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: 4 Guest(s)
[-]
Recent Posts
B&K 1077B no video
Hello Tim, I would if it's a leaky Capacitor So are all 3 of those B- voltages low then ? Sincerely Richardradiorich — 01:55 AM
B&K 1077B no video
I found a schematic and think I have the problem traced down to the minus power supply. I have very low voltages that go...TV MAN — 12:41 AM
RCA 15X
I'd try replacing the bulb first and if that doesn't do it, then change the 35Z5 and see if the problem goes away.NostalgiaRadioTime — 12:28 AM
B&K 1077B no video
Hello Tim, I have that exact unit in my shop too plus a Sencore unit there are times I like one or other !!. Sincerely...radiorich — 11:07 PM
RCA 15X
Everthing goes at once, maybe it's the cold weather, I have had 2 dial strings break and no my little RCA is having dial...Paul Philco322 — 10:26 PM
Philco 91 Schematic
Hi Dan, I can't explain this specific resistor but I have seen the use of a switch to apply B+ voltage to screen gri...RodB — 09:36 PM
6TPZ and 5TPO Radio Help
I suspect it's been repaired before. And I suspect whoever repaired it, wanted to re-use old transistors' pin stubs in o...morzh — 09:24 PM
B&K 1077B no video
Thanks Rich! I'll take a look and see what he has. I know there's more modern equipment to be had, but this one I know a...TV MAN — 09:11 PM
B&K 1077B no video
Hello Tim, Here is a link to restoration of one on Phil's old radios site ! Sincerely Richard bk1077bradiorich — 09:01 PM
6TPZ and 5TPO Radio Help
I'm a little befuddled on this one. Should X5 and X4 be tied together like this?  It looks like someone added this at so...R3Sons — 07:33 PM

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

>