02-16-2009, 09:52 AM
Hi Daniel,
In regards to the speaker and output transformer you can substitute using a pm speaker but with some modifications. The speaker in your radio has a field coil. It is used to create a magnetic field around a pole piece for the voice coil to work against. It also is used in the power supply as a choke to help smooth the dc voltage. Here is the schematic. http://www.nostalgiaair.org/PagesByModel...013233.pdf Part number 44 the 1140 ohm field coil is what you need to replace. You can do this with a power resistor (About 15 watts is as low as I would go) close to the same resistance +/- 20%. Usually better to go higher in my opinion. You can order one from many different vendors. Mouser is a good place. The output transformer I would use for a 6F6 ( about 7500 Ohms) is the Hammond 125CSE from Radio Daze ( prices have gone up since I bought one!). You can use the 5000ohm tap or the 10000 ohm tap for 8 ohms if that is what your speaker is. I think either one will work and sound fine. This can be a permanent fix if you want and you can't find the original speaker. You can mount this under the chassis kind of away from the other components. It will get hot. Maybe some of the other folks can add some more insight.
Hope this helps
Terry
In regards to the speaker and output transformer you can substitute using a pm speaker but with some modifications. The speaker in your radio has a field coil. It is used to create a magnetic field around a pole piece for the voice coil to work against. It also is used in the power supply as a choke to help smooth the dc voltage. Here is the schematic. http://www.nostalgiaair.org/PagesByModel...013233.pdf Part number 44 the 1140 ohm field coil is what you need to replace. You can do this with a power resistor (About 15 watts is as low as I would go) close to the same resistance +/- 20%. Usually better to go higher in my opinion. You can order one from many different vendors. Mouser is a good place. The output transformer I would use for a 6F6 ( about 7500 Ohms) is the Hammond 125CSE from Radio Daze ( prices have gone up since I bought one!). You can use the 5000ohm tap or the 10000 ohm tap for 8 ohms if that is what your speaker is. I think either one will work and sound fine. This can be a permanent fix if you want and you can't find the original speaker. You can mount this under the chassis kind of away from the other components. It will get hot. Maybe some of the other folks can add some more insight.
Hope this helps
Terry
