I have the TV7D/U version myself and love it!
One thing to be aware of with Hickock testers and most others as well, is that
the power transformer is rated at about 100Vac input so as to allow the line
adjust control with a series reostat. When testing any high heater current
tube, 6550, etc there is quite a strain placed on the transformer
if the tube is left in for burn in purposes. There is also the voltage drop
across the line adjust pot that increases when (Test) is done. The filament
transformer in my Mil TV2
fried from just such a problem after I had over compensated the adjust control
to make up for the voltage drop caused by a strong tube left to burn in for a
few minutes.
Most testers state to make the test quickly after proper heat up time. If you
look at the transformer ratings for these testers the heater windings current
ratings are barely
adequate for some of the larger power tubes.
Anyway I always use a small variac to set the line adjust and turn the control
on the tester full up thereby eliminating the series reostat and associated
voltage drop.
An AC ampmeter mounted with the variac also lets me see
just what the overall draw is. Much more consistant tests that way and safer
for the tester. Just don't forget to turn down the line adjust if plugging in
direct.
Bill,
KB3DKS/1
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