VTVM

[Mike Morris]

There was a long comment thread here a while back on
this very topic and one point made was that if you look
at the schematic very carefully you will find a place
where you can remove a jumper on the function switch
and replace it with the 1 meg resistor and the
existing function switch will switch it in and out
automagically.

Towards the end of the comment thread the point was made
that the 1meg resistor was there to isolate the circuit
under test from the capacitance of the cable and of the
meter itself.

So I guess if you want a piece of test equipment that
works properly you'll need to take a cigar tube, a mini-
slide-switch (from Radial Shaft) and a 1meg metal-film
resistor and make up a probe.
Mine isn't pretty but very functional until I find a
proper probe.  It is made of shielded antenna coax,
has a mini-banana jack (again from RS) on the active end
and the actual probe is a matching plug with an inch of
solid wire (a scrap of #14 from rewiring an outlet)
sticking out of it as the actual test probe.  If I need
to get into a cramped corner of some equipment I can bend
it as needed, then straighten it out, and if it breaks
I can unplug it , clam it into the bench vise, and fix it
with a soldering iron and a replacement piece of wire.

Mike

At 09:16 AM 02/02/2001, you wrote:
>Re: Probes for Heath VTVM.  At the risk of offending the purists among
>us, a person could install a mini-switch on the panel and switch in a 1m
>resistor that way. A low resistance contact would be preferred. ( Sounds
>too simple, what did I overlook?) Fred W7PRV
>
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