[MrFixr55]

Hi Folks, 

I am beginning restoration on the wonderful Philco 37-116.  My understanding is that this set is the second most Deluxe set made by Philco in 1937.  Mike (Morzh had offered this set and a 38-116 up for adoption.  I took this one.

Here is a pic of the front of the cabinet after a little polishing with Endust furniture polish.  The cabinet is very nice with great wood patterns.  only a little touchup of the front and sides are needed. (I have to wait for Ms. Fixr to leave the house for a few hours till I can get this from garage to office).

[Image: https://philcoradio.com/phorum/attachment.php?aid=35157]

Here's the back.  The chassis in this cabinet is complete, including all tubes, bottom cover but minus mounting hardware.  (The set uses the rather rare 6A4 triode output tubes for 15W output). 
   

Mike gave me a second chassis which was configured for the even more rare 6A5 triode outputs with separate cathode and heater.  Per The 1937 Changes bulletin in our library, this change was made in Code 126.  I thought that per the SN, this is the older chassis, but apparently no.  I guess that I have to find 4 30 Ohm resistors or wire for 6L6s.  I think that by tying Pins 3 and 4, and grounding pin 8, I could choose between 6A4, 6A5 and 6L6 as triodes.  Bias may be an issue.  This chassis lacks the hum balance controls used for the 6A4 tubes used in the other chassis.  I hope to fully restore at least one chassis and repair the other as a spare.  Unfortunately, fore some reason, my little cheapie Motorola phone takes 10MB pix for the chassis and the limit is 5MB.  I don't have any presence on photobucket, dropbox, etc.

I cleaned the spare chassis with 91% Isopropanol, hosed it off with water (sealed off transformer openings first), dried with compressed air and left to bake in the 96Degree sunlight here on Long Island.  I don't have to be that drastic with the "good chassis.  Pic here:
   


Next, I need to check transformers, coils, speaker, etc. for continuity, proper resistance values.  Hope to start recapping the good chassis and cleaning up the wiring soon.

[jrblasde]

That’s a beautiful radio, sir! I’ve had an eye out for one of those. I’m torn, because I hear that the base model (i.e., the regular continuous tuning dial model) was much more rare; then again, I’ve never had one with the automated tuning like yours.

I think it’s so neat that many of you live closely enough to make trades. It’s the Wild West of radios out here!

[morzh]

Joseph,

It is good to have a rarer radio, but to me the DeLuxe version is just that much more good-looking and, well, convenient to use.
And, the magnetic tuning, strictly speaking, while probably has some use in the regular version, was the most useful in the DeLuxe version, as it was correcting the inaccuracy of the preset position of the tuning cap. Whereas when you tune by hand, this is unnecessary, even if if you listen for a long time, it will keep tracking the station in case of the drift.

[jrblasde]

That’s a surprisingly clever solution to the drift issue! It’s too bad the post-war sets with push-button presets didn’t carry on with the same magnetic tuning technology. But I suppose I’ll admit that I haven’t noticed any drift while listening to AM stations on my ‘40s radios; I only experience it while listening to FM, and the push-buttons are only for AM.

[morzh]

That's the thing, there wasn't too much of the drift. But the circuitry is there. And it is utilized better in the DeLuxe because of that low drift. The real usefulness is when using the teledial. Even though the technology went into use in 1936, a year before the teledial was introduced.

The push-button preset, on the other hand, did not really need the AFC any more than a radio without it, as the pushbutton in Philcos did not move the tuning cap, but simply switched on the tuned circuit. Which is stable. This is why you do not see it there.

[Arran]

There were a few Canadian sets that had AFC as well, a number of the high end Marconi sets did, as did some of the higher end Northern Electric sets. The 37 and 38-3116 sets were largely the same as the U.S models. in terms of big sets I would not turn down a 37-3116 if one came along, but I really like the big RCA and CGE sets from this era, the ones with the motor drive, and a curved dial made of glass slats, I don't know if any of those had AFC or not, but likely, I will have to look at the schematic. As Mike said, one they came out with electrical tuned push buttons they did not really need it anymore for AM sets, the pre war sets with AFC usually used a Foster Sealey discriminator circuit of some kind.
Regards
Arran

[radiorich]

Hello mr Fixxr,
What a great-looking radio, and that setup should sound incredible with that amplifier and set of speakers. My General Electric Model L-916 uses two 6V6s in a push-pull arrangement and delivers amazing sound.

Sincerely Richard

[MrFixr55]

OK, started some work, cleaning the chassis that I am going to use.  I did not use the water treatment on this one, but I did hit it with the compressor and air gun.  Cleaned the dust and nicotine from the tubes.  The most important thing is that the OPT, Speaker Field, Power Trans and Audio Driver trans appear to ohm out good, and the speaker cone appears to be good.  Interesting combination of tubes.  One was a 6K7 with the bold letter RCA Logo that replaced the Meatball logo in 1969 or so.  Several other metal tubes were found.  Philco never used metal tubes; thay were an RCA - GE Patent and Philco tubes were manufactured by Sylvania.

None of this would be a deal killer; I would work my way around the issues.

[dconant]

Hi MrFix, I have a 37-116 all restored and working nicely. Fortunately wify does not mind me having radios in the house. I have eight of them in the living area. I enjoyed working on that radio and I am sure you will on yours. The magnetic tuning works as it should. I took the center section out so I could have easy access to the difficult caps. Really no big deal as long as you label every wire. I find taking pictures really does not me help as much as drawing where parts go. I have a 38-116 in the works and very rusty. Where will I put that. Currently the cabinet is out in the workshop waiting for grille cloth, decals and final finish coat. After that move the cabinet into the house for the winter while working on the chassis. I hate being inside while it is warm out.

Enjoy,
Dan

[jrblasde]

The temptation is building to find a 37-116! I happen to favor consoles already, but folks who have a 37-116 always seem to have a particular admiration of it. 

I’d probably want to be more scrutinous of the condition of the cabinet on one of these, compared to my usual purchases!   These ‘30s models have a lot more ornate veneer work, and I could never do it justice if I had to repair a lot of it.

[MrFixr55]

Started to get deeper into the radio.  Fortunately, the audio input and output transformers ohm OK.  I have made a new harness using 20 gauge Teflon covered wire, rated 600V in a nylon sheath.  Not exactly accurate but looks period. (Like my Grumman Aerospace Engineer Dad used to say, "It will look just fine at 10,000 feet."

Both chassis suffered from mice living on top of them, with different sections of each chassis having different areas rusty from mouse urine (hence the heavy use of alcohol during cleaning.  I will try naval jelly first.  Worst case scenario would be to swap sections.  On the chassis that I am restoring, the RF and Audio driver sections are worst.  The IF and Power / Audio Output are better.  I may end up swapping the RF section and leaving the driver section, as the driver has the original, correct and functional driver transformer.  The RF section of the other chassis is very clean (from the water, alcohol and blow-gun treatment.

The biggest problem is not mice getting to the underside, it was previous repairs.  The repairs may have been relatively recent, as plastic electrical tape was used and a relatively recent Pyramid can electrolytic was installed using 60 and 50uF caps across the two 8uF caps (which are already parallelled by Philco), putting about 110uF at the cathode of the 5U4.  Another reason for not powering up the radio prior to inspection and recapping!  I have had to do some sleeving and wire replacement; the original cloth wire is very brittle.

So far, I have replaced most of the electrolytics.  I replaced the two 8uF caps in parallel with a 20uF 500V Nichicon.  Unfortunately, the other 8uF caps come from the Middle Kingdom.  For the last can, there are 8uF, 2uF and 3uF sections.  I intend to replace the 2uF and 3uF caps with Poly/Film 630V caps.  Then onto the blocks, and finally the individual paper-foil caps.  These seem extremely dried out on this set.

I am trying to figure out how I can convert the pix from my $150 Motorola phone that seems to take very nice 10 MB pix and cut them down to the 5MB limit.

Today, I hope to start on some of the blocks.  With the electrolytics done, I am tempted to hook it up and fire it up to see what I have so far.  Film at 11.

[462ron]

MrFixr, when I went many years ago to pick up my 37-116, I had no option of whether or not to plug it in and test it. As I got out of my suv I could hear the hum loud and clear coming from the radio as the guy had it turned on and sitting on his deck. I cringed when hearing that but luckily nothing burned out. It’s amazing that nothing happened because under the chassis there were signs that someone was rewiring things because wires were hanging along with some electrolytics had leads just wrapped around other components and not even soldered, just swinging in the breeze! It’s been probably over 10 years since I restored the chassis but recently the magnetic tuning (afc) developed a problem where when turned on it detunes the oscillator quite a bit but when off it plays normally. Since I don’t really need it I just leave it off. If I ever need to pull the chassis in the future for any serious fault I will delve into the afc problem at that time. I only refinished the cabinet 2 years ago and have it playing in our living room. Looking forward to your restoration progress.

Ron

[dconant]

Oh wow Ron. That guy must have thought that hum was music to his ears. Some people just don't know any better.

Dan

[462ron]

For sure Dan, but what concerned me even more was when I pulled the chassis and saw the hack job underneath and wondered how no damage was done!

Ron

[MrFixr55]

Fortunately, not a lot of mouse damage, but there definitely was human damage to my 37-116.  Note the addition of the electrolytic and the bridging of the other cap.  This has now been cut out.  I may eventually get around to stuff the caps but for now, the replacements are on the underside but have been separated from the originals.  

   

A new C- Bus has now been established with 18 gauge solid wire for connection to the caps and other required connections.  It is interesting that even on the 37-116, Pins 1 and 8 of the output tubes are at B- (chassis ground), as if they intended the possibility of using 6L6s, either glass or metal.  However, apparently both the interstage and output transformers are different between 6L6 and the 6B4 / 6A5 tubes.  For the 6L6s on the 38-116, the secondaries are separate because they add negative feedback from the interstage secondaries to the 6L6 grids.

I started cleaning the IF cans and trimmers which were very dirty, and cleaning the IF and Power / Output chassis sections.  I will likely swap the RF / Osc / Mixer section while recapping it.

I have gotten busy on other projects (need to do front end and gas tank work on the Taurus, have doc appointment, colonoscopy, friend birthday, our anniversary, etc., but hope withinn the next 2 sessions with this set to power up for the first time.