[PhilcoPhan1936]

Wouldn't be in a terrific rush to replace the spkr. As you may know the spkrs for the 20,21,70, and 90 (all the same style) suffer with arthritis (stiff paper cones and spiders) and the fidelity is not very good. I had a 20 on the bench a couple of years ago that I disconnected the output transformer from the voice coil and connected it a modern PM spkr. I was surprised the hear how good it really sounded.
On your set It looks like it has the original output transformer, I'm thinking that any of those early spkrs will work but some are set up for push/pull output tubes (two tube instead of one). The difference being the output transformer. The P/P spkrs will also have 4 wire where yours has3. If you find a 4 wire one you can change the output transformer to your old one and your all set.

Terry

Terry,

I believe the speaker that is in there now is a PM speaker, with a choke on it. There are only 2 wires going to the speaker. I'll have to investigate and make sure any mods have been done properly, and decide if I want to leave as is, or return it to a more original speaker. Thanks for the info. I was also pointed to the Tech section on the Philco Website that covers the speaker issues on this and similar models. I have some reading to do!