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

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
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
Zenith H725
Ed; One material that I have seen, but never tried for this was material for making exhaust gaskets, it's similar to ...Arran — 11:42 PM
Zenith H725
I just remembered, I have some hi temp silicone rubber material which could do the trick. Or a piece of FR4 laminate. Th...EdHolland — 08:39 PM
Zenith H725
The PSU filter cap arrived today (thank you USPS!) so I will work on that later. Meanwhile, I have the dial, speaker...EdHolland — 06:42 PM
Philco 610B oscillator wiring
Thanks Terry. After checking my notes I think I recorded about -10v at the 6A7 G4/control grid. The screen grid (G3 &...Tubester — 05:59 PM
The list of my radio & TV collection!
Magical chords of forgotten melodies, old nostalgic music on an old radio... Saturday night blues on the Mid-Waves on an...RadioSvit — 12:20 PM

[-]
Who's Online
There are currently 2383 online users. [Complete List]
» 3 Member(s) | 2380 Guest(s)
AvatarAvatarAvatar

>