On Mar 24, 9:27*pm, Phil Hobbs
wrote:
On 3/24/2013 8:45 PM, cjt wrote:

On 03/22/2013 09:43 PM, wrote:
snip
The little HF LCD display multimeters seem to have pretty high input
impedance, but I've never actually tried to measure it. *Certainly
much higher than the old Simpson multimeters.

The "Simpson multimeters" were generally VOMs rather than VTVMs, no?)

I think those were the most common. *In my lab I have one Simpson VOM
and two Simpson VTVMs.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics

160 North State Road #203
Briarcliff Manor NY 10510 USA
+1 845 480 2058

hobbs at electrooptical dot nethttp://electrooptical.net

But there is another factor here that no one has considered. The OP
may be used to working with an old tube type VTVM of the kind he no
longer has and would be very comfortable with a similar replacement. I
still have and use my RCA Senior Voltohmyst that I built in 1962. And
it still keeps good time. Lenny