[BC] FM10K

[Alan Alsobrook]

On 11/10/2013 5:12 PM, Tom Taggart wrote:

> What I have now is IPA trouble. No drive to final, the transmitter
> will come up, but with a boatload of PA current, and no output (have
> Bird in line).  Only small amount of IPA cathode current.  Outboard
> exciter drives 4cx300A IPA which drives the final.  Thought the IPA
> might have gone--been in the transmitter since July 2012.  However,
> same symptoms with new IPA tube, Eimac, bought 2 years ago when they
> were being discontinued.

Without more specific info hard to say. Best advice start with what is 
working and work towards what isn't working.

Given that the exciter went full tilt, check everything very closely on 
the input side of the IPA.

I'd keep the PA out of the circuit until you can get the IPA back up. 
The PA drawing high current without drive is not a good thing.

-- 
Alan Alsobrook CSRE AMD
aalso at bellsouth.net