, 04:58:15 pm
content: Maybe put a capacitor in series with each signal and use AC coupling? I'm not sure about the Z input and whether it should be capacitively coupled.

author: dorkshoei
author_rank: Frequent Contributor
timestamp: November 20, 2017, 05:00:01 pm
content: Quote from: rstofer on November 20, 2017, 04:58:15 pmI figured out the issue. I was misunderstanding the controls. They don't work quite the same way as my older analog.Question. Is there a z-input (intensity) on the 1052? It would also be nice if there was a persistence option in-between none and infinite (but realize that would be tricky to implement and somewhat comes for free on analog scopes).

author: Keysight DanielBogdanoff
author_rank: Unknown
timestamp: November 22, 2017, 04:39:37 am
content: Having a Z-input is pretty rare for digital scopes. I know there are a couple out there but don't remember specifically what models they are.

author: AG6QR
author_rank: Frequent Contributor
timestamp: November 22, 2017, 05:30:36 am
content: Quote from: Keysight DanielBogdanoff on November 22, 2017, 04:39:37 amCorrect, and to directly answer the specific question asked, no, the Rigol 1052E definitely does not have a Z input.

author: dorkshoei
author_rank: Frequent Contributor
timestamp: November 22, 2017, 05:34:05 am
content: Quote from: AG6QR on November 22, 2017, 05:30:36 amYes I concluded this was the case. Anyone know which digital scopes have a Z-axis input? I've read that some higher ends scopes also have configurable "digital persistence".
DS1054 Firmware - Page 1
Forum section: electronics / testgear

author: Mattjd
author_rank: Regular Contributor
timestamp: November 22, 2017, 01:34:59 am
content: HeyoooRecently got a 1054z. I was looking at the firmware to make sure to have the latest. The latest is 00.04.04.03.02On the scope, going through utility -> system -> system info I see the software version is 00.04.04.SP3Im not sure if i should bother with buying a flash drive, configuring it, and installing the software on rigol's site or not.
Something wrong with my N9320A spectrum analyzer - Page 1
Forum section: electronics / testgear

author: wldshy
author_rank: Contributor
timestamp: November 21, 2017, 03:18:42 am
content: Hi guysthere are something wrong with my spectrum analyzer, its signal level is 30db lower then excepted.for example I feed a 10MHz 0dbm into, it shows 10MHz -30dbm,like following picture.and when try to calibrate ifself, it shows an error with ERROR 654,TO LOW INPUT, like this.is there anyone have same suggestion?or where can I get service guide of the module. there is noting help on keysight website.

author: Neganur
author_rank: Unknown
timestamp: November 21, 2017, 03:47:20 pm
content: Run a mechanical attenuators check from the service or alignment menu (don’t remember which).

author: nctnico
author_rank: Super Contributor
timestamp: November 21, 2017, 04:26:20 pm
content: I see mdBm on the generator. Anyway, I'd check the signal from the generator's output with an oscilloscope to make sure the problem is in the spectrum analyser or generator.

author: AF6LJ
author_rank: Unknown
timestamp: November 21, 2017, 07:45:34 pm
content: That's not a good sign, when you switch in different amounts of attenuation does the Analyzer show a correct value or are all the attenuator positions off by 30DB??

author: xmo
author_rank: Regular Contributor
timestamp: November 21, 2017, 10:28:43 pm
content: Does the front panel calibrator signal also measure 30 dB too low?
ASCOM PRONET1 - Page 1
Forum section: electronics / testgear

author: dimis40
author_rank: Newbie
timestamp: November 21, 2017, 04:19:19 pm
content: Hello from Greece. Recently i bought an ASCOM PRONET1 without cables and power supply. I dont know anything regarding usage or how to make it work. Aldo as you can see inside are some cables which are not linked to the board and a battery compartment. Could anyone give me information for this device ?
Repairing burnt diode for DE5000 (battery short) - Page 1
Forum section: electronics / testgear

author: ironcurtain
author_rank: Regular Contributor
timestamp: November 20, 2017, 02:47:40 pm
content: Hi,I installed the battery wrong the first time and the zener diode in the position D5 next to the battery wires in my DE5000 failed/burned. I am not sure which type of diode it is, and I would really appreciate if someone could tell me what kind it is so I can repair it today.Needless to say even if I quickly figured out I had switched polarity, the zener was dead and they die creating a short... not open circuit, so after reinstalling the battery properly it was shorted and it heated up pretty good. Luckily I opened up the case and removed it before things got a little... hotter.Never open up your test equipment when sleep deprived I guess!

author: TheRadioGeek
author_rank: Contributor
timestamp: November 20, 2017, 09:06:59 pm
content: Sorry to hear about your meter getting hit with a reversed battery. I don't know what diode is used for D5 but I did find some talk about it in the following thread. its reply #12.https://www.eevblog.com/forum/testgear/der-ee-de-5000-unboxing-and-teardown/It sounds like that diode should have protected the meter unless it was missing or something.Good luck maybe someone else will have an idea.The Radio Geek.
SCPI (VISA) query commands with "?" on Rigol DG1032Z AWG - Page 1
Forum section: electronics / testgear

author: aharmony
author_rank: Newbie
timestamp: November 20, 2017, 02:26:02 pm
content: Hi everyone!I'm hoping that someone here might be able to shed some light on the troubles I'm having using SPCI on the Rigol DG1032Z waveform generator. I am new to SPCI, so maybe it is something I am misunderstanding with the syntax I am using.I've got one one of these Rigol AWGs in the lab (firmware 00.01.12 - most recent) and am having troubles with certain SCPI commands sent to the device. I'm trying to set up some automated data logging with the instrument, but for some reason many of the SPCI commands including a '?' to receive values from the instrument throw the SPCI error "-113 Undefined header".The instrument connects over VISA(USB) just fine. I can identify the instrument with*IDN?just fine and even send a lot of setting commands to the DG1032z, and they work just fine without error (for example, the setting commandCOUNter ONto turn on the frequency counter function, orCOUN:COUP ACto turn the frequency counter to AC coupling). But for some reason, many of the commands including a "?" that query information from the device all throw Error 133.Some "?" commands work, but others do not. For example,COUN:FREQ?does not work, and throws error 113. ButCOUN:COUP?does indeed return the coupling of the frequency counter function.Ultimately I am logging data through MATLAB, but I have minimised the SCPI setup for debugging this issue by sending/reading SCPI over VISA(USB) directly with Rigol's Ultra Sigma software. I have also tried with the VISA terminal in Keysight's Connection Expert utility, and the same results are repeated there.Maybe there is something that I am missing with my understanding of the SCPI syntax for this device, but even the examples shown in the DG1000 Programming Guide throw error 133. Can anyone spot something amiss? Or does anyone know if there are some SCPI irregularities with this particular test instrument? As I mentioned above, I've updated the DG1032z to the latest firmware from Rigol to see if it's a bug and if that fixes the problem, but the results are the same even on the fresh firmware. So I'm hoping that I am misunderstanding! Thanks for any help.Here are some example queries and their results, screencapped...

author: aharmony
author_rank: Newbie
timestamp: November 20, 2017, 03:35:00 pm
content: Oooh, well then! Case solved. I'm an idiotAfter a day of wrestling with this yesterday and fumbling around with it today some, I have now realised that I was using commands from the DG1000 Programming Manual from Rigol - not, in fact - the DG1000ZProgramming Manual.So for anyone else that might have that problem (I doubt it...) here's the solution: The DG1000 and DG1000Z have different programming manuals! D'uh!All works well now!

author: _Wim_
author_rank: Super Contributor
timestamp: November 20, 2017, 08:00:43 pm
content: I know that feeling! Happens to the best of us. Good to have solved it yourself!