[Test-Equipment] WTD: Help with old scope problem

[k4pf at juno.com]

 "Joseph Orgnero" <josepho at shaw.ca> wrote
>As for the HV, some other messages state that the 260 
is not suitable due to loading, unfortunately,
I don't have a VTVM for that purpose.

Hi, Joe

I'm afraid the poster recommending against the Simpson
for HV measurement is mistaken.  A standard VTVM has the same
input impedance on all ranges, 11 Meg Ohms.  A  Simpson 260 VOM
d.c. resistance changes with the scale selected,
at 20,000 Ohms/Volt (i.e. the meter sensitivity is 50uA).
At its 10V scale, the Simpson resistance would only be 200K,
which is much lower than a VTVM.  However, at its 5,000V scale,
the Simpson has 100 Meg Ohms resistance, about 9 times higher
resistance than the VTVM.  

73,
Ed Knobloch