General Radio Vacuum Tube Bridge

This is what we use for special testing and matching of power tubes.   Plate power for this bridge is provided by a Kepco 1520B power supply 0-1500VDC @ 200ma.  Screen power is provided by a Kepco 605 power supply which supplies 0-600VDC @500ma and a negative bias voltage of 0-150VDC.  Also used is an HP 651B oscillator, HP 5245 counter, Dytronics 717S AC Null Detector, and Krohn-Hite UF-101A Amplifier.   With this setup, I can meausre transconductance, plate resistance and amplification factor to 3 signifigant digits.  Most importantly, I can match output tubes at the voltages they operate at in the circuits they are used in.  This assures a good match.  Also, I can test tubes such as 211's, 845's etc. that cannot be tested on a standard tube tester.

This tester is used at our testing lab and is not for sale, sorry.


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