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

Squealing like a pig 53-1750
#1

9/12/20
Hey folks.  I did a total recap on 53-1750 radio/phonograph about 3 years ago.   Has been running like new all this time,  but lately it still works with low volume but  if I turn the volume beyond a low volume,  I get a  LOUD high pitch squeal with no other sound. 

 Doesn't matter if it's the phono or the radio, same squeal.    All tubes test good and replacing them from another working set does not help.  I thought perhaps it was the volume/tone control, but a new one made for me by Mark Oppatt did not solve the problem.  All 5 electrolytic capacitors were removed from the circuit and tested - all are good with both a capacitance meter AND and an ESR meter.  Before I go replacing all the caps again, any suggestions as to what part of the circuit(s) this squeal may be coming from?   If I tap around, it doesn't seem like anything is loose   Thnx
#2

Any shielded tube that should have it's grid cap inside the shield and doesn't?
Or tone control caps....or the cap in parallel to the audio primary?

People who do not drink, do not smoke, do not eat red meat will one day feel really stupid lying there and dying from nothing.
#3

I would check C19, C17, C18 those number are from looking at model 53-1754 could not find info on a model 53-1750. Stay safe David
#4

I do not even see the 53-1750 model in Riders online.

People who do not drink, do not smoke, do not eat red meat will one day feel really stupid lying there and dying from nothing.
#5

You guys are good.  After rechecking connections with a magnifier and bright light, I found this bad connection on this cap where it was soldered on to the buss terminal. I would have never noticed it without the magnifier -  after a re-solder, the set works good as new again.   

Thanks for your help.


Attached Files Image(s)
   




Users browsing this thread:
[-]
Recent Posts
Philco 91 Speaker Replacement
The spider is glued on the cone and so is the voice coil. I think you can use a cotton swab dipped in acetone and carefu...RodB — 02:42 PM
Restoring Philco 37-604C
Yes I saw that. If I knew, I'd probably try to arrange for getting it myself. But I have just got one. Which does not m...morzh — 01:44 PM
Philco 38-2 Automatic Tuning
When you push the lever, you are supposed to rotate the disk to the desired station. Then the magnetic tuning will acqu...morzh — 01:42 PM
Philco 38-2 Automatic Tuning
I figure out the muting from another picture that helped. Now I need to know how the automatic tuning works. When I push...dconant — 12:11 PM
Philco 91 Speaker Replacement
How would I go about removing the spider from the cone?dconant — 12:04 PM
Philco 38-2 Automatic Tuning
Hello, I am having trouble getting my automatic tuning to stay unmuted. If I play with the tuning handle I can get it to...dconant — 10:51 AM
Does anyone make photofinish replacements?
Here’s the link to the DIY photofinish section of our site: klondike98 — 09:46 AM
Delco car radio Peko vibrator converstion issues
Hi Richard, Thx for posting the schematic.  As I remember as a kid, these were great performers for the time, likely...MrFixr55 — 08:56 AM
Delco car radio Peko vibrator converstion issues
hello mr Fixr, The Electro  Powersupply that I am powering the radio with has a huge choke plus a 10,000ufd electrolyti...radiorich — 10:58 PM
Delco car radio Peko vibrator converstion issues
How about putting a choke in the power supply? The big cap was likely an attempt to stabilize the DC. Kids who cre...MrFixr55 — 09:19 PM

[-]
Who's Online
There are currently 2967 online users. [Complete List]
» 2 Member(s) | 2965 Guest(s)
AvatarAvatar

>