53-1750 Problems when warmed up - Printable Version
+- The PHILCO Phorum (https://philcoradio.com/phorum)
+-- Forum: Philco Radio Discussions (https://philcoradio.com/phorum/forumdisplay.php?fid=5)
+--- Forum: Philco Electronic Restoration (https://philcoradio.com/phorum/forumdisplay.php?fid=8)
+--- Thread: 53-1750 Problems when warmed up (/showthread.php?tid=20560)
+- The PHILCO Phorum (https://philcoradio.com/phorum)
+-- Forum: Philco Radio Discussions (https://philcoradio.com/phorum/forumdisplay.php?fid=5)
+--- Forum: Philco Electronic Restoration (https://philcoradio.com/phorum/forumdisplay.php?fid=8)
+--- Thread: 53-1750 Problems when warmed up (/showthread.php?tid=20560)
Pages:
1
2
53-1750 Problems when warmed up - ODPILOT - 10-23-2019
I restored my 53-1750 2 years ago. All new caps, new tubes, radio alignment, phono overhaul, etc. Has been working GREAT ! Recently, when turned on, it works great but after it warms up, perhaps after about 5 minutes, all of a sudden, it develops loud static and radio reception disappears. This loud static happens on the AM radio band and also the "Special services" band. In phonograph mode, there is no static and the phonograph still plays great. Haven't started messing with it yet but what would be some top choices as to where to start to look for the cause ? Thanks[attachment=20493]
RE: 53-1750 Problems when warmed up - Ed Locker - 10-23-2019
IF transformers (SMD)
RE: 53-1750 Problems when warmed up - radiodale - 10-23-2019
+1 on Silver Mica Disease
RE: 53-1750 Problems when warmed up - ODPILOT - 10-23-2019
If is was the IF transformer, would it not be defective even when cold on startup ?
RE: 53-1750 Problems when warmed up - radiodale - 10-23-2019
Put a scope on one of the grids and look for the popping.
RE: 53-1750 Problems when warmed up - Radioroslyn - 10-23-2019
Two other ways to have a look at it are look closely at the clear plastic bottoms of the two transformers. W/the set and the light off you may see some flashing (arcing) inside the transformer. Another is to disconnect the B+ from the IF transformer's primary and listen to hear if the noise is gone.
GL
RE: 53-1750 Problems when warmed up - gregb - 10-23-2019
Could be silver mica but maybe the oscillator tube is weak, easy to try a new tube if you have one that is.
Gregb
RE: 53-1750 Problems when warmed up - PhilcoFordTesla - 10-23-2019
Beautiful set, I've got one like it I bought off ebay over 15 years ago but it wasn't packed well and pretty sure it was shipped by w'UPS and all it's legs got busted off :-/.
It's standing again with a few pins and elmer's, but it's a worn brown lacquer whatever original finish and 'not nearly as good looking as this luscious blonde,' is she all original finish or repainted? Also lost a knob or two
RE: 53-1750 Problems when warmed up - Jake Blake - 10-23-2019
Let's see that record player.
RE: 53-1750 Problems when warmed up - ODPILOT - 10-26-2019
If it were the oscillator tube, that would still allow the phonograph to play well and would only affect the radio?? thanks
RE: 53-1750 Problems when warmed up - ODPILOT - 10-26-2019
I like this model. My parents had this exact model with the Blonde color when I grew up on Brooklyn. They bought it new in 1953. I bought this one in South Florida, the finish was worn and had some water damage. There is an old wasp nest in the phonograph area. Someone had wired the power for the phonograph motor directly into the A/C cord. The whole thing was a mess. I cleaned up the radio, rewired the phonograph properly, replaced all the CAPS, new tubes, and completely sanded down the finish. There is no current blonde colored wood stain that would match the original on this model. So I went to a local paint sore, purchased a blonde stain and some other color stains and experimented with mixing different proportions and finally came up with the EXACT combination of stains that would produce the original blonde color on this Philco 53-1750. I stained it, then put on a clear coat of lacquer. Looks like new. I retrofit a modern new needle in the phonograph - which has awesome, quiet sound except for the scratches in my father's old records. Cheers.
RE: 53-1750 Problems when warmed up - gregb - 10-26-2019
Yes, the oscillator tube will only affect the radio.
Gregb
RE: 53-1750 Problems when warmed up - ODPILOT - 10-26-2019
Here's the phono. I completely overhauled it. Removed the motor, took it apart and put new grease on the bearings, adjusted it so it "rejects" properly, new rubber belt, rebuilt rubber turret to drive the platter, removed 70 year old dried grease and relubed all moving parts, reflocked the platter with forest green material. Quite a lot of work and to hear my father's actual records playing on this thing from the 1940's, unbelievable.
Best regards,[attachment=20518][attachment=20519]
RE: 53-1750 Problems when warmed up - Jake Blake - 10-26-2019
Veeeeery cool bud!, . . Thanks for sharing.
That must be one of the earliest 45 rpm changers! Looks like it's engineered real well....that control looks like it's cast. Nice.
RE: 53-1750 Problems when warmed up - ODPILOT - 10-31-2019
So folks, I checked all the tubes including the Oscillator tube and they all tested good. I even changed them all from another radio and the static problem on the broadcast bands remained unchanged. When I tap the radio chassis with my finger, I get a "popping static sound" in the radio. So what does that mean, I have loose connection or poor solder connection somewhere or does that still point towards mica disease?