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

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

Philco 42-380 conflicting wiring vs schematic
#1
Photo 

Thanks for having me in the forum.  I collect radios and have restored several Philcos over the years.

I inherited a Philco 42-380 from my Dad.  It had never worked while he had it.  I know it is a pretty common one.  I am in the process of restoring it and am awaiting some parts at the present. 

While in the process of replacing  the original rotten rubber wiring I noticed that pin 5 (plate) of the 6X5 rectifier is tied to the ground connections of the two 71 audio output tubes.   There are no ground connections currently on pins 5 and 6 of the 71s which is in direct conflict with the schematic.  I know there is a history of 6X5 rectifiers destroying the main transformer.  I plan to replace it with two diodes to prevent that but wonder why the factory would have done this?  I assume it had to run with this configuration since there is no sign of it being done by a previous service.  The audio output transformer and speaker field coil were destroyed long ago by capacitor failures.


Attached Files Image(s)
   





Users browsing this thread:
[-]
Recent Posts
Philco 42-345 Restoration/Repair
Yes, 57 is an electrolytic cap that should be 12 mfd 400 volts according to the parts list from the Phorum library schem...RodB — 06:01 PM
Philco 42-345 Restoration/Repair
Looks like if I am reading it correctly it looks like the silver capacitor#57 that appears to be a replacement is of a l...osanders0311 — 05:09 PM
Philco model 38 code 121 not receiving signal.
Thanks Arran. Yeah this plastic is pretty thin. It's a little thinner than the original stuff. It kinda reminds me of p...Stormlord5500 — 04:37 PM
Testing a speaker and output transformer Trutone A2-G
The equivalent of one short turn is basically the same as that of a shorted load. If it is the primary's turn, then the ...morzh — 03:53 PM
Testing a speaker and output transformer Trutone A2-G
I've never had an output transformer become shorted, the failure mode is usually an open primary, or in a center tapped ...Arran — 03:52 PM
Philco model 38 code 121 not receiving signal.
As long as the plastic sheeting isn't too thick, I think that the thickness of photographic film would be just about rig...Arran — 03:19 PM
Philco model 38 code 121 not receiving signal.
Well why not! :lol:Stormlord5500 — 03:14 PM
Philco model 38 code 121 not receiving signal.
Good luck next thing you know you will be winding coils just for the fun of it. DavidDavid — 11:29 AM
Testing a speaker and output transformer Trutone A2-G
morzh Short-circuited turns can be considered as a half-dead transformer. But on this case transformer will hot and s...Vlad95 — 11:01 AM
Testing a speaker and output transformer Trutone A2-G
I am not sure how a transformer could be weak. It could be inadequate, but only when you replace the original with somet...morzh — 09:56 AM

[-]
Who's Online
There are currently no members online.

>