09-10-2020, 10:34 AM
It is kind of a primitive circuit. The older sets (70) used two tubes to perform the mixing duties. Seems like there would be some interaction between osc frequency and the peak adjustment of the 1st IF. The 36 tube (tetrode) needs a suppresser grid but such was the technology in 1932. The generation sets used the 39/44 a full fledged pentode.
When my pals were reading comic books
I was down in the basement in my dad's
workshop. Perusing his Sam's Photofoacts
Vol 1-50 admiring the old set and trying to
figure out what all those squiggly meant.
Circa 1966
Now I think I've got!
Terry