Help needed identifying this radio - Printable Version
+- The PHILCO Phorum (https://philcoradio.com/phorum)
+-- Forum: Various and Sundry Categories (https://philcoradio.com/phorum/forumdisplay.php?fid=37)
+--- Forum: Other Radios (Non-Philco) (https://philcoradio.com/phorum/forumdisplay.php?fid=12)
+--- Thread: Help needed identifying this radio (/showthread.php?tid=6496)
+- The PHILCO Phorum (https://philcoradio.com/phorum)
+-- Forum: Various and Sundry Categories (https://philcoradio.com/phorum/forumdisplay.php?fid=37)
+--- Forum: Other Radios (Non-Philco) (https://philcoradio.com/phorum/forumdisplay.php?fid=12)
+--- Thread: Help needed identifying this radio (/showthread.php?tid=6496)
Help needed identifying this radio - BrendaAnnD - 04-20-2013
Nice little set, but nothing to ID it so I can't look up a schematic. Chassis says Model 80 M.
RE: Help needed identifying this radio - Arran - 04-20-2013
Is it a three or four tube AC/DC set with ballast? If so it could be a "Plant A" set from Chicago, those have a colored decal on the back of the chassis. Plant A also made some small AC sets around the same size.
Regards
Arran
RE: Help needed identifying this radio - Radioroslyn - 04-22-2013
You need a schematic for this?? Looks to be a dept store set from the early 1930's. Even with a name on if a lot of times there is no info for it. Most are pretty simple affairs just having the bare bones of tubes and parts. Usually just have a rf amp,det, audio output, and rectifier. Have seen both AC/DC and just AC models. Here's an odd one I picked up a few yrs back.
http://www.flickr.com/photos/53710524@N06/5704327973/in/photostream
GL
Terry
RE: Help needed identifying this radio - BrendaAnnD - 04-22-2013
Kind of a cool looking old bugger.
If this thing hadn't been so cobbled up, I wouldn't need a schematic. As it sits, I'd be building pretty much from scratch. :-/
RE: Help needed identifying this radio - rghines1 - 04-22-2013
Have you tried the online radio database at grillecloth.com. The tube complement may give some leads.
http://www.grillecloth.com/sylvania/tubelist.php
RE: Help needed identifying this radio - Arran - 04-22-2013
As I can recall I repaired a Plant A set, one with four tubes plus a ballast, by using a schematic from a Popular Science or Mechanics Illustrated magazine from the 40s, it did not have a model number that I could find. The schematic was a DIY project for people that wanted to build their own radio but was almost identical to what I found in the Plant A set.
Regards
Arran
RE: Help needed identifying this radio - BrendaAnnD - 05-04-2013
GOOD NEWS, everybody!
I got in the rectifier and ballast for this beastie. Using a basic schematic I reconnected everything as it should be, and got started troubleshooting.
First off, I knew that there were issues with the antenna coil, since the primary had pretty much fallen to pieces. I used a generic coil from AES to do the testing.
First up, brought it up slowly on the variac. Everything was looking good, till the rectifier shorted and took itself out. Investigation brought no issues that would have done this externally, so I figure it must have been the tube itself had some sort of internal injury (one side of the tube plates got red hot, but the other, which was in parallel with it, did not). Fortunately, I had bought several spares for stock. Replacing the tube brought all voltages up nicely, with no problems noted.
There was no audio. I found that a Micamold resistor in the cathode circuit of the 43 output tube (also is the screen supply for the 6J7) was open. It appears from the schematic I have that the resistor's value should be around 500-600 ohms. I paralleled two 1K 2W resistors and placed them in circuit, and the audio came to life. There were still RF issues.
I could get RF through the 6J7 (2nd RF/Det) if I touched the grid cap. This was intermittent, cleaning the tube socket cured that. No RF could be forced through the 6K7 (1st RF). I subbed in a new tube, and suddenly there was music coming from the radio! At first, it was pretty much just one station, my inhouse transmitter, across most of the band. Not too unusual for a two stage TRF. I did a quick alignment, including the "rocking" to get the low end to track, and now it gets stations up and down the band, and actually does a darn good job of it!
Tomorrow, I'll clean up my temporary connections, put in permanent replacement 'lytics, and try to fashion a new dial cord pulley for the tuner shaft (the one it had was missing when I got it, and as a result, the dial did not track properly). I figure I can chuck up a shaft extender and use a rat tail file as a lathe. Isn't trial and error fun?
RE: Help needed identifying this radio - TA Forbes - 05-04-2013
That was a nice bit of troubleshooting, Brenda!
Color me impressed!!
RE: Help needed identifying this radio - BrendaAnnD - 05-17-2013
Wow... well, I now know who MADE this thing, thanks to "Identify this beauty" thread. When that radio was pointed out as being a Majestic, I went to Radio Attic to see if I could find it. I didn't find that one, but lookie here:
http://www.radioatticarchives.com/radio.htm?radio=7381
Still can't find any literature on it, though. There's still one problem I'm working on with it: the pulley that fits on the tuner shaft is missing. I'm trying to fabricate one using a shaft extender. Wish me luck.
RE: Help needed identifying this radio - Arran - 05-18-2013
The brass plate seems to say "Majestic International", it is also in a different script then Grigsby Grunow or Majestic Radio and Television would have used. This isn't to say that the latter company could not have built it but it just wasn't their style to use a generic dial like that. You sometimes run into similar sets with names like "Freshman" or "Silver" or even "Grebe" on them but it was really just a form of badge engineering, sort of like the Chinese ghetto blaster with the name "Philco" or "Electrohome" on it.
Regards
Arran