As I mentioned on one of these lists, I found a 1930's transmitter at the Butler hamfest. At first, I thought it was homebrew, but looking it over, it's definitely commercial or a kit. It's built to high standards and there's no extra holes or poor parts choices or unprofessional work of any kind. But so far I am unable to identify it.
It was designed to have 3 19 inch rack panels--PS, exciter and final (bottom up) But the PS is missing. I guess if something has to be missing, that would be my choice since I have a good stock of power supplies and parts for same. The TX is all black wrinkle, chasses panel and rack. The rack looks to be the original, open-back rack. The final deck has a socket for a single tube with the large, twist-lock base and 2 plate-cap-size connections for plate and grid caps. Not many tubes fit that description, so I am thinking maybe an 810 goes there? The Eimac tubes are out because they used a pin for the grid--not a full-size plate cap. The final deck has a filament transformer (I haven't checked the voltage yet) and 3 large coils--one is copper tubing, one is a plug-in type with center link that looks something like the old B&W "B" coils and the third one is on a large EFJ ceramic coil for under the chassis. Two of the 4 steering-wheel type knobs on the front are labeled ANTENNA so I think the final incorporated some sort of antenna tuner. The other two are labeled PWR AMP GRID and PWR AMP PLATE. The variable caps on the final deck are all Cardwell. The final deck has 2 meters, Triplett 0-100ma and 0-300ma. The exciter has a 47 xtal oscillator driving an 807 buffer and what I assume should be an 807 output tube (but it came with a 5933 in that socket). It has three 4-pin plug-in coils mounted on standard Hammarlund 1.25 inch forms, one in front of each tube. The exciter also has 2 meters. One is a Triplett 0-100ma that can be switched into 5 different positions of the exciter circuit. The way this switch is implemented is one of the things that makes me think this thing is commercial--each connection is implemented on a 1/4 inch jack and the wires from the switch go to plugs plugged into each of these jacks. The other meter is a Weston 0-600V meter that was probably a repair job--it has multiple scales on it and looks like the meter from an old VOM. The 3 variable caps on the exciter deck are all Hammarlund. They have knobs with metal skirts with dial scales on them and are not labeled. In general, the wiring is simple and high-quality. Mica TX caps are used throughout, along with National RFCs and EFJ parts in all the right spots. All the parts are name brand. So that's the whole story. If you think you might be able to help ID this rig and you'd like a look at it, please send me an e-mail and I'll send you a picture. I've already checked Moore's book and it's not in there. The next step is to go rooting through all the magazines but maybe someone will recognize it before I have to do that. Anyone? 73, Don Merz, N3RHT ______________________________________________________________ AMRadio mailing list List Home: http://mailman.qth.net/mailman/listinfo/amradio Partner Website: http://www.amfone.net Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net
