03-23-2008, 11:27 PM
Brian, Thanks for the video!! You most definately have one or more *microphonic* bad (still working tubes) in the set somewhere on the chassis. Tapping easily on top of each tube separately with a pencil while set is on should isolate the defective tube (s).I have found motorboating is usually a caused by a defective coupling-capacitor somewhere out to chassis ground , possibly one missing from the past before you restored the chassis? Doublecheck your schematic, possibly someone removed a cap before in a prior repair job and forgot to replace it? The antenna wire most probably needs at least 20' or so to do a good job. It is easy to *overload* the longwire antennas sometimes also by using too much length in these old sets!! You can try using a 250 pf (uuf) ceramic disc cap in series with your longer antenna wire at the ant term sometimes helps balance the outdoor longwires? Randal 
