[Oldie Goldie]

On page one of "Part74-Philco Wiring Diagrams Vol. 1.pdf"
I think deleting the 0.01uf branch part of C51 would improve the fidelity of the radio on today's bass HEAVY modern AM band.

One switch position would be light bass boost and the second position would be ZERO bass boost.

Rather than light bass and heavy bass.
Again I think it's lame and stingy that Philco put in a two position switch for a "tone control".
The other manufacturers of the mid to late 30s were smart enough to use a pot and single tone cap. The end user can dial in the tone they want, with Philco you get TWO choices and you better like it"

Philco seems like the equivalent of early 2000s PowerPC era Apple!


Should get rid of the flabby old fart sound signature. And its reversible.

[morzh]

It will pop it out until fully assembled and the Jesus clip is in place. Fully assembled means, the inner shaft is inside, and then the whole thing is inside the bushing that holds the large balls inside.
I wish I documented the 37-604 I just did. Or the 620. But it was kind of self-explanatory to me, so I did not document it.

[Oldie Goldie]

What is this Jesus clip?
I see only one copper spring clip and it has zero to do with the inner shaft flying out when I turn the fine tuning control.

[Oldie Goldie]

It's pretty clear to me and it works perfectly after I assembled it but a few turns of the knob it makes a click noise and the dod jumps out a few millimeters.

Now the only thing I didn't do was use grease, I used a drop of oil after the black crud was cleaned out and scraped away.

I'm at a loss what I'm doing wrong.

[klondike98]

Have you seen the seen the dial rebuilding thread in our library? https://philcoradio.com/library/index.ph...uilding-2/

[Oldie Goldie]

Klondike98, no but it looks like it's the wrong mechanism. But it has lots of interesting data.

[MrFixr55]

Hi Oldie.

The "Jesus" clip is the circlip that holds the outer shaft in. People call them Jesus clips because when they shoot off into a parallel dimension one says "Oh Jesus". I don't like to take God's name in vain, but I am not above using "salty" language, so I call them oh$#!^ clips, because that is what I say when they spring off. Whatever nomenclature that you use, this is the "C" shaped clip that snaps behind the gear on the outer shaft.

The mechanism that Klondike indicates may be different externally from yours, but the innards should be similar. I believe that the inner shaft is held in by the 3 balls. The outer shaft acts as a "race". The balls are sandwiched between the "cup" of the mounting body and the tapered area of the inner "vernier" shaft. If the end of the shaft or the cup of the mounting body is too worn, this may be why the shaft is popping out. Try slightly larger ball bearings. You may have to slightly enlarge the 3 holes in the "coarse tuning " shaft.

[Oldie Goldie]

MrFixr55, ok that's what I thought it was. I hope it wasn't some mystery piece that was inside that was stopping this whole thing in its tracks that I didn't know about.
So I guess I'm not missing any parts.

The reason this thing isn't staying together is because it's worn out.

I even tried shimming it up with something.

I'm still open to the possibility I'm not pushing the inner rod in at the right moment or something weird.

For the time being I put it all together, bagged the ball bearings and spring up. And just slapped the fine control on the outer knob with sticky putty.

[morzh]

Circlip, c-clip, e-clip, snap ring - all types of the retaining ring. Also called "Jesus clip". The reason being, it often flies out during attempts to install it, never to be found, and this is often folowed by "Oh Jesus!" exclamation. Or so the legend goes.

[morzh]

The inner shaft should snap in place.

Mr. Fixr, sorry did not see your post, so omine was redundant.

[morzh]

OK, found it.

Ron's 37-640. The last page

https://philcoradio.com/phorum/archive/i...760-5.html

Is this the gear?


PS. If it keeps doing it, maybe the balls have worn out a groove and so are not compressed much anymore.

[Oldie Goldie]

Ok I took a tea candle and used it's metal cup for thin shim material.
Cut a long straight piece and put it inside the cup that gets bolted to the chassis. There is a deep wear groove in there where the three balls have worn in.

Worked perfectly for a bout a dozen turns. Than the metal disintegrated and was all chewed to bits.

Anyways, tired of spinning my wheels with that stupid tuning assembly, I satisfied myself with doing that fidelity mod to the tone circuit.
Lifted the ground of the twin capacitor (52) and indeed I got two new tone settings,
"No bass boost" and "light bass boost".

With the bass boost turned off, the thing wakes right up with chrisp highs. But if I turn the volume up too high I get a shrill zeeeeee! sound out of the speaker. Satisfied with the nondestructive experiment I resoldered the ground back to factory config.

I don't know what kind of small value cap needs to be in circuit if there is essentially no capacitor in the tone circuit when in no bass boost setting to stop that high pitch howling.

But poking around looking at the plethera of crusty cold solder joints and paper caps alongside new capacitors tacked in circuit with the Philco bake light blocks;
this radio is a game of Jenga.
It plays now but the circuitry is a sickening mix of original paper and Philco block caps, new modern caps of unknown brand slapped in, crusty cold joints, and bodge wires mixed with crumbling rubber wire.....it's waiting for something to fry up.

Oh and I bagged up the balls and spring for later...I don't know. But ironically the shaft won't come out now.

[Oldie Goldie]

morzh, yeah that's basically the same shaft I have.

Your probably right, that the ball bearings have gouged a groove so deep that while under spring tension any slop as it's turning it would come apart. I think the outer bolt on thing is cheap pot metal.

I need a new one. And I wonder if anybody on the forum would mail me one for a few bucks.

Btw, I was never about to get the three bigger balls bearings out, they were just stuck in those little holes.

[Oldie Goldie]

Only thing I can think of is using something tougher for shim material like very thin steel or brass?
Whatever soft garbage metal the tea candle cup was made of just shredded after a dozen turns.
But while it was intact, the whole thing worked great. Positive clues here.

[David]

Using brass go to the range look at different spent shell casing find one the right size then cut to length. David