" bravely wrote to "All" (08 Apr 05 04:50:09)
--- on the heady topic of "VTVM versus new DVM"

bo From:
bo Xref: aeinews sci.electronics.repair:45265

bo Hi,
bo I am doing a tune up on an old turntable I have and according to the
bo service manual I need to make measurements with a VTVM (vacuum-tube
bo voltmeter). I own a Fluke 111 DVM, is there any reason why this can
bo not work in place of the VTVM.


JR,

The requirement to use a VTVM was given because its input is 10 Meg
ohms or more and so it wouldn't affect the circuit voltages. A DMM
typically meets a 10 Meg ohm requirement and is equivalent to a VTVM.
Rare VTVM's used a 100 Meg ohm input but the standard was 10 Meg.

A*s*i*m*o*v

.... 'Keep the smoke inside.' -- 1st Rule of Electronics.