Many Ne bulbs have minute amounts of radioactive material in them to
stabilize the firing point. As the radioactive emission rate decays, the
bulbs become erratic. Put in new bulbs, if you can.
Best,
-John
Christian A Weagle wrote:
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Good morning,
I have a 419A Nulling Voltmeter that I just finished replacing all the
electrolytic capacitors in. This cleared up my 'after warming up no
operation' problem. However, I also had to really have my way with
both the chopper freq adj and neon current adj pots to get them to
fire _something_ like reasonably. I can't get the frequency to be
correct (too slow by close to half), and the waveform is pretty
distorted over most of the range, and just _somewhat_ distorted over
the rest. This makes me think I probably need new choppers. I assume
these are unobtainum.
1. is my logic sound, or is there more likely a problem with the
driver instead?
2. what will a somewhat slow, distorted chopper waveform do to the
correct operation of this otherwise-excellent meter?
Thanks very much!
