[PAradiogeek]

Hi Everybody,

I picked up this radio a year ago off the 'bay and I've finally decided it is time to attempt a restoration. Here are three pictures:

https://www.flickr.com/photos/104710683@...551856068/

The first shows the cabinet. Overall it is in fair shape. The finish is pretty bad, but the frame and the veneer seem to be in good shape so I think it can turn out good.

My question tonight has to do with the chassis (pictures 2-3), which as you can see is in pretty bad shape. There is a lot of rust, but underneath it is actually pretty clean. I need to remove the RF sub-chassis, and before that, I need to remove the dial assembly.

Photo #2 shows the chassis front and the dial face. I don't see how to remove the dial face. There is a round 'nut' with two holes (pointed to by the arrows in the photo). Do I use these holes to loosen the nut and remove the dial face? Does this require a special tool?

In looking at it closer, it almost appears that the whole dial assembly might be able to be removed by loosening two screws shown in photo #3 (arrows). These screws are behind the dial assembly, but seem to attach it to the front of the tuning cap assembly. Will the whole assembly come off if I remove these two screws?

If not, what is the best way to remove this stuff?

These are probably basic questions, but I don't really have a mechanical aptitude, and in spite of its rough condition, I don't want to ruin this radio.

Thanks in advance.

[VntgRads]

Just came across this doing my "searches" just in case you have any interest. I have no personal attachment to this listing.

http://www.ebay.com/itm/antique-philco-3...2592c5533e

Craig R.

[Radioroslyn]

Hi Jon
To remove the dial insert the tips of a pair of needle nose pliers into those two small round holes and give it a twist to the left. It will release the dial.
GL
Terry

[PAradiogeek]

Craig,
Thanks for pointing me to the other chassis. It seems to be in better condition than mine. I may try to get it.

Hi Terry,
Thanks for the explanation. I'll give it a try this evening.

Jon

[PAradiogeek]

I've been making progress on my 37-630 this week. I removed the dial (thanks Terry) and then the entire RF sub-chasssis. I restuffed the electrolytic and replaced all of the paper caps and one out of spec resistor. Even though I removed both of the side walls of the sub-chassis, one of those paper caps was a bear to replace. Finally got it though

I took a wire brush attachmenent to my Dremel tool to get at the worst of the rust on the top of the RF chassis. I'll go after what is left with naval jelly soon.

Last night I managed to check continuity on all of the antenna/RF/oscillator coils. No opens;) I applied some Deoxit to the band switch contacts as best I could and worked the switch for 10 minutes or so. Other than the previously mentioned rust removal and later some paint, I think I'm pretty much done with the RF chassis at this point. Wasn't as bad as I had thought it would be.

[mikethedruid]

You have a great radio there. I'm glad to hear you are making good progress. I had a similar model from when I was about 13 into high school, when I traded it for another console. Back almost fifty years ago, all I had to do was replace the filter condensers, and a tube. Once you get them working well they are very good receivers. Keep us posted about your experience. I also look forward to seeing the work on the cabinet. I've done a few, so feel free to ask questions. Don't lose heart or patience, in the end you are going to have a GREAT radio there that will be playing still for another 3 generations. Best of luck !

[PAradiogeek]

Mike,

Thanks for the encouragement. This is my first console restore, so it will definitely be a challenge for me. I'll take you up on your offer if I get stuck somewhere.

Jon

[morzh]

Consoles and cathedrals are really no different when it comes to electronics, and I do not see differences in restoration technique or effort intensity. Let alone the fact that some early 30s consoles, tombstones and cathedras shared the same chassis.
They just look intimidating, being so big.

[Warren]

Just alot more work if your refinishing the cabinet of a console as compared to a shelf type radio.

[Phlogiston]

Yep. And they sell for less too. But not because they are less cool, or sound worse. They are a lot more work and take up floor space. I think that I have somewhere in the range of 35 consoles (6 in the house) and would have more if I had room to stack them - hum, there is an idea - -

   

P.S. Don't be lookin' at those empty shelves! I assure you that they are full now.

[PAradiogeek]

One of the things I will need to do soon is to replace the candohm. The schematic shows that this resistor includes 202 ohm, 8 ohm, and 35 ohm resistence elements. Unfortunately, none of the documentation indicates a power rating for these resistors. I did some calculations, but the physical sizes are huge and will make it difficult to fit my replacement into the available space. If someone is willing to double check my work, including my assumptions, I would really appreciate it. So here goes.

Riders schematic says that total power is 65W.
The heater current power consumption is as follows
Tube. Current. Voltage. Power
6K7. .3A. 6.3v. 1.89W
6K7. .3A. 6.3v. 1.89W
6F6. .7A. 6.3v. 4.41W
6A8. .3A. 6.3v. 1.89W
6Q7G. .3A. 6.3v. 1.89W
5Y4G. 2.0A. 5.0v. 10.0W
Total -->. 21.97W. Round to 22W

Thus the total power minus what is used by the heaters is: 65 - 22 = 43W. This is the power consumed by the circuitry connected to the high voltage winding.

The highest voltage I see is 250V at the plate of the 6F6. Using I =P/V the high voltage current should then be 43/250= .172A.

I believe that essentially all of this current flows through the candohm, so using
P = I*I*R, I get the following power numbers :
Resistor. Power. Resistor rating needed
202 ohm. 5.97W. 20W
8 ohm. 0.23W. 2W
35 ohm. 1W. 5W

Sorry for the long post, but do these numbers make sense?

Thanks in advance,
Jon

[PAradiogeek]

There ought to be a law against being this dumb

Over the last several days, I finished recapping and recarboning this set. Last night I put the rf chassis back in and wired it up. I decided to go over my notes one more time to check that everything had been replaced. It was then that I noticed that I had never checked the tubes. Doh!!!

I did that and found that two tubes were bad. And of course, for one of those, I did not have a spare. I had been hoping to power her up last night, but now I have to order a few tubes and await their arrival.

It's a good thing radio restoration isn't a race, becuase if it was, I'd definitely lose.

[Tom Hamilton]

Good luck with your 37-630. I've got a table version of the 37-630. I've got a few other things ahead of it that I need to do, but one day...

Tom

[PAradiogeek]

OK, I finally got my tubes yesterday. I had done a dim bulb test over the last couple of days, with no tubes, and then with the rectifier tube only. All of that went well, so last night I installed the tubes and powered it up...

Nothing.

I poked around for a half hour or so. B+ seemed fine. Got noise/hum if I touched the 2nd detector grid, but nothing but silence on all three bands.

Then I realized that I didn't have the shadow meter plugged in. I retrieved it from the cabinet and plugged it in. Radio played!!!

So now I'm looking at the schematic and trying to figure out exactly what a shadow meter is. The schematic doesn't seem to be on NA or I would provide a link, but the symbol for the shadow meter doesn't really tell me anything about what it is (like a coil?).

So can anyone enlighten me on this? I've run other radios without their eye tubes installed and they worked.

Thanks,
Jon

[Mondial]

The shadow meter is actually a DC milliameter. It is connected in series with the plate B+ supply to the AVC controlled RF and converter tubes. If the meter is unplugged, these tubes will not receive plate voltage.

The meter indicates tuning and signal strength because the plate current of these tubes is dependent on how much AVC voltage is generated. On a weak or no signal, there is no negative AVC bias and the tubes operate at full plate current, which makes the shadow meter deflect and cast a wide shadow. With a strong signal, there is a high negative AVC voltage applied to the RF and converter tubes, which reduces their gain and plate current to a low level. Therefore the meter deflects very little and the shadow is narrow.

So the shadow meter really displays tuning by the inverse relationship of the plate current of the tubes controlled by AVC and the level of the received signal.