Re: Tektronix 465 No Trace, No Dot


 

Simpson 260 VOM's provide 20 kOhms/volt sensitivity on all DC volts
ranges, as the basic meter movement is 50 microamps. A Simpson 260 with
a 5 kV range therefore provides circuit loading of 100 megohms. Many
(most?) of the 260's do not have a 5 kV range.

Mike N4MWP

On 04/12/2016 06:10 AM, Malcolm Hunter malcolm.r.hunter@...
[TekScopes] wrote:

On 12 April 2016 at 07:13, w7qed@... [TekScopes] <
TekScopes@...> wrote:

Then I got brave and hooked up my Simpson 260 from chassis to the
"-2450"
test point (TP1423 I believe). On the 5kv range it hardly moved. On
the 500
volt scale it went about half way up. On the DMM this measured
-490V. Now,
it's 11 pm and I know better than to keep at it this evening (as
much as I
want to). Any pointers? I will review the cathode voltage circuits
tomorrow
and take another peek tomorrow evening.
​What's the impedance of the meter? It's most likely that it's
shorting out
the HV​. You need to use a HV probe ideally with gigohm impedance.

Malcolm

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