Do Little Jr wrote:

"Asimov" wrote in
message ...

[.... ]

Rare VTVM's used a 100 Meg ohm input but the standard was 10 Meg.

Sorry Asimov, I find that questionable at best.
For even in 1950 - 60' any 'industrial workhorse' like the tube-type
HP 410B used 100 Meg ohms input as a standard input
It was only when the DVM came on the scene that most inputs
appeared to drop to 10 Meg Ohms.


No, VTVMs designed for repair shops were 10 Meg on the AC ranges and
11 Meg on the DC ranges. The extra 1 meg was in the DC probe to reduce
loading in tuned circuits to minimize the effects of probing the
circuit.

You didn't see HP VTVMs in repair shops.

--
Former professional electron wrangler.

Michael A. Terrell
Central Florida