01-27-2017, 11:41 AM
I have restored two Philco 19 cathedrals and one 89. There are pretty much all the same radio except the Model 19 has the shadow meter.
On each one I had to at least rewind the oscillator tickler coils. The 36 tube in this design has been know to be very temperamental, and after considerable struggle I got the all radios to work across entire the AM band.
Last week, I was playing one of the Model 19s, and son-of-a-gun, the oscillator was starting to cut out below 1000 Khz. I tried a couple different 36s, even new ones, and it wasn't making a difference. It was working at one time! I finally decided to make the change from the 36 to the 77 tube as described in Ron's tech tip #42 on the Philco Repair Bench.
http://www.philcorepairbench.com/tips/svctip42.htm
I thought I'd pass it along that the mod works great! The radio seems to perform stronger than before and doesn't cut out at all as I tune across. The hardest part was installing a different tube socket. The 5-pin Philco socket for the 36 has mounting holes positioned that I don't think you will ever find on any replacement 6-pin socket.
Drilling holes in that Fort Knox-like Philco chassis in exactly the right spots for the new socket wasn't easy. But I am glad I made the change, and wouldn't hesitate to do it on a future restoration.
Mark K8KZ
On each one I had to at least rewind the oscillator tickler coils. The 36 tube in this design has been know to be very temperamental, and after considerable struggle I got the all radios to work across entire the AM band.
Last week, I was playing one of the Model 19s, and son-of-a-gun, the oscillator was starting to cut out below 1000 Khz. I tried a couple different 36s, even new ones, and it wasn't making a difference. It was working at one time! I finally decided to make the change from the 36 to the 77 tube as described in Ron's tech tip #42 on the Philco Repair Bench.
http://www.philcorepairbench.com/tips/svctip42.htm
I thought I'd pass it along that the mod works great! The radio seems to perform stronger than before and doesn't cut out at all as I tune across. The hardest part was installing a different tube socket. The 5-pin Philco socket for the 36 has mounting holes positioned that I don't think you will ever find on any replacement 6-pin socket.
Drilling holes in that Fort Knox-like Philco chassis in exactly the right spots for the new socket wasn't easy. But I am glad I made the change, and wouldn't hesitate to do it on a future restoration.
Mark K8KZ
