To Field Coil or Not to Field Coil

[Blueboozer]

I just invested a months pay in a 1940’s Sparton 7-46 PA ($60). My original intention was to steal it blind and see what kind of amp I could build with 2 6F6’s in push pull configuration and what I think are 7A7 pre’s (I can still do that and check out the tones). But after firing it up I think I might just restore it. It makes noises and all the tube filaments are lit. It has an old field coil equipped 10” speaker in it.  So my question is, should I go with the current speaker or try to find an OT to match the 6F6’s and go with a more modern speaker?

I think I’m going to turn it into a twilight zone radio. Wire an audio source that plays big band and use it to puzzle the kids. “It’s stuck in WWII and only plays Big Band”

[PRR]

Only you can answer those questions.

That's a particularly nasty "phase inverter".

[Blueboozer]

That's a particularly nasty "phase inverter".

I was assuming that was the function of the 7B6. Not what I’m used to seeing. Will take some noodling…

[Blueboozer]

 

[Blueboozer]

Shows my ignorance. A phase inverterless push-pull amplifier.

I didn’t know there was such a critter.

Found this in the DIY forum - looks strikingly familiar

[Willabe]

I think I’m going to turn it into a twilight zone radio. Wire an audio source that plays big band and use it to puzzle the kids. “It’s stuck in WWII and only plays Big Band”