09-24-2020, 01:25 AM
For future reference, in case someone else finds this thread and is confused, I came across yet another Philco 48-200 Code 121 and C302, the AVC capacitor, is indeed .05.
That's three Code 121's (plus the OP's) that have .05 for that value, while the schematic which covers the Code 125 shows .1uF there.
For the record, I put a scope on the AVC line with my .047 in place, then put another .047 in parallel (approximating .1uF) and didn't see a difference in voltage or operation of the AVC.
I think if the original Philco cap is in there, you can trust the value if it's .1 or .05, and if someone had already replaced it, chances are it was a .1 in a Code 125, and a .05 in the Code 121.
Somewhere out there, I believe, is a 48-200 with .147 uF for the AVC, and that works also. That's because after recapping and checking the schematic, I came up one .1uF cap short and soldered it in, not realizing that because of where Philco had placed the AVC cap, it wasn't obvious that the .05 I'd replaced was actually in. I'm pretty sure I stuck a .1 in parallel, and then sold the radio. Didn't seem to make a difference, and the buyer never complained.
Sorry about the "necro-post", but I wanted to close out the question about C302 for future Googlers out there. I didn't realize until after posting my question, that I had a junker in the garage of the exact same model and version that was ready to answer my question!
Dan
That's three Code 121's (plus the OP's) that have .05 for that value, while the schematic which covers the Code 125 shows .1uF there.
For the record, I put a scope on the AVC line with my .047 in place, then put another .047 in parallel (approximating .1uF) and didn't see a difference in voltage or operation of the AVC.
I think if the original Philco cap is in there, you can trust the value if it's .1 or .05, and if someone had already replaced it, chances are it was a .1 in a Code 125, and a .05 in the Code 121.
Somewhere out there, I believe, is a 48-200 with .147 uF for the AVC, and that works also. That's because after recapping and checking the schematic, I came up one .1uF cap short and soldered it in, not realizing that because of where Philco had placed the AVC cap, it wasn't obvious that the .05 I'd replaced was actually in. I'm pretty sure I stuck a .1 in parallel, and then sold the radio. Didn't seem to make a difference, and the buyer never complained.
Sorry about the "necro-post", but I wanted to close out the question about C302 for future Googlers out there. I didn't realize until after posting my question, that I had a junker in the garage of the exact same model and version that was ready to answer my question!
Dan
"Why, the tubes alone are worth more than that!" (Heard at every swap meet. Gets me every time!)
Philcos: 90, 70, 71B, 610, 37-61 40-81, 46-420 Code 121 to name a few.
Plus enough Zeniths, Atwater Kents and others to trip over!
