Hi, I need to replace the audio transformer in my SX-28, it has an unbalance that is causing lots of hum. Part number is 55B009 (manual says 55B052) and on another 28 I have no markings. Probably any Hallicrafters receiver with a parallel 6V6 output will do. Is there a parts donor out there? I would appreciate contact. 73s, Skip W7WGM