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Restoring Philco 37-604C - Printable Version

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Restoring Philco 37-604C - morzh - 10-08-2024

This radio has been on my list for a long time.
This Kutztown, I got lucky: Joe Koester had it for a very reasonable price, and when I looked at it, he immediately dropped it down to a mere $100. That was the offer I could not refuse.

I have published some photos before; the bezel (escutcheon?) has a little viewing window damage.

   
   
   
   
   

I opened it up. The opening is a learning process.
Then I decided to remove the tuning assembly.
If only for gaining access to the capacitors' can.
Plus the grommet is bad, and one of the two grommets on the two shafts (volume and the switch) is missing.

That comes down to removal of two wires and a Grounding braid.

So, below is the bottom of the chassis

   

Front
   

The chassis on the stand near the Riders (Good thing I have it: the NA somehow does not have the 37-604)
   

And, the last, the assembly removed
   

Now to the recap. First the regular caps, then the can.
Oh...at a minimum, the choke on the left, one of the two filter ones, is open and one wire was cut.
I have my work cut out for me.

RE: Restoring Philco 37-604C - MrFixr55 - 10-09-2024

Interesting set on several levels. Interesting that it uses a bias cell for the 6Q7 grid. Wonder why they did not use the field coil as part of the power supply filter, putting it across the B supply instead? Did they get better flux that way? First time I saw an AC-DC radio use 2 chokes.

Good luck with the restoration, the radio is a looker.

RE: Restoring Philco 37-604C - morzh - 10-09-2024

For starters, batteries do not produce hum....

The battery is still there.

RE: Restoring Philco 37-604C - RodB - 10-10-2024

MrFixr- look at the schematic for the Philco 650 from 1936. Two chokes. Think of the weight and power dissipation. But look, when one burns open, you have a spare, installed.

RE: Restoring Philco 37-604C - morzh - 10-10-2024

Rod


650 only has one filter choke.
The other one is the Field coil.

The 604 (and 37-604, which is more or less the same radio with octal tubes) does have 2 chokes.

RE: Restoring Philco 37-604C - morzh - 10-10-2024

I ordered some 1.5 AAA holders.
Hopefully this will do the trick for the bias cell.

RE: Restoring Philco 37-604C - morzh - 10-10-2024

I am about to order tuner grommets and washers from RR.
There is one more part I need: it is a shaft bushing. Or maybe flanged sleeve bearing.
There are two: one goes over the volume shaft, and the other over band switch shaft.
They are sentering the shafts in the two brackets extending from the tuning assy.
It is a hard plastic, made in a shape of centering tuning support grommet.
RR does not make them.

Any ideas?
It cannot be any rubber: it should not create friction a rubber would against the rotating shaft.

PS. There are some on Amazon; have to look for the right size, if it is in existence there.
https://www.amazon.com/Nemco-NEM55419-55419-Bushing/dp/B01858W6S2/ref=asc_df_B01858W6S2/?tag=hyprod-20&linkCode=df0&hvadid=692875362841&hvpos=&hvnetw=g&hvrand=5663707128875069755&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9003678&hvtargid=pla-2281435177858&psc=1&mcid=4573ed4c0227359c8b47427e438973c6&hvocijid=5663707128875069755-B01858W6S2-&hvexpln=73

RE: Restoring Philco 37-604C - RodB - 10-10-2024

I just googled 1/4 inch flanged bushing and got a bunch. Teflon, nylon, plastic, brass and rubber. Other sizes available. Didn't expect the large variety.

RE: Restoring Philco 37-604C - radiorich - 10-10-2024

morzh,
I am lucky that one my local stores also carry some of diffrent sizes nylon, plastic, brass and rubber.

Sincerely Richard

RE: Restoring Philco 37-604C - morzh - 10-10-2024

The bushing I need is

Bore: 7mm (7.1mm) - 0.28"
OD: 9mm (9.3mm) - 0.36"
Flange 12.7mm

Cannot find on eBay or Amazon.

RE: Restoring Philco 37-604C - Arran - 10-10-2024

Mike;
Those button cells are carbon zinc cells that were produced, and marked by P.R Mallory, and were somewhat of an engineering "FAD" in the mid to late 1930s. Canadian Rogers, and Canadian Marconi built sets used a lot of them, typically two of them, one being on the wiper of the volume control. Personally I think it was a scheme for companies to avoid paying patent royalties, likely to RCA, though that would not have mattered in Canada as all companies belonged to a patent pool. Anyhow there are some modern watch or coin cells that are a viable substitute, except that you have to reverse the polarity of the holders because on the watch cells the exterior is positive and the center is negative, Apparently you can revive the originals by dropping the cell into boiling water, though I have not tried this.
Regards
Arran

RE: Restoring Philco 37-604C - morzh - 10-11-2024

Well, button cells like LR41/LR44 of 1.5V would do. But there are no holders for them. The holders I see hold minimum 2 cells. I only need one.
So I decided to go with a AAA one.

RE: Restoring Philco 37-604C - radiorich - 10-11-2024

Hello morzh,
Here is a sight that has a lot great stuff Keystone Electronics I buy from them all the time .


https://www.keyelco.com/index.cfm



Sincerely Richard

RE: Restoring Philco 37-604C - morzh - 10-11-2024

Rich

Thanks.

I bought the clip from Amazon yesterday.

I saw this site yesterday; I hold Amazon prime, and so my shipping is free, so if I buy something for $1, it will be $1, whereas in other places I would have to pay shipping.
I do if I have to....like yesterday with Renovated Radios.


Keystone is, of course, good reputable source, which is the only one I use in my designs at work (usually bought from Mouser for the prototypes and then our CM will by elsewhere from their sources). Amazon, unfortunately, sells off-brands, but a $1 plastic AAA holder is most times OK to buy from anyone, though I saw one I decided not to buy on Amazon - I did not like the way the negative spring looked.


My question is, why no one seems to sell a single-cell holder of small button cells like LR41? I literally left no stone unturned. Minimum it was 2-cell.

Frustrations, frustrations.

RE: Restoring Philco 37-604C - morzh - 10-11-2024

Here's my thought:

My requirements for the bushing are:

Bore: 7mm (7.1mm) - 0.28"
OD: 9mm (9.3mm) - 0.36"



Amazon has this

https://www.amazon.com/Qimoo-Flanged-Bearings-Wrapped-Bushings/dp/B0CW33558R/ref=sr_1_2?dib=eyJ2IjoiMSJ9.oSjVQZeXRvkneQ_0U8mYS6IyL0hMyxe9kkIcQ-eR6mKU7e0xHXAh45VWXHQk0X4Nrfcpv4oo4B1MfEsY95jJqlF1-FkQ2m3NiLIcgaXx7jwe5_au47krpk9jLmEZJfBzkzQ8Tclg2v_SDO6HHYbr_n99IVT6MrPBIswfMjbbrEt08-_rLuNjYUAhrlJ3FHDgBYjfqkIAdYhA02EV82VlCuHJT452OqX_7vaQoQsG9X0qm1eEcuccg8-RCwzNARSphiAsAFQluOGO1nHFqO_WM5KF0fdVqHPsskVJ8cKq7IU.Fayd1Rq3dsaiPJyJ2IFcqHIvwi4LhMU2TSjviLVdTWQ&dib_tag=se&keywords=Flanged%2BSleeve%2BBearings%2Bnylon&qid=1728670870&s=industrial&sr=1-2&th=1

M8 Bore, 10.6mm OD

Or this

https://www.amazon.com/HARFINGTON-Flanged-Bearings-Plastic-Bushings/dp/B0D11VTB2L/ref=sr_1_3?dib=eyJ2IjoiMSJ9.WH6UN162O8Mcuv4BK3bs8SFOaVM-i9M0S2EKsJmj9-f9M9mPLSxJjD9Dy1UV9wmFMcBQIFraREdRes4LKH6PoY33LKdFeGU8cEXi15HSDADdjUM_qdLw3wOkyUebX_nAcHp2ZVNvj4KjlCGauEUKwNCqIa_aKfsulRMYGYCq9auQLeLfLp21Ty3boInECd8KFduRzm2TIey4_AFPHPgvW2nYmXqVubFulAjryiOPTnClojcO8Rt909e7IFXboEdCzL3H-WQ3ggvFLHEatfyMZKrPlKsoLzFdxsr5Yt81kQA.8NnCzlcl0zhu1QZVB7XCXtiHmFsBnDydX2Ki_jzsgSE&dib_tag=se&keywords=Flanged%2BSleeve%2BBearings%2Bnylon%2B8mm%2Bbore&qid=1728671193&s=industrial&sr=1-3&th=1

8mm Bore, 10mm OD

What if I buy this, cut some 2-3mm slit and make a split bushing out of it, that just might fit.
I am not, after all, using it as a bearing, it is a sleeve for the shaft.

What do you guys think?