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

Need help, Philco 37-620, 6A8 cathode circuit
#1

I am restoring a 37-620 Philco and need advice regarding the cathode circuit of the 6A8 tube in the RF chassis. I purchased a set of service bulletins and schematics from Chuck and in reviewing the schematics, the earlier version bulletin #250 shows the cathode of the 6A8 connected to chassis ground. My 37-620 seems to be a second run with some updates but has the cathode grounded. A later service bulletin #251A has a 100 ohm, #21 and a .05 cap, #19 to ground. Should I install the later version or leave the grounded cathode? Many thanks for your help.
#2

Your set may have been "monkeyed" with before you got it.

Go by the schematic that matches the CODE version of your chassis.
Code version will be on the blue and white paper label on the inside of the cabinet or ink-stamped on the chassis rear apron.


Chuck
#3

Thanks for the info Chuck. I looked over the chassis and there is no code number. The only thing that I found was run #2, so I am going to follow your suggestion and use the 37-620 service bulletin 250. Many thanks for your help.
#4

If you do no see a 37-620 Code xxx on the chassis or the blue and white paper tag glued to the inside of the case, then you have a Code 121, Run #2.

Merry Christmas,

Chuck




Users browsing this thread: 1 Guest(s)
[-]
Recent Posts
Need to purchase some accessories for restoration of my Old Philco Radio
Hi Paulo, Welcome to the Philco Phorum. I can see why you want to find good reproduction parts. That is a bea...MrFixr55 — 11:10 PM
HiFi (Chifi) tube amp build - but my own design.
Tim, I have some bakelite sockets in my work shop that I can dig up. I believe quite a few are NOS. I will take photo...RodB — 10:03 PM
Philco 610B oscillator wiring
> The cathode as noted is wired directly to the ground side of the heater filament for that tube, not to the #17 and ...Radioroslyn — 08:12 PM
HiFi (Chifi) tube amp build - but my own design.
Tim; I noticed your post a little late, but I would take one of the junk sockets and try to break a chunk out of it wi...Arran — 08:07 PM
Need to purchase some accessories for restoration of my Old Philco Radio
Here is a list of resources found in our online library that you might find useful. Mike's Gobs of Knobs email addres...klondike98 — 01:46 PM
First Radio restoration
Hi Tubeman, Welcome to the Philco Phorum.  Phamily Phriendly Pfun with Phine Pholks Phull of Philco Phacts. (See a p...MrFixr55 — 12:33 PM
First Radio restoration
You could post in the WANTED ADs section here on the Phorum and see if anyone has an RF generator that they want to sell...klondike98 — 11:55 AM
Zenith H725
Good ideas, thank you Arrange and Rich. I have the adhesive aluminum foil already and can try that immediately. More ...EdHolland — 10:18 AM
Graphics for majestic 1050 dial glass.
Murf; I found this thread on the ARF, the first photo has a pretty good view of the dial glass. Regards ArranArran — 01:12 AM
Zenith H725
hello Ed, how about that speacial tape used for ducting it's like foil or how about thin piece of aluminum roof flash...radiorich — 12:19 AM

[-]
Who's Online
There are currently 1940 online users. [Complete List]
» 4 Member(s) | 1936 Guest(s)
AvatarAvatarAvatarAvatar

>