10-21-2013, 11:36 AM
Very kewl!!! Well here's the service info for your set.
http://www.nostalgiaair.org/PagesByModel...014012.pdf
If look over by the speaker you will see four connections. I don't know how they terminate perhaps in a four pin plug. Anyway the speaker voice coil connects to the output transformer secondary. One side of it is connected to the chassis/ ground. The original speaker had a very low impedance VC like 1.25 ohms. The closest thing you'll find now days will be a 3 or 4 ohm job. Don't use a 8 or 16ohm the mismatch of impedance will cause lower volume and distortion. You could use two 3 ohm speakers in parallel. That would get you down to 1.5 ohms which is good.
The connection from the battery to the field coil #48 you won't have that on your replacement spkr and it doesn't need to be connected like it would be on an AC set. So you can leave it alone.
Now there is the tone control. That would be the terminal that connects to pin 2 of the #42 tube and the output transformer. I don't know if your set has the tone control built into the radio chassis or it is part of the control head. If it isn't it may play OK without it. Or it may oscillate to cure that a small cap from the plate pin (#2) of the 42 tube to the chassis. Something like a .005mfd@630v will work fine.
I'm assuming that this set has been service with all of the paper caps replaced and the electrolytes. All of the out of tolerance resistors have been replaced. Without doing this is like gassing up a 70yr old car and taking it for a spin on the turnpike.
GL
Terry
If you would like to get a better/much shaper copy of the data for your set send Chuck S a note. He can hook you up.
http://www.nostalgiaair.org/PagesByModel...014012.pdf
If look over by the speaker you will see four connections. I don't know how they terminate perhaps in a four pin plug. Anyway the speaker voice coil connects to the output transformer secondary. One side of it is connected to the chassis/ ground. The original speaker had a very low impedance VC like 1.25 ohms. The closest thing you'll find now days will be a 3 or 4 ohm job. Don't use a 8 or 16ohm the mismatch of impedance will cause lower volume and distortion. You could use two 3 ohm speakers in parallel. That would get you down to 1.5 ohms which is good.
The connection from the battery to the field coil #48 you won't have that on your replacement spkr and it doesn't need to be connected like it would be on an AC set. So you can leave it alone.
Now there is the tone control. That would be the terminal that connects to pin 2 of the #42 tube and the output transformer. I don't know if your set has the tone control built into the radio chassis or it is part of the control head. If it isn't it may play OK without it. Or it may oscillate to cure that a small cap from the plate pin (#2) of the 42 tube to the chassis. Something like a .005mfd@630v will work fine.
I'm assuming that this set has been service with all of the paper caps replaced and the electrolytes. All of the out of tolerance resistors have been replaced. Without doing this is like gassing up a 70yr old car and taking it for a spin on the turnpike.
GL
Terry
If you would like to get a better/much shaper copy of the data for your set send Chuck S a note. He can hook you up.
