Trash Or Treasure?

[Elias Graves]

Couple of old radios I scored. Worth messing with? Convertible to guitar amps? Raid for parts and junk em?











EG

[paggerman]

You're right up my street with this. Without further information it looks like you have a rectifier, two valves for tuning in AM stations and three amplifying valves. Maybe a twin diode acting as gain and PI with two power valves (6v6?). My MO is to rip out everything except the PT, heater wiring and sockets. In your case leave in the Opt as well. Then look through a bunch of circuit diagrams to see what's appealing, mix things up a bit and see what comers out. If Im right about the 6v6 output, look at the Gibson GA20 and GA25 circuits. They have a pentode input stage and sound really cool. So what if the secondary voltage is different to the spec - it will still work. Or work with the valves you have. Use google to find an amp that matches what you have e.g. "6v6 6sj7 amplifier schematic" and work from the results to find something appropriate. Draw a circuit diagram to suit your resources. For example, my current project is a hybrid of the Gibson GA20 and GA25 amps. The PT voltage doesn't match, and the rectifier is a 5v4 instead of a 5y3, but so what? It will be my amp and will sound so much better for it! Good luck, I hope you cam make something of this.

[Firechief]

You have a radio with a "tuning eye tube" google it, they are kinda cool. And the transformer looking thing on the back of the speaker is a "speaker field coil" here is a discription ---- This takes the place of the permanent magnet in creating the fixed magnetic field. Advances in technology of permanent magnet manufacture have made field coil speakers mostly obsolete. Typical field coil DC resistances are in the 1000 to 5000 ohm range. They are made of thousands of turns of very fine wire and were usually wired either from B+ to ground or in series with the B+ feeding the amplifier to act as a filter choke. ----
This means that you will probally not be using that speaker, but it looks pretty crusty anyway. The most usable item is probally the power transformer. Next mabe the tubes. Look em up!

[JHow]

Actually, I think the "transformer thing" in on the speaker basket in pix 1 and 3 is in fact an output transformer. The field coil will be the extra wires running to where you would expect the magnet on a PM speaker.

You didn't show us the cabinets. Are they trashed? I'd probably tend to vote for "restore radio" rather than "make into guitar amp". You probably aren't going to get too many sections of audio amp out of these.

[Elias Graves]

The cabinets are pretty trashed. My wife's grandmother had a dog that apparently liked to hike his leg on them. Yippee.

I found an antique radio club here in town and they are pretty excited to see them. I'm taking them to their next swap meet to try to trade them for something more useful to me. Tubes or speakers maybe.

EG