[AMRadio] Too much HV

[Rob Atkinson]

The older MVs have _a lot_ of mercury in them compared to the ones
made near the end of production.  I have 866As from the late 60s and
you can't even see the mercury in them but it's in there because the
tube clouds when you heat it up.  But the earlier RCAs look like they
have 10 times more mercury.  That may make them more likely to give a
light show.

This is very important:  MVs _must_ be kept vertical.  If you move a
p.s. deck and turn it on its side with them in there or pull them and
bounce them around then you have to let them sit vertical for a long
time afterwards to make sure the mercury has settled back down in the
bottom of the glass.  Even if you let the filament heat up, if they
were recently turned upside down, you may have a problem.

73

Rob
K5UJ