Old DMM Failed Today - Page 1
Forum section: electronics / testgear

author: sarbog
author_rank: Contributor
timestamp: April 15, 2021, 11:36:44 pm
content: FYI,I have been using an old early 1990's vintage Beckman 2020 DMM. It failed today on RMS voltage.. I spent an hour, embarrassingly, trying to figure out why my circuit was not working properly. Then it dawned on me that maybe this old DMM is not working. I did some comparison tests and sure enough it was my old DMM... Duh..........

author: Nusa
author_rank: Super Contributor
timestamp: April 16, 2021, 01:50:32 am
content: Before you write off your old meter, make sure you try it with a new battery.

author: shakalnokturn
author_rank: Super Contributor
timestamp: April 16, 2021, 05:40:56 am
content: If bad only on AC Volts / Amps check the few electrolytic capacitors around the TRMS converter.

author: sarbog
author_rank: Contributor
timestamp: April 17, 2021, 10:47:05 pm
content: Yes, I will test the electrolytics, thanks.

author: rsjsouza
author_rank: Super Contributor
timestamp: April 17, 2021, 11:00:28 pm
content: You may also want to keep mr modemhead's page to give your meter an extra life...http://mrmodemhead.com/blog/beckman-3020-dmm-repair/

author: sarbog
author_rank: Contributor
timestamp: April 18, 2021, 12:01:27 am
content: But, still want to buy the Dave Jones GW-121

author: Nusa
author_rank: Super Contributor
timestamp: April 18, 2021, 12:15:27 am
content: His BM786 meter is also a solid choice.Everyone who is serious about electronics ends up with multiple meters. Not considered a problem, so long as you don't spend the rent money.

author: tautech
author_rank: Super Contributor
timestamp: April 18, 2021, 12:21:54 am
content: Quote from: Nusa on April 18, 2021, 12:15:27 amSorta fixed that ^ for you.

author: sarbog
author_rank: Contributor
timestamp: April 18, 2021, 01:10:32 am
content: A few pics of my multimeters since 1967, a Simpson 260, a Beckman 2020....... I have repaired both....

author: sarbog
author_rank: Contributor
timestamp: April 18, 2021, 01:11:43 am
content: My Beckman....

author: sarbog
author_rank: Contributor
timestamp: April 18, 2021, 01:52:30 am
content: Why is it better?

author: sarbog
author_rank: Contributor
timestamp: April 18, 2021, 02:09:35 am
content: Playing with the design from Dennis Hilll about a digital ESR meter ...... got it working very cool stuff ........ Thank you Dennis Hill.....

author: Michael YYZ
author_rank: Regular Contributor
timestamp: April 18, 2021, 02:19:19 am
content: I’ve got the same identical one, although mine is branded as Wavetek. Love it! It works perfectly well, except some plastic tabs broke off from the case and rotary button and now the latter spins 360 degrees. But fine, otherwise. I checked the True RMS measurement against my new Siglent SDS2104X Plus scope and obtained similar readings.https://www.eevblog.com/forum/testgear/hantek-dso5102p-different-measures-when-changing-the-coupling-(ac-vs-dc)/msg3549957/#msg3549957I hope you’ll be able to fix yours...Quote from: sarbog on April 18, 2021, 01:11:43 am

author: tautech
author_rank: Super Contributor
timestamp: April 18, 2021, 02:27:27 am
content: Quote from: sarbog on April 18, 2021, 01:52:30 am

author: shakalnokturn
author_rank: Super Contributor
timestamp: April 18, 2021, 04:02:53 pm
content: I used to own a Wavetek 2020 too, sold it in the end I had plenty more to hold on to, never got used the "menus" didn't like the feel of the function switch either.

author: sarbog
author_rank: Contributor
timestamp: April 30, 2021, 04:39:17 pm
content: My new EEVBlog DMM arrived today... very nice!

author: sarbog
author_rank: Contributor
timestamp: August 31, 2021, 12:39:22 am
content: Finally got around to taking my old Beckman Industrial multimeter apart.... model 2020 from late 1980's. It is working again on true rms ac + dc . I checked a lot of stuff, could not find any special true rms chips in it with a microcontroller... So I cleaned the big rotary switch, put it back together and now it is working.. very cool. Does anyone know how the true rms circuit is implemented?

author: Tycho_Brahe
author_rank: Contributor
timestamp: August 31, 2021, 01:14:09 am
content: Quote from: sarbog on April 18, 2021, 01:10:32 amNice Simpson! I have that same model meter that I got used recently. I'm repairing mine now. A 138 ohm resistor is open. I suspect someone connected it up to some high voltage in resistance mode? Not sure. The Rx100 mode is the only range broken. Afraid more components are bad, but starting with the one I know about.

author: sarbog
author_rank: Contributor
timestamp: August 31, 2021, 02:15:59 am
content: My first Simpson 260 I damaged in high school about 1969... cost me $200 for repairs........ was testing high voltage on my tube amp ham radio....