Merc-o-Tronic 172 Peak Kilovolt meter – History?

[debe]

This is certainly not for Television EHT measurements, its for automotive work & would have had a probe. I still have my 30KV HV probe & Sanwa meter that I used for TV work, TV EHT on coloured TV was around 25KV.

[legendre]

So is there a consensus that the KV input used a high-voltage probe that’s no longer present?

Fair enough, as nothing else makes sense.. the connectors & circuitry are not suitable for anything north of 600V in my view. But I still can’t understand the cross-wired input terminals – what’s the point of that arrangement? If they want the HV probe to be plugged in "backwards" they could have marked or color-coded the banana pins on the probe connector to match whatever polarity they desired. Why have a second set of cross-wired jacks for this?

Next thing, need to find out what the divider ratio is for the 60KV scale, so the probe ratio can be determined and duplicated. There’s an old EICO HV probe body around here somewhere, missing the internal resistance. Maybe it can be adapted to work with this meter?

Gotta do something with it, lol.

@BillW

Did you find anything?

[debe]

Your pretty close now. The circuitry would be to stabilise the peak pulses in an ignition circuit, to give a steady reading.

[billw]

Mind is like a sieve….sorry; I forgot! Busy weekend, too. I will check tonight; but whatever brand is down in the basement, I do know it has a kilovolt scale because I had wondered how the heck that would work….

Long live American manufacturing!

[billw]

Better late than never, or at least that’s what they say. I found mine. It is a Mercotronic Model 871 but is almost identical to yours. My meter face says "peak volts/kilovolts." It came from an older OMC mechanic who used it for trouble shooting power pack-type ignitions. Mine does work, in that regard. Never tried Kilovolts….Anyway, when I used it on CD systems, I plugged my leads into "PV" assuming it meant peak volts.

Long live American manufacturing!

[bill-russell]

All modern cd ignition troubleshooting requires a peak reading volt meter to test staters and trigger voltages. Perhaps that is what your meter is for. Bill

[powerabout]

I have a Merc-o-tronic 172a peak meter, just picked it up as it was there.
I know Merc-o tronic as they made the custom diagnostic tools for Mercury in the 70’s
You need a peak reading meter to test cdi outboard ignitions so thats from about 1970 to they became EFI

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