[BC] Re: Collins 831F2 assistance needed

[Jerry Mathis]

Sounds to me like you started out with a bad 4CX250. The new one is OK, but
it is not getting any drive from the exciter. Check IPA grid circuit for
opens, including more bad resistors. Remember, visual inspection means
little in the case of carbon resistors. Measure!

--
Jerry Mathis

On 6/7/09, Gary Glaenzer <glaenzer at verizon.net> wrote:
>
> 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
>
>

-- 
Jerry Mathis