[Radioroslyn]

The plot thickens. After doing some troubleshooting I was not getting a clear idea of what is causing the problem. Steps taken, added shrink tubing to the somewhat tattered wires where they exit thru the metal output transformer cover. Was thinking that perhaps there was some sort of arcing but true be told everything back there is at +300vdc or so and there is no ground/B- connection so arcing is a long shot. Yielded no change. Next was the opt, maybe so shorted turns? Wired in a new Hammond 125E. Played ok but didn't solve the mystery. Finally I grabbed a 12" industrial strength spk and no more popping!
At this point the speaker seems to be the problem. I gave Rich a call @ Sound Remedy and described my problem he apologized that what was happening was the voice coil was bottoming out against the bottom of the pole and that's what is causing the popping/buzzing. During the recone he had set the coil too low. He gracefully offered to reset the distances and send it back so I'm very Happy! And would highly recommend Sound Remedy for speaker repairs. Yes it would have been perfect if it didn't have a problem but I've always impressed w/a shop that stands behind their work.
I didn't realize that when he does the recone not only is the paper cone replaced but the voice coil and is converted to an internal spider rather than the old school spider w/the screw in the center. It's all good.
That little 8" speaker gets a real workout when the tone switch is in the mellow position!!!! That cone is MOVING!!

Mystery solved!
Obtw one thing I'll mention in passing since I'm on a speaker tear (little pun) the Hammond transformer works ok BUT the E is a bit bigger physically and may present a little challenge to mount. The other point is the original Philco transformer sounds better (to me) as the Hammond seem to rolloff some of high frequency response. It's not horrible and if you didn't have an original to compare it to you probably woundn't notice, but I do.