[Heathkit] TT1 Tube Tester Issue

[Gary H. Harmon, Jr.]

The Hickok uses 60Hz line signal to excite the tube grids for
transconductance testing.  They just step the voltage way down from the
transformer in the tester.  Simple and effective way to get ac voltage to
the grids.

 

On the TT1 there is a built in oscillator circuit (2A3 tube) to do this and
the frequency is between 6K-8K HZ.  I strongly suspect that therein lies the
issue with the TT1.  That would explain the low Gm readings and a lot of
other things if this circuit is not working optimally.  On rectifier
testing, the test circuits are the same between the Hickok and TT1 and that
would explain why rectifiers tested good on both sets.

 

Anyone have this problem before?

 

Gary H. Harmon, Jr. - K5JWK - HAM Radio and ATARI Archaeologist

6003 Archwood

San Antonio, TX 78239-1504

(210) 657-1549 <home>

(210) 884-6926 <cell and text>

(210) 657-1549 <FAX with prior notification>

gharmon at idworld.net

 

"Retirement = Every day is a Saturday except Sunday"

http://www.grissomroadcoc.org