OK, how about that tuner?
As mentioned earlier, the mixer is on the mains chassis. There is also no active RF front end.
The only active device on the tuner is a type 76 tube used as the local oscillator.
It is continuous with three ganged capacitors. Tuned antenna, mixer and Hartley VFO for the LO.
Those coils are wound next to each other on a common form for coupling.
Dead simple and badly radiates the LO back through the antenna!
Darryl to the rescue once again
Here's the schematic from the original "A" version.
Note the use of an experimental A-305A tube. Mine is missing, but a 6D6 may work well enough.
Later revisions used a rotary switch 6J5 and 1852.
Big thaks to Dave AKA "streetmechanic14" for this photo
Very similar to the Meissner design.
I'm going to experiment with a ganged cap salvaged from a Hallicrafters shortwave radio with similar range to the original.
Not necessarily going to be the final tuner I use in the set, but I figure it will be fun to try and get something going.
Darryl also kindly identified the parts in the photo using designators from the schematic. This will be a big aid.
L1/2/3, L45 and L4 are the coupled coils wound on a phenolic form.
I'll also examine one in person at the Early TV museum soon.
