Welcome Guest! Be sure you know and follow the Phorum Rules before posting. Thank you and Enjoy! (January 12) x

Thread Closed
Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5

Replace IF transformer caps?
#1

Hi all, I'm restoring a Philco 40-155T slant front and it's coming along great. Got her all re-capped and a re-coned speaker is on the way. This radio sounds really nice, really powerful and I have a good cabinet. 
I'm questioning if, since I'm into it now, I should replace the caps in the transformer cans. The radio plays awesome, and it's some trouble to pull the cans, and I always hate doing surgery around coils. But maybe I should just do it rather than wonder later. What d'ya think?
Thanks,
Alan
#2

No, the caps inside caps are usually micas and should be left alone unless explicitly failed.
Goes for all mica caps.

People who do not drink, do not smoke, do not eat red meat will one day feel really stupid lying there and dying from nothing.
#3

Unless they are post war K-tran or Automatic style IF cans, the mini If cans used in millions of AC/DC sets from the late 1940s onward, leave them alone, Philco used either molder micas or ceramic caps in these sets I think, except for a large one used on the pushbutton banks.
The one on the P.B bank does go bad so I would change it, it looks like a sandwich with no case on it. One item to check though is the audio output transformer, the primaries on those often fail in these sets.
Regards
Arran
#4

Thanks guys, just the answers I needed, didn't want to go there. Thought maybe I would be heading off the dreaded silver mica disease.
Alan
#5

Silver mica disease ails a specific type of caps, the open kind, not the overmolded laded type. At least not as badly.

People who do not drink, do not smoke, do not eat red meat will one day feel really stupid lying there and dying from nothing.




Users browsing this thread: 1 Guest(s)
[-]
Recent Posts
Rogers Majestic R-646
Thanks RpdB I don't think there's much difference with interstage transformers of different models other than dimersion...Vlad95 — 03:27 PM
Rogers Majestic R-646
Vlad; I looks like your set has the same problem that mine did, both a bad output transformer, and a bad audio inters...Arran — 03:21 PM
Rogers Majestic R-646
Ouch! Not often the secondary takes a hit. Wish there was a better solution. I have a good interstage transformer but it...RodB — 02:59 PM
Rogers Majestic R-646
By the way, the bypass you suggested is a rare solution in some circuits. For example, this schematics solution is used...Vlad95 — 01:43 PM
Rogers Majestic R-646
No, you are wrong, because you did not know the details. Unfortunately, only ONE winding out of six is intact in both t...Vlad95 — 01:14 PM
Rogers Majestic R-646
The output 45s are still in push-pull because the transformer secondary winding is still in the grid circuit providing o...RodB — 11:52 AM
Rogers Majestic R-646
Thanks RodB for the help. But this is not a real solution to this situation, not even a temporary one. Because the firs...Vlad95 — 11:34 AM
Philco Model 16 wiring question
I was going to check the voltages as you suggested and hooked it up to my dim bulb. It appears I have a short. The bul...bobclausen — 10:34 AM
Rogers Majestic R-646
You can bypass the interstage transformer by disconnecting the primary, connect a load resistor of about 10k - 20k to th...RodB — 09:40 AM
HiFi (Chifi) tube amp build - but my own design.
So, here's Prince on stage halfway through Purple Rain when he stoops down to his tech and says "Rod, pull out that...RodB — 09:17 AM

[-]
Who's Online
There are currently 1032 online users. [Complete List]
» 1 Member(s) | 1031 Guest(s)
Avatar

>