Air King Model 2207

[nocusr]

What a coincidence - I purchased an Air King 2207 on eBay Dec. 12!

I've been searching for a schematic, as I thought I was mising a tube. Actually, I'm missing the ballast. The number (M55HG) is stamped on the chasis, but as the other numbers are on the respective sockets, I dismissed the number as a some random, possible production related number. I however, say nothing denoting 25 Hz operation. So, thanks for your help Johnathan.

Did you ever find a schematic? If not, and I'm successful, I'll let you know. I belong to a couple of antique radio clubs, so I'll start looking. In the meantime, I'll try to figure out the wiring and a way to replace the ballast (with either a capacitor, diode or BIG resistor), to get the required (apx) 60 volt drop.

While it may not be a superhet, some TRFs can be really hot, and they sound alot better.

[ddk375]

I just picked up a Model 2206 (the 60 cycle/hz version) from an estate sale. It took only minimal recapping to get it working, and it performs surprisingly well for a simple TRF. Mine also uses a glass ballast, which doesn't seem to produce any more heat than the rectifier or output tube. The schematic is in Rider Volume IX, page 9-12.

David