37-630 Intermittent issue - solved
Posts: 395
Threads: 33
Joined: Jul 2013
City: Horsham, PA
I restored this radio about 2 years ago. Over the past 6 months or so, I started noticing that after the radio was played for more than 30 minutes or so, all sound would sometimes cut out. This didn't happen every time, but seemed to happen more and more as time progressed. When this would happen, I found that giving the cabinet or the chassis a gentle rap would restore the sound. It finally got bad enough that I decided to take a look underneath, assuming I had a bad solder connection somewhere.
Well I took it downstairs a few nights ago and played it (in cabinet) for almost 2 hours - played perfectly
The next night, removed the chassis from the cabinet, turned it upside down and turned it on again. I started probing around with a plastic stick, touching wires and solder joints. - played perfectly . After a couple of hours, I gave up for the evening.
So last night, I decided to give it another try. I turned it on and started probing around again, still no luck.
Then for no particular reason, I decided to take a look at the shadow meter, not because I suspected it was the problem, I just wanted to look at the deflection of the vane. The shadow meter had been connected, but strewn off to the side while I had been probing in the chassis. As soon as I started to move the shadow meter the sound cut out, just like it had been doing over the last several months. I put it back where it had been, sound again
There seems to be an intermittent right were one of the wires from the chassis goes into the coil. I used some glue that I had to try to hold the wire in place, thinking of adding some JB Weld to that to make a more stable fix. Does that sound like a workable solution?
Anyway, I just wanted to post this in case anyone else ever had a similar problem. I knew the shadow meter was required for operation, but I had never suspected it as the source of the intermittent. Moral of the story: Check EVERYTHING!
Happy Holidays!
(This post was last modified: 12-22-2016, 04:21 PM by PAradiogeek.)
Posts: 15,761
Threads: 551
Joined: Oct 2011
City: Jackson, NJ
In many Philcos the Shadowmeter is bypassed with 2-3K resistor, so when the shadowmeter quits the radio still plays.
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.
Posts: 395
Threads: 33
Joined: Jul 2013
City: Horsham, PA
Thanks Morzh,
Can a bypass resistor be added if it wasn't in the original? If so, how do you size it in terms of ohms? The SM in my set measures 1400 ohms on a DVM.
Posts: 7,284
Threads: 268
Joined: Dec 2009
City: Roslyn Pa
(12-22-2016, 04:36 PM)morzh Wrote: In many Philcos the Shadowmeter is bypassed with 2-3K resistor, so when the shadowmeter quits the radio still plays.
Hi Jon,
How tricks up in north Montco???
Took a quick look at the 37-630 schematic but I don't see a resistor across the shadow meter as Mike describes. My older 660 does have one. You could disconnect the sm and use a 1k or 1.5k 1/2w resistor in it's place. If that clears up the problem you'll need to rewind your sm coil. You could also monitor the hv at the bottom of the 1st IF transformer as the sm feeds it. If you see the voltage fluctuating a lot it's time to rewind. I suppose there could be an issue with the sm coil heating slightly from it's normal operation. THis might cause a sm break in the coil where it's warm.
When my pals were reading comic books
I was down in the basement in my dad's
workshop. Perusing his Sam's Photofoacts
Vol 1-50 admiring the old set and trying to
figure out what all those squiggly meant.
Circa 1966
Now I think I've got!
Terry
(This post was last modified: 12-22-2016, 05:14 PM by Radioroslyn.)
Posts: 13,776
Threads: 580
Joined: Sep 2005
City: Ferdinand
State, Province, Country: Indiana
DO NOT use J-B Weld on that shadowmeter. It is conductive.
--
Ron Ramirez
Ferdinand IN
Posts: 7,284
Threads: 268
Joined: Dec 2009
City: Roslyn Pa
(12-22-2016, 05:11 PM)Ron Ramirez Wrote: DO NOT use J-B Weld on that shadowmeter. It is conductive.
Sounds exciting!!!!!!!!!
Maybe you won't really need that resistor!
When my pals were reading comic books
I was down in the basement in my dad's
workshop. Perusing his Sam's Photofoacts
Vol 1-50 admiring the old set and trying to
figure out what all those squiggly meant.
Circa 1966
Now I think I've got!
Terry
Posts: 15,761
Threads: 551
Joined: Oct 2011
City: Jackson, NJ
In the model 660 it is a 2K resistor.
In the 37-116 it is 1K.
The less the resistance for the given meter the narrower the segment will become.
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.
(This post was last modified: 12-22-2016, 05:38 PM by morzh.)
Posts: 395
Threads: 33
Joined: Jul 2013
City: Horsham, PA
Thanks Ron! Glad I asked before just putting it on. Do you know of an appropriate glue that I could use? My first thought was hot glue, but I figured things might get warm if the radio is running for a few hours and I wouldn't want that stuff running down onto the chassis.
Thank you also Terry. Things are going well, trying to get ready for Christmas. We usually play Christmas music on this radio during the day on Christmas, so I wanted to get it ready. Uggghh, I hope I don't have to rewind that coil, but I realize that may be the only permanent solution. How have you been?
Morzh: "Maybe you won't really need that resistor! " Too funny.
Posts: 7,284
Threads: 268
Joined: Dec 2009
City: Roslyn Pa
> How have you been?
So old rotten self!!!
Tnx for asking.
When my pals were reading comic books
I was down in the basement in my dad's
workshop. Perusing his Sam's Photofoacts
Vol 1-50 admiring the old set and trying to
figure out what all those squiggly meant.
Circa 1966
Now I think I've got!
Terry
Posts: 15,761
Threads: 551
Joined: Oct 2011
City: Jackson, NJ
(12-22-2016, 08:26 PM)PAradiogeek Wrote: Thanks Ron! Glad I asked before just putting it on. Do you know of an appropriate glue that I could use? My first thought was hot glue, but I figured things might get warm if the radio is running for a few hours and I wouldn't want that stuff running down onto the chassis.
Thank you also Terry. Things are going well, trying to get ready for Christmas. We usually play Christmas music on this radio during the day on Christmas, so I wanted to get it ready. Uggghh, I hope I don't have to rewind that coil, but I realize that may be the only permanent solution. How have you been?
Morzh: "Maybe you won't really need that resistor! " Too funny.
That's not me, that's Terry.
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.
Posts: 13,776
Threads: 580
Joined: Sep 2005
City: Ferdinand
State, Province, Country: Indiana
(12-22-2016, 08:26 PM)PAradiogeek Wrote: Do you know of an appropriate glue that I could use?
Clear epoxy.
--
Ron Ramirez
Ferdinand IN
Posts: 395
Threads: 33
Joined: Jul 2013
City: Horsham, PA
Thanks Ron,
Ditto Morzh for setting me straight.
Sorry Terry. I somehow misread that and didn't notice it was you.
(This post was last modified: 12-23-2016, 12:49 AM by PAradiogeek.)
Posts: 1,125
Threads: 78
Joined: Jan 2014
City: Annapolis, IL
Gotta love those intermittent problems! These type of problems seem to follow me for some reason. Had a bunch of those when I was in electronics professionally. I had my model 70 fail recently - intermittent also. Will start a new thread on that later when I decide to tackle it. Clear silicone (or any color ) would work to hold your SM wires. Anyway, glad you found it.
If I could find the place called "Somewhere", I could find "Anything"
Tim
Jesus cried out and said, "Whoever believes in me , believes not in me but in him who sent me" John 12:44
Posts: 15,761
Threads: 551
Joined: Oct 2011
City: Jackson, NJ
What worries me about the silicone that is sold in stores, it really reeks of vinegar and from what i read it is for a reason - it does either exude acetic acid when curing or something to that effect.
Acid could damage wires.
Maybe it's an empty scare but I do not like acid smell near copper wiring.
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.
Posts: 1,475
Threads: 69
Joined: Nov 2012
City: Kansas city, MO.
You could maybe use something like this. Little pricey though.
https://www.amazon.com/3M-Scotch-Weld-Ep...B000X5G6O6
Users browsing this thread: 1 Guest(s)
|
Recent Posts
|
Philco 38-2 Low Volume
|
Hi MrFixr55, The aux sound was good and yes it can be made too loud. The tone has no real effect on volume just tone, ge...dconant — 06:04 PM |
RF Choke and Condenser -42-PT-7
|
Hi Folks,
If you are talking about Part #7, this is the cap that capacitively grounds the physical chassis to B- and...MrFixr55 — 06:04 PM |
Photo-finish repair
|
Thanks for the reply Bob. I think I will try the touchup process. Do you have any suggestions on what I should use to ...georgetownjohn — 05:52 PM |
Philco 38-2 Low Volume
|
Hi DConant,
I don't think that the extra 0.7 MOhm would make much difference. If the pot was supposed to be a 500KOhm...MrFixr55 — 05:21 PM |
Photo-finish repair
|
Welcome to the Phorum! :wave:
Once upon a time there was a supplier for some photofinish decals but no longer that I...klondike98 — 05:21 PM |
Philco 38-2 Low Volume
|
Hi MrFixr55, Thank you for the drawing. I can handle that. I disconnected the muting switch from the center pin of the p...dconant — 04:50 PM |
Philco 38-2 Low Volume
|
Sorry, I did not see your post as I was writing mine. I would think that with a consumer electronics level Aux input of...MrFixr55 — 04:24 PM |
Philco 38-2 Low Volume
|
HI DConat,
It wouldn't hurt to put a 0.01 uF cap between the deck and volume control. However, there is a 0.01uF cap b...MrFixr55 — 02:57 PM |
Philco 38-2 Low Volume
|
I connected my tape deck to the pot as stated with a .01 cap between. Volume is still low. Maybe I am expecting too much...dconant — 02:57 PM |
Philco 38-2 Low Volume
|
Well,
your IF is your RF Input signal minus the Local Oscillator.
So, your IF = |RF - LO|
(that is the absolute...morzh — 02:25 PM |
Who's Online
|
There are currently 1875 online users. [Complete List] » 3 Member(s) | 1872 Guest(s)
|
|
|
|