Sunday, November 6, 2011
This is what happens to an FAA amp when the RF feed opens
These are very difficult to find as replacement parts, but since I have a sheet of Kapton of the same thickness I made a new one, installed it and tested the amp. Seems to work fine. Sure beats buying a new cavity if they are even available.
I also convert these amplifiers to run on a 4CX250B instead of the 8930. The 8930 is the same as a 4CX250R which is a 4CX250B with more rugged structures and a much larger anode assembly. This combination allows the tube to withstand more vibration than the 4CX250B and it will dissipate heat better.