I never did figure out why. ?The receiver (11-tube and late s/n) is still working fine.
On Sun, Dec 29, 2024 at 8:10 PM, Dave W7GZ via groups.io <
w7gz@...> wrote:
Steve, did you ever figure out this behavior? My R-4A BFO has identical symptoms to yours. I fixed it by adding a 1K resistor to pull down the Vcc on Q6, but why does the transistor oscillate at 6V but not at 10V Vcc? I didn't check every component around Q6, but they don't look cooked. It was puzzling to have to park the mode switch halfway between AM and SSB to get BFO.
?
Dave
