|
Title: Gross TX Restoration - Jefferson Transformer Info Needed Post by: W1UJR on April 29, 2009, 08:46:42 AM Hi fellows,
I'm finishing up the modulator section of the 1934 Gross transmitter but have come across a bit of a problem. The low level audio xformer, a Jefferson model 467-414, appears to be wired in incorrectly. I think that this may be a more recent replacement, as it does not appear to be from 1934. I'd like to get a spec or data sheet for the unit, any suggestions? Failing that, do you fellows have a suggestion for testing the unit, audio sig generator and scope ok? From my reading of the schematic, it appears that the xformer may actually be wired backwards, with the center tapped primary windings connected to the grid of the 57 tube, and the secondary connected to the input of the carbon mic. Transformer info: Jefferson transformer part # 467-414 Also stamped "30790" on the winding covering. Photo of the unit in question at the left center of this pix -->> http://gallery.me.com/brucehowes#100155/DSC02500&bgcolor=black Thanks! Photos of the process are here -->> http://gallery.me.com/brucehowes#100155 I'll get it put on my website later in May. (http://gallery.me.com/brucehowes#100155/DSC01940&bgcolor=black) Title: Re: Gross TX Restoration - Jefferson Transformer Info Needed Post by: Opcom on April 29, 2009, 10:45:24 PM pretty rare. This fellow might have a lead on transformers of the Jeffersonian persuasion - he has a historical page: AMfone - Dedicated to Amplitude Modulation on the Amateur Radio Bands
http://www.roger-russell.com/jeffers/jeftran.htm |