08-03-2014, 02:59 AM
Had a day of frustration today. I began to chase little things under the chassis. For one thing the bass control was not working, and there was more of an AC hum than any newly recapped radio should have, so I began to poke around. Soon I found the problems, and began to correct them, or so I thought. When I fired the radio up again... nothing... just a hum. I began to trace circuits visually, and was surprised to find that my Rider's schematic shows a 6SQ7 where my radio has a 7B6, and on the inside sticker of my radio you can see where they blacked over the old number and printed 7B6 below it. Also, the 7B6 is oriented exactly 180 degrees out from the 6SQ7 in the Rider manual. well, needless to say this led to a WHOLE lot more circuit tracing, and consulting the RCA receiving tube manual. found that, although the tubes were different and oriented differently, I had put the right caps to the right places since I had done it all by eye in the first place. Still, checked and rechecked things with no luck. Finally pulled out my signal genrator and began to use it. soon found the problem. One of the loctal tubes had come loose in my turning the chassis over and back. well... having done all the triple checking, I am now pretty well confident that the radio is close. AM and SW are working VERY well now on just the built in antennas, and the sound is GREAT but FM is still a devil. I get 2 FM stations weakly. and just a hint of a few others, but nothing really distinguishable. So the hunt continues...