Anybody use combined bench dmms like this? - Page 1
Forum section: electronics / testgear

author: 001
author_rank: Super Contributor
timestamp: April 13, 2018, 09:53:37 pm
content: LOLIt is vintage russian bench multimeterADC is 7107 clone + analog bar (with separate autorange circuit)Is it good idea or not?PS - it equipped with active HF probe (vacuum diode inside it)

author: EE-digger
author_rank: Frequent Contributor
timestamp: April 13, 2018, 10:34:05 pm
content: LCD is cracked at one end but could continue working for years that way.Does it do what you want? The analog meter can be helpful when making an analog adjustment or observing audio peaks, etc. Various DMMs implement this with a digital gas gauge at top or bottom of the readout.The advantage of your analog meter is that it has infinite resolution

author: 001
author_rank: Super Contributor
timestamp: April 13, 2018, 11:15:21 pm
content: Do you know some analogs from hp and others?

author: DaJMasta
author_rank: Super Contributor
timestamp: April 13, 2018, 11:29:10 pm
content: Quote from: EE-digger on April 13, 2018, 10:34:05 pmAnd finite precision to the point of not getting higher effective resolution than what you can estimate given the printed scale, but there's no reason to start this argument here.I think because of the size/shape of a readable analog dial, benchtop meters in this form factor were not so common when they were still in fashion. Most higher end analog meters you find are in the "handheld" style even if they're a bit big for that, and while you occasionally find combo meters like this one, once the manufacturer went digital, they generally didn't bother. You see them in older RF power meters sometimes, but multimeters are generally one or the other and what we think of as standard bench form factor meters are almost all digital.If you can test it and verify it's in good shape, I don't see why you can't use it - and there's probably ways of adjusting trimmers and such to get it back in spec if it's drifted around.

author: EE-digger
author_rank: Frequent Contributor
timestamp: April 13, 2018, 11:56:08 pm
content: No argument, I agree. It can still be handy for peaking or in lieu of an averaging function.

author: bicycleguy
author_rank: Frequent Contributor
timestamp: April 14, 2018, 01:30:01 am
content: Maybe you should put it in here:https://www.eevblog.com/forum/testgear/what-old(seldom)-piece-of-test-equipment-do-you-own-nostalgic-thread!/msg1450201/#msg1450201fixed link

author: rhb
author_rank: Super Contributor
timestamp: April 14, 2018, 01:31:48 am
content: VTVMs were very definitely not "hand held" unless you had *really* large hands. Not light weight either. The best you could get in a VOM was 50 K ohms/volt. A VTVM was 10 M ohms/volt. But you paid a price for having a tube and HV PS.If you want an analog meter, adding an FET input to a $3 1k/v meter is easy, cheap and makes them usable for low voltage. A high impedance FET VM was a popular project in ARRL handbooks 30 years ago.

author: 001
author_rank: Super Contributor
timestamp: April 14, 2018, 05:32:11 am
content: The analog meter is placed here after wide band rectifier (using opamps) and autorange circuit

author: Performa01
author_rank: Super Contributor
timestamp: April 14, 2018, 11:00:03 am
content: Here's a posting that has the image of a high quality combined analog/digital (handheld) meter attached:https://www.eevblog.com/forum/testgear/(quiz)-what-is-it/msg286689/#msg286689Metrix quite obviously gave priority to the analog meter, size-wise