[Phlogiston]

C-3 form around 1924. Video of radio in operation:

http://www.russoldradios.com/blog

[KCMike]

Really neat one there Russ. Sounded good for such an oldie. Interesting how the air coupling of the coils worked. Thanks for showing that part also.

[Eliot Ness]

That sure is the earliest Wurlitzer I've seen and +1 on those neat coils.  Thanks for sharing the video!  

[Phlogiston]

Updated with some interesting comments from Matt on ARF.

[Phlogiston]

Really neat one there Russ. Sounded good for such an oldie. Interesting how the air coupling of the coils worked. Thanks for showing that part also.

You can see why they later just put the windings of the transformers on one form close together. But in this radio that is the most effective means of volume control - better than using the filament voltage. It would be like variable antenna coupling in later radios. Instead they became fixed with a variable resistor on one winding or the other - not better, just easier.

[Arran]

Spider web style coils, that's a very interesting take on a variocoupler. If you think about it it pretty much does the same as a later volume control, it varies the gain by varying the coupling. I can't recall seeing such coils in a factory built set before, though there were probably other sets sold that did, I think the last set I saw with spider web coils was a home brew, and I think that they were fixed.
Regards
Arran

[Phlogiston]

I have more with that type of coil/transformer. One other has the variable coupling feature (it moves). I can show some of them if you like.

[Ron Ramirez]

Really neat one there Russ.

I'll ditto that. Enjoyed the video as well.

[Phlogiston]

Thanks Ron.

It really is a pretty good radio.

[Kenneth F. Besso Jr.]

Excellent ,,beautiful,,,,WOW,,,