[MrFixr55]

Hi Morzh,

The same technique was used in the Westinghouse designed Radiola 16, 17, 18, 33, etc., and, I guess, carried over to the (RCA) Victor- built Radiola 80, R7, R73, etc. I am sure that it was done as a manufacturing "efficiency". They likely either just had to hammer it down on the unassembled speaker, prior to adding the cone. They may have actually had a press that did it in one step.

One has to remember that some RCA radios introduced during the "Roaring 20s, particularly the Super VII, at $425.00, more than a very well-appointed Ford Model T! The coffin cabinet Radiola 60, in 1928 in the middle of the roaring 20s went for $140 without speaker. The Radiola 80, introduced during the Great Depression, much more radio than the Radiola 60, with console cabinet, electrodynamic speaker, push pull output, newly developed screen grid tubes, etc., went for $142.50 The R7A introduced in the throes of the great Depression, with on less tube than the Radiola 80, a table cabinet, but still with a similar speaker to the R80 and with Pentode 47 output tubes in push pull went for $72.50. I assume that the R73 was a similar price saving over the Radiola 60 or 80. This could only be done with economy of scale and more efficient methods of manufacture. Of course, the Depression caused manufacturers to tighten their belts drastically!

[morzh]

Yes, I am sure this would not be performed with the speaker fully assembled. Can't see how.
I am sure it was like you suggested: a coneless basket, then press the transformer, then put the cone in.
But they coulda saved some extra dough on a thinner gauge steel used for the transformer bracket. Why they needed this thickness - beats me.

[MrFixr55]

Hi Morzh,

I hear you re the metal thickness. On the 16, 17, 18 they put the detector and amp interstage transformers in a metal box that was at least 12 gauge, potted them in some sort of waxy material and installed it in the chassis by bending over tabs. I would think that the box and chassis was at least 14 gauge steel. Dunno if they figured that it would keep from rattling where a lighter gauge would not. Come to think of it, the later speakers like in my GE S-22(RCA R-7A) had a rather flimsy speaker frame, not really like the basket used in the earlier speakers.

In the mid 30s, RCA (and Non-RCA GE) sets, and even Zenith mounted power transformers in some sets by bending over tabs. Designs were constantly changed and improved to speed the manufacturing process. From multi-cap cans, molded plastic cabinets, printed circuits, multifunction tubes like the 55/75/6Q7, 19, 6N7, etc., Transistors, ICs, surface mounted devices, etc. Electronics is one field where manufacturing processes constantly improved efficiency and the benefits were passed down to the Customer.

Nowadays, screws are disappearing from cars, replaced by pop rivets, studs and press on clips, push pins, spot welds, etc. Whatever it takes to streamline the manufacturing process. In some (rare) cases, they actually added parts to do so.

I had to remove the entire dash from my 03 Taurus to replace the AC Evaporator (the entire heater plenum had to be removed). The job was made much easier than on previous cars by the construction of the dash, locating pins, and 2 very large harness connectors.

[morzh]

Oh yeah... the cap can in the radio is also over a 1mm thick....whatever. Cannot be easily unbent. And, without full removing of the coil, impossible. It is also a chiesel/hammer work, same as the transformer in the speaker.

[morzh]

So I thought, lemme check what shape are the filtering caps are.

After I reassembled my speaker with 125C transformer and hooked it up, I populated the tubes and saw the rectifier outputting about 180V which quickly disappeared once the power was off (good sign).

So then I waited for the radio to warm up, and a pretty nasty hum came out, but then I realized it reacted to the volume and tone ctl pots, so I rotated the dial and got my local station about where it should be on the dial (goes towards the antenna coil rewind). So, now I know that radio

1) works
2) needs those caps in the can changed.

I decided, given the thickness of the tabs and the effor it will take to unbend, remove trhe can and then empty it and so on, to simply keep cutting the wires one by one, trace them and replace the caps outside the can. It goes against my own rules, but then the effort should be commensurate with the desire to keep that particular radio authentic, and, well, this is not one of my bucket list ones, plus some caps could not be restuffed anyway due to the way they were, so I allowed unadultarated yellow axials to live under the chassis, no cosplay.

So both good and...neutral news. I did not expect the old cap[s to be ideal, it was just when I measured the capacitance it was right on the money with the 10uF filter cap and so I thought, what if....well, OK, the "if" did not materialize.

[morzh]

Tracing the wires and soldering in the caps was not much fun, the wires being discolored and routed at the bottom of the chassis, plus tied up with a cable twine, so pulling the wire was not really possible....at least the first one.

But....I defeated itm and today put the last four caps into it.
It is not really beautiful, as I had to put 5 or 6 caps on the same solder lug on the resistor board, as this is the only solder post connected to the common negative after the filter choke (field coil). And the caps are aluminum cans and yellow tubulars. Even if good brands. But it works. Taking off and opening that can was a bit too much involved, and I felt reluctant to disassemble the whole chassis RF part to gain access to the tabs, which require huge leverage to be unbent.

Then I simply plugged it in and joyfully heard nothing....that is, no hum; however moving the volum pot wiper produced a bit of rustling sound, so I tuned the dial and heard the locla station, clear, no hum. Touched the antenna, the station became loud. I say, it is good.

Now, I have to make the dial move - no friction between the shaft (smooth metal) and the twine. I might put some rosin on it, or change it altogether.
Then the tune-up.
Not sure it is coming today, but maybe next weekend....

PS> Rosin helped. Found where I stashed it and rubbed it against the cord. Seems to work. Also wiping the shaft with isopropyl dry alcohol first improved things a bit too.

[MrFixr55]

Congrats Morzh, on getting it to work!!  I remember thinking of buying a Crosley Playboy or a Philco 90, but I figured that this (my GE S-22 version of the RCA R7A was rather the same thing.

[morzh]

Surprisingly, the S-22 was there nearby the RCA R-7, at the end of the Kutztown. No one wanted them. I ended up with the R-7.

I do not know if it will sound well with that large inductance missing, but I am sure at a moderate volume it should. That inductance was there to compensate for the shortcomings of the 2nd Detector driver driving the interstage. What I heard sounded OK, and this was without the cabinet. Then again, I do not expect this to be something stellar. It fell in my lap (ouch!) and looked good enough to keep, soo I will be satisfied if it simply works well enough.

I will save my resolve for the RCA140.

[RadioSvit]

I will save my resolve for the RCA140.

I was waiting for it ...    Appetite comes while eating. 

[morzh]

Well, unlike this one, the 140 was one of my bucket list radios, so I was actively looking for it. This would explain my desire and the level of effort expended.

[morzh]

   
   

Well, this completes it.

Today I assembled the radio, after having wiped some real black, real greasy stuff with mineral spirits off the inside of the chassis bottom cover, that alcohol would not remove. Considering the percentage of the open magnetics, I wonder......well, I best not think of that.

It sounds OK. Do I think the 3H 18K turns burnt inductor in the driver stage, replaced by a few hunder mH one and 3K resistor, is part of it? Maybe. It does not sound amazing, but sounds quite acceptable. Plenty of power, volume; this is the 1st radio that, after the alignment, put the local station at the exactly where it should be, 1160 kC. Not even a shred of the small division to the left or the right.

I have a small video, but I stopped posting on youtube a few years ago, and i am not sure where to put those anymore without being sniffed by those bots. Like in "The Matrix". So the photos should suffice for now.

3 months it took me. Willy-nilly. Not bad.

[Joe Rossi]

Michael, This is a very beautiful radio! I have enjoyed your restoration narrative. Joe

[morzh]

Joe,

Thanks.

[Ron Ramirez]

I agree with Joe. It looks great. Good job.

[morzh]

Thanks Ron!

Actually, I was surprised that the grill cloth was intact and clean! The radio clearly was put away due to insurmountable repair problems (2 chokes and the output transformer open), and obviously was kept somewhere where it was dry and fairly clean.
There was a repair attempt, I guess, as the screws,m that held the rails to the back of the cabinet, were gone. But I think, it progressed to the realization of it being too much, and I saw no signs of soldering or replaced parts.

So having a fairly clean cabinet and good cloth (and!!! surviving the trip in Kirk's van! Which is in itself a very dangerous thing for a radio to undertake!) is surprising.

PS. Thanks Kirk!