Philco 37-10 magnetic tuning problems
Posts: 804
Threads: 42
Joined: Dec 2008
City: Chicago, IL
I recently dug into my first Philco - a 37-10 with automatic / magnetic tuning - and set out to restore it.
[Image: https://farm4.staticflickr.com/3030/2989...64f5_z.jpg]
[Image: https://farm6.staticflickr.com/5679/2375...c9d9_z.jpg]
It worked fairly well well when I got it then sat in a closet for a few years. This was my first good luck under the chassis and I was surprised to see so little work had been done to it. Just a few new electrolytics and paper caps. I later found that the volume and tone controls had been replaced too.
[Image: https://farm6.staticflickr.com/5776/2402...e36f_z.jpg]
[Image: https://farm2.staticflickr.com/1442/2375...9c47_z.jpg]
[Image: https://farm2.staticflickr.com/1503/2405...1b61_z.jpg]
Posts: 804
Threads: 42
Joined: Dec 2008
City: Chicago, IL
Next I recapped it including unmounting the RF unit so I could really get down in there.
[Image: https://farm2.staticflickr.com/1580/2346...8e21_z.jpg]
Replaced all the rubber mounts while I was at it.
[Image: https://farm6.staticflickr.com/5829/2398...05a9_z.jpg]
All the bakelite and electrolytic caps were restuffed.
[Image: https://farm2.staticflickr.com/1673/2359...0d36_z.jpg]
[Image: https://farm2.staticflickr.com/1704/2419...59a8_z.jpg]
I also discovered the 2M volume control had been replaced with a 500K and the tone/power switch replaced with a potentiometer and switch. I got replacements from playthings of the past and restored the original wiring.
[Image: https://farm2.staticflickr.com/1557/2427...55e5_z.jpg]
[Image: https://farm2.staticflickr.com/1619/2430...54c0_z.jpg]
The radio played great on the first power up Plenty of volume and selectivity. However, the "magnetic tuning" feature doesn't seem to be working.
[Image: https://farm2.staticflickr.com/1576/2406...87f8_z.jpg]
Turning it on and off has almost no effect on the tuning. It certainly isn't locking in on a station. I did some voltage checks and found the 6N7 oscillator control tube only has around 180 volts on the plates. The service info states 260. That voltage is derived from the junction of the 10K and 15K in a bleeder network of 10K, 15K and 51K.
(This post was last modified: 01-14-2016, 06:32 PM by Bob Andersen.)
Posts: 804
Threads: 42
Joined: Dec 2008
City: Chicago, IL
Huh, it's working now  I just kept poking around and finally got the discriminator coil to peak 
Here's a look inside the IF / descriminator can for the curious. The variable cap at the top is the one I had trouble peaking. Maybe my opening up the can and blowing the dust off fixed it ?
[Image: https://farm2.staticflickr.com/1620/2401...9a6c_z.jpg]
Posts: 5,129
Threads: 271
Joined: Nov 2012
City: Wilsonville
State, Province, Country: OR
Posts: 2,573
Threads: 337
Joined: Jun 2013
City: lawrenceville nj
Great looking bob 
Great vid too
Sam
Some day, and that day may never come, I will call upon you to do a service for me. But until that day, accept this justice as a gift
mafiamen2
Posts: 804
Threads: 42
Joined: Dec 2008
City: Chicago, IL
Thanks! Next installment uploading right now where I demonstrate the magnetic tuning. It really does work well once properly adjusted.
Posts: 1,475
Threads: 69
Joined: Nov 2012
City: Kansas city, MO.
Very nice job, and thanks for posting the magnetic tuning video.
Posts: 594
Threads: 41
Joined: Aug 2010
City: Shepherdsville, KY
Hi Bob
Really like your YouTube vedios. I just finished a magnetic tuning philco, I had to read the alignment instructions several times before I got it right. Especially tuning the AFC. Keep up the good work.
Joe
Joe Bratcher near Louisville, KY
Posts: 804
Threads: 42
Joined: Dec 2008
City: Chicago, IL
Thanks! Does anyone know where I can get a new dial glass ? I suppose I could pick up a piece of glass any try cutting it myself but the curves look tricky 
[Image: https://farm2.staticflickr.com/1503/2377...696a_z.jpg]
Posts: 594
Threads: 41
Joined: Aug 2010
City: Shepherdsville, KY
Hi Bob
Really like your YouTube vedios. I just finished a magnetic tuning philco, I had to read the alignment instructions several times before I got it right. Especially tuning the AFC. Keep up the good work.
Joe
Joe Bratcher near Louisville, KY
Posts: 2,573
Threads: 337
Joined: Jun 2013
City: lawrenceville nj
hey bob
I think I have a 38-116 glass around here
that should be the same yes??
sam
Some day, and that day may never come, I will call upon you to do a service for me. But until that day, accept this justice as a gift
mafiamen2
Posts: 804
Threads: 42
Joined: Dec 2008
City: Chicago, IL
Hmm. I don't think so. It looks like the side are straight in the 38-116 while angled a bit in the 37-10. http://www.tuberadioland.com/images/phil...16x_13.jpg
Posts: 4,816
Threads: 54
Joined: Sep 2008
City: Sandwick, BC, CA
Bob;
Maybe you could trace out the shape onto cardboard and get a glass shop to cut a new piece? That is unless you know someone who does a lot of stained glass work, they would have the tools to cut and grind glass.
Regards
Arran
Posts: 13,776
Threads: 580
Joined: Sep 2005
City: Ferdinand
State, Province, Country: Indiana
Bob
Have you considered plexiglass? I cut a piece of plexiglass for that type of escutcheon once, several years ago...it wasn't easy, but a heck of a lot easier than cutting real glass...and looked fine once installed in the escutcheon.
Or if you decide to go with real glass, Arran's suggestion to go to a place that does stained glass work sounds like an excellent suggestion.
--
Ron Ramirez
Ferdinand IN
Posts: 804
Threads: 42
Joined: Dec 2008
City: Chicago, IL
Thanks for the tips! I'll see what I can do. Meanwhile, I've been reassembling the automatic tuning mechanism and have a few questions.
1. What type of bulbs should be used ? I found two types installed - #44 and some fat 3W bulbs.
[Image: https://farm2.staticflickr.com/1632/2431...fe1d_z.jpg]
2. There is a chrome reflector ring around behind to station identifier tabs. I'm pretty sure all four bulbs should point towards that reflector but the top two on mine point forward. That only illuminates the inside of the cabinet! Should I bend them so they point into the dial ?
[Image: https://farm2.staticflickr.com/1677/2431...a4e4_z.jpg]
[Image: https://farm2.staticflickr.com/1492/2431...2b67_z.jpg]
3. Finally, I'm confused about the audio muting switch. I understand that it should short out the audio to ground when the tuning handle is pressed in. The inner contact on mine is just sort of floating around inside. I think it should line up with the other contact mounted on the shaft. Not sure if I'm missing something that would secure it in position.
[Image: https://farm2.staticflickr.com/1711/2442...d8c1_z.jpg]
[Image: https://farm2.staticflickr.com/1608/2442...8c2a_z.jpg]
an anyone shed some light on these issue ? Thanks!
(This post was last modified: 01-16-2016, 11:47 PM by Bob Andersen.)
Users browsing this thread: 1 Guest(s)
|
|
Recent Posts
|
|
An attempt to remove the Field Coil from a G speaker
|
| Mike;
I've only run into a speaker with an open filed coil twice, and they were on newer speakers from the 1940s. One ...Arran — 12:48 AM |
|
An attempt to remove the Field Coil from a G speaker
|
| Arran
Yes, this is my plan for now and what do I got to lose, this is not even the speaker from this radio, but one o...morzh — 10:44 PM |
|
An attempt to remove the Field Coil from a G speaker
|
| Mike;
I would unwrap the field coil, and see if maybe there a break near one of the ends, like where the coil wire att...Arran — 10:23 PM |
|
An attempt to remove the Field Coil from a G speaker
|
| ...and this is what I did. I fed a little LT into the screwholes with a small brush, and a little on the rim next to the...morzh — 09:52 PM |
|
Philco 40-120C Restoration
|
| I combined the two 40-120C threads together as we like to keep the discussion of the same radio together. It helps with...klondike98 — 09:36 PM |
|
Philco 40-120C Weak, Distorted Ouput
|
| Just checked were I buy tubes price is four dollars. So living in Florid we have a local source for tubes. David David — 09:14 PM |
|
Philco 40-120C Weak, Distorted Ouput
|
| The higher voltage may be due to higher mains voltage. My mains run 120-125AC when the set was new mains would be 110-11...David — 09:09 PM |
|
Philco 40-120C Weak, Distorted Ouput
|
| Thank you for your reply. I pulled a speaker from a Philco 41-221 and received the same result. I used a signal tracer t...bluecap — 08:45 PM |
|
Philco 40-120C Weak, Distorted Ouput
|
| Have you tried a different speaker?
How did you trace the distortion?
How do you know it is weak? What is the reference?...morzh — 08:33 PM |
|
Philco 46-480 Electronic Restoration
|
| Amen to that! Every time I think I’ve captured them all, I realize that there’s another error. My goal is to finish with...jrblasde — 07:00 PM |
|
Who's Online
|
There are currently 980 online users. [Complete List]
» 1 Member(s) | 979 Guest(s)
|
|
|
|
 
|
![[-]](https://philcoradio.com/phorum/images/bootbb/collapse.png "[-]")
