Danameter Copenhagen Type 500 Tube Voltmeter 1955 repair teardown

Danameter Copenhagen registered by Henning Jensen 1951
this unit is called Type 500 it is a tube based volt mA Ohm meter,
uses two probes for AC voltage or High voltage up to 50kV I dont have the probes.
Tubes 2 x E80CC dual triodes, 1 x EA50 signal diode,
Selenium rectifier bridge for anode supply was broken and used from 30 to 100W under my first test, but I was fast and aborted the test, before the nasty fire and smell.
new bridge in and now it works. Battery mega leakage also fixed.
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#vintage
#teardown
#repair
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I use auto generated subs, i am sorry there are a few spelling errors,
maybe one day they can do it better..
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[@garyramsey4275]

Beautiful, huge meter. I hope you finish bringing it back to life.

[@TeardownOZ2CPU]

I think i did

[@migsvensurfing6310]

It looks very very much like a Radiometer produced thing. I wonder if some company had it produced for them and slapped their name on it. I don't know if Radiometer did that for other companies.
I had a few years ago a Radiometer voltmeter this one seems extremely like it in the way it is produced and the components used. it was the Radiometer Polymeter RV21b.
Thanks for the teardown.
Oh by the way. Thermal runaway can be avoided by having a lamp in series when powering up but I beleive you know that.

[@SeanBZA]

Would have opened the old Siemens box and replaced the plates with 1N4007 diodes, to keep it looking original, and a whole 1A of current capability over the original 50mA.

[@splitprissm9339]

This is one style of restoration, but it can actually be quite confusing to the next person dealing with the internals. If you restore for use, replacing parts with functionally equivalent modern parts and making your modifications clearly recognizable often seems the most sane way - restoring for collection is another matter/philosophy.

[@splitprissm9339]

Comet sounds like an awfully fitting model name for something liable to blow up :) ... I wonder if there was EVER a VTVM design, apart from possibly HP level equipment, that used a stabilized DC power supply instead of one of these godforsaken batteries. .... .... I must admit I'd be completely unashamed about just cable tying in a modern battery holder (with some kapton tape and/or heatshrink around it. If the instrument has its measurement ground floating from the metal case, insulate the living daylights out of the battery stuff!) ... meter looks awfully similar to what is in the Bruel&Kjaer VTVMs, is that Jensen logo? ... Love the use of industrial grade tubes and a tape wound transformer core. Looks almost like a piece of military spec gear. .... With these rotary switches, I always find the insulation towards the posts a weak point - either wiring gets loose and shorts to the posts, or dirt creates an arc tracking path there.... German technicians loved to misspell selenium Gleichrichter as Gleichriechter ("It will smell in a moment").... these colored lens pilot lights rock, never seen yellow before.... 50kV, was this used to service projection TVs? Electron microscopes? Military gear? Transmitters? Can't think of much mainstream use for a 50kV range before color TV was introduced ... With bakelite, do resist the temptation to try and get them clean quickly with alkaline cleaners (eg oven spray, dishwasher powder....), bakelite seems to take them very badly unlike most modern plastics.

[@michaelturner4457]

That's probably the most corroded and crusty battery I've seen.