I was the sunday morning net operator in an ATC squadron in the '50s using 1154/1155. I have just always loved these radios,, but they have quirks Here are 2 simple things you can do to an R1155 to improve it:
1. Frequency stability: Replace the ceramic compression trimmers with Johanssons
2. SSB performance is spoiled by AGC pulling the LO. Just take AGC? off the mixer tube grid and contrive -3v fixed grid-cathode bias. I did that wirh a 3.3v zener.
If you want to do a bit more, I found some very cheap 560KHz ceramic resonators which I used within the existing IF cans to sharpen up the selectivity. I simulated proposed bandpass filter structures in FORTRAN? first to get nice flat top to the response of each can.
Paul ex-G3VEL now KX4GP
