Can't help it if you know so much more than the rest of us! ;-)
It's been at least 10 years, and I have a '301S that I've slowly been bringing back from the dead.... It now receives fine, but basically no power out. Perma-project status, ya' know?
As for 9 MHz filters, I ended up putting a Inrad filter for a '301 (CW/500 Hz) into a Hallicrafters SX-146 receiver (AFAIK, the only piece of Halli gear that used a 9 MHz IF.? There was an AM filter for it, but it was exceedingly rare, and the Inrad filter was on closeout.
73,
Paul
KA0JQF
