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

37-620 BC Reception Issue
#1

I have revived this 37-620 radio which was a basket case. This is my first radio. I receive BC signals but they are tough to lock, and I receive loud squelching just before I get the signal. Once I get the signal and get beyond the loud squelching, I have to turn down the volume or else it becomes saturated.

I have a single ended antenna connected to Input 1 with 2 connected to ground, it's length is apprx. 12 feet. It is supposed to be some sort of dual antenna with the center tap of the RF transformer grounded.(Input 3)

My thought is that the alignment might be the cause of this issue.

Any thoughts?

Thanks
#2

A leaking capacitor may cause it to loose a station after it is "locked in"
#3

It locks in, but will saturate if volume is turned up. Also is very sensitive to adjustments. Before station is obtained squelching is heard that you would normally would not get.

I'm thinking something may be slightly out in the oscillator circuit or the tuning capacitor. Not sure what symptoms would be seen with dirty tuning capacitor, I don't believe what I'm experiencing falls into that category.

Thanks
#4

Has it been aligned?
#5

Are all the tube shields in place? If not, you can easily get IF feedback which would cause this problem.
#6

Hi
Like Brenda said missing tube shields especially the first AF or the IF tubes. Also the cap in the agc curcuit or the cap in the IF tube screen grid bypass also the second filter cap or any of the other filter caps. In other words change out all caps. There are several caps that can cause your problem. Icon_biggrin My two cents
Joe

Joe Bratcher near Louisville, KY
#7

Brenda,

That's a good idea on the shields. I will try to find some for this model. Another question on this model is the antenna setup, is it better to try a loop antenna like the one Philco suggests, or just use a single ended one?

Thanks
#8

Single ended random wires work well with these sets.




Users browsing this thread: 1 Guest(s)
[-]
Recent Posts
Jackson 715 not working
Mrfixr55, its working now. I cleaned the switches and sockets with spray cleaner. Thanks for helping on this one.daveone23 — 06:26 PM
Jackson 715 not working
Now that you posted the schematic, I don't know why that Sprague electrolytic cap is across the meter, as it is not indi...MrFixr55 — 05:51 PM
HiFi (Chifi) tube amp build - but my own design.
What may be lacking in the PP Tube amps may be the 2nd harmonics, which some, especially RCA back in the day called &quo...MrFixr55 — 05:32 PM
Jackson 715 not working
Usually in an emission tester, the tube under test is measured as if it were a diode. So, some testers connect all the g...RodB — 04:17 PM
Restoring Philco 37-604C
Yep. F5 is green, D5 is Red. Red is Bad. Green is Clean.morzh — 01:30 PM
Jackson 715 not working
I did start to do that but I stalled out because I could not figure out how the grid and plate get voltage. In this diag...daveone23 — 11:52 AM
Restoring Philco 37-604C
(Insert Homer Simpson "DOPF" Here.) When all fails, look at the can. Took the Ron Ramirez advice, red Caig D...MrFixr55 — 09:23 AM
Philco 91 Speaker Replacement
From your text I am not sure if you intend to use the existing speaker with a resistor instead of the field coil. It wo...morzh — 08:44 AM
Philco 91 Speaker Replacement
My field coil is bad. I am still hoping to find an original, but if I can't I will go with a fitting Philco speaker, 125...dconant — 08:34 AM
Philco 91 Speaker Replacement
As Rod said, it is OK to use a fitting speaker, and then look for an original one. If you buy a Hammond 125 output tr...morzh — 08:15 AM

[-]
Who's Online
There are currently 4012 online users. [Complete List]
» 1 Member(s) | 4011 Guest(s)
Avatar

>