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Old July 30th 03, 05:54 AM
 
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castles wrote in message ...
I would like to build a set up for testing transmitting tubes. I was
thinking of just testing a couple of points. My power supply will have a
capability of 500 volts maximum at 2 amps. I would test a triode for
instance for cutoff and then I was thinking of going to the plate
dissapation value. I would do this short term so that the tube would not
need to have forced air cooling.

I am planning to sell some of my transmitting tubes and would like to
advertise them as having passed a series of tests. What tests would be
most meaningful?

Thanks for you suggestions, Don

++++ I recently built a transmitter tube tester. I made several
sockets ,4 pin 5 pin 6 pin etc for 811, 4-400/3-500, 813, etc.For
instance,to test 811 tubes, I would drop in the 4 pin socket,hook up
proper filament,set bias voltage as per tube data, set up for 811
tubes and test all I had .. I used about 1400 Volts on plate,had
adjustable filament voltage..I had var bias,var screen.. I tested for
emission by reading plate current..I worked out very well for matching
emission on several tubes ..I also applied RF drive ,usually at 14
mhz.using a standard ham transmitter..an old Heathkit is OK..anything
with adjustable RF power out.a soft tube will come up to about normal
and will then start to fall-off..A person could keep on hand a known
good tube for comparsion...good luck Harold W4PQW Ps: I sold my
tester after I finished testing all my tubes..