[BC] Collins 831F2 .... FIXED

[Gary Glaenzer]

Well, it turned out to be the 'driver tuning' capacitor (10-turn vacuum variable)

We changed it Sunday and now have peak (not 'dip') in Driver Ik and plenty of grid drive
to the final, plus Driver Ik is about 150 mA instead of 200

But am looking for a good HT-10 or similar to replace this ageing beast.........I feel our
luck is about to run out in the 'Resurrection Department'

HT-10, Z-10, BE-10, something a bit less 'ancient'

Thanks to all for your help on this one

Gary

From: "Gary Glaenzer" <glaenzer at verizon.net>

> found burnt 47-ohm resistor in 4CX250 screen circuit
>
>   changed it
>
>   it burned again
>
>   changed again, and changed driver
>
>   STILL no PA Grid current, but now have good (215 mA) Cathode current on
>   driver
>
>   'Driver PA Tuning' will not dip cathode current
>
>   no PA grid current