I found this under a table at a hamfest for half price... $10. I knew I could use the power transformer at least.
811A Linear Amplifier
I found this under a table at a hamfest for half price... $10. I knew I could use the power transformer at least.
It was pretty rough, missing a few parts, and the chassis was bent up.
The Barker and Williamson 851 tank coil was falling apart, mostly because of the deteriorating plastic supports.
I was able to soften the supports with a heat gun and straighten them.
I added an SWR bridge.
Starting work on the front panel. I wanted to be able to see the plates of the tubes so I installed a window.
One of the original 811A's had overheated severely at one time.
I decided to add a tuned input to the amp.
The RigExpert made it easy to tune the input bands.
Since I was putting in all this work, I went ahead and put in a PTT relay circuit, fans, and a standby bias to cut-off the tubes during receive.
Done!