[BC] Collins 831F2 assistance needed

[RichardBJohnson at comcast.net]

The 4CX250 socket has a built in screen bypass capacitor. It is probably shorted. That
would take out the series resistor.

Cheers,
Richard B. Johnson
Book: http://www.AbominableFirebug.com/

----- Original Message -----
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

  changed final, same readings

  any thoughts ?

     Gary