GE LC-628

[electra225]

There are circumstances when using a power transformer power supply that increasing line voltage would indicate the need for increased working voltage filter capacitors. Transformerless, half-wave supplies won't develop sufficient voltage to overload a cap that is the factory recommended value. 160 WVDC caps have a certain tolerance, say, 20% that will raise the safe working voltage to almost 200 volts surge voltage in any case. A transformless supply without a voltage doubler of some kind can't develop near enough voltage to overload a 160 WVDC filter cap if everything is in good shape otherwise. I bought a large quantity of 250 volt caps a couple years ago that I use in AC-DC sets. I don't need anything that large, but they aren't good for transformer sets and they were cheap.....

[TC Chris]

I ordered up the caps a couple days ago and expect them here momentarily. But then last night I fired up the VTVM and used its more accurate ohmmeter to check resistors. Three of the old dog bones had drifted up. My stash of resistors had nothing in those values of course, although I could get close to one of them by using 2 in series. They're mostly high range ones 2 meg and 5 meg. My theory is that resistors that have drifted may affect performance but they won't burn up parts like bad caps might, so when the new caps arrive I'll fire it up and see how it performs, then install new resistors at leisure.

Also did some more joint-and-ply gluing. Getting there, step by step.

Chris Campbell

[electra225]

Those high-resistance dogbones may be in the AVC circuit. They won't blow anything up, but the radio might not work very good if they have drifted. It took 80 years for your radio to get old, you can expect it will take some time to make it work like it's young again. Sounds like you are on the road to success. Good luck!

[TC Chris]

One of them looks like an AVC component. But if it has drifted high, that would just make the AVC action less effective, right? Less effect on the gain? More reaching for the vol. control?

Chris Campbell

[TC Chris]

A miraclel!!!! I just added the new filter caps to the little set, plugged the tubes in and fired it up. It's receiving local stations just fine, which is expected daytime service here. Tonight I'll see how well it does at an hour when AM booms in. But that's not the miracle.

The miracle is that I plugged in the tonearm, put a needle in the cartridge, ran my finger across it, and the cartridge is working.!!!! All those exclamation points is because this device sat in a storage unit for about 40 years now, subject to a wide range of temps and humidities, things that are supposed to kill crystal cartridges. Before that it lived in a basement subject to occasional flooding, causing elevated humidity. And yet it seems to be working.

The dial cord does slip a bit. I did not have a diagram for restringing, so I put 4 turns on the tuning knob shaft. Seems to me that usually 3 is prescribed, and I figured one extra might give me more grip. Nope. Somebody mentioned a friction-increasing workaround a while back. What was it?

And finally, the vol. control pot is noisy. No surprise there. I'll add a bit of cleaner tonight.

Chris Campbell

[TC Chris]

Tonight I tried again. Local stations loud; distant ones weak in volume but there. I'll bet it's the upward-drifted resistors. Cleaned the vol. control and tried to get the tuning string to stop slopping when going backward.

Who are we recommending now for resistor orders?

Chris Campbell

[TC Chris]

Making progress of the incremental kind. I stripped and stained (x2) the "plinth" board. The set has black-painted bands at the top and bottom and a skinny one at the "plinth"edge, and I painted those black. The fake burl band had flaked a bit (masking tape yanked some off) so I hit the bare spots with stain, which hides them pretty well. My new grommets for the motor mount arrived today and look like they will work, with some height added.

After work I painted the black bands again. Later I'll go out and hit the plinth board with shellac wash, and try out the grommets. Eventually I'll hit the whole case with a coat or 2 of varnish. The varnish will go right over the black paint, which was flat black and needs some gloss anyway to match the original. Still waiting for my new resistors to arrive.

Chris Campbell

[electra225]

Sal has resistor kits, so does Just Radios. I usually go to AES. They are high, but they are also local and I can get what I need without having to store extras.

[TC Chris]

The new grommets fit, but lacked height. I have a perpetual supply of old bike inner tubes so I cut a few shims to add height. The new grommets are harder or stiffer than the old ones but this is not exactly a hi-fi device so I'm sure it won't matter.

Chris Campbell

[TC Chris]

While Greg has been wrangling Tolex, I've been laying on varnish. First I mixed up some stain varnish and clear varnish and laid a few coats on the turntable board. It was a nondescript veneer that had been under toned lacquer. It needed color and some opacity. After that I applied the first coat of thinned clear varnish over the old finish on the rest of the case. So far it looks like it cleaned things up nicely. I'll probably do one more coat, wait a good long while, then rub it down some with fine steel wool and wax. We'll see.

Meanwhile the tonearm was secured to its pivot by some sort of clamping mechanism. Maybe it had rubber in the sandwich at some point, but if so, it as long gone. The arm rocked sideways. There were holes, matching holes, in the two parts that joined, so I made up a couple little rivets and peened them over, securing things firmly. I squirted some WD-40 through the horizontal-plane bearings that seemed a bit stiff, figuring that would maybe dissolve some old grease. The vertical-plane pivots were spring-action and created more friction than needed, so I squeezed the spring arms together a bit and solved that problem. This is an old 78 rpm player, remember, so all of this is mostly a theoretical improvement, not something that will affect sound or function much, but doing it right is always a good practice.

As soon as the finishing is done can put it all back together and declare victory, except that I need my new resistors to get things right. This is likely to see most service as a radio, so that should be functioning.

Chris Campbell

[William]

I sound like you are making great progress, Chris. Be sure to share photos when done.

Bill

[electra225]

We will owe each other pictures, Chris. Good luck with your project. Sounds like you are making good progress. Seeing this old stuff come to life again is still a thrill after all these years.

[TC Chris]

I went out and shot some video tonight. When it's done and playing I'll shoot some more and post it. I'm not satisfied with the way the varnish on the motor board leveled (or rather, didn't) so that will need some sanding & recoating.

Chris Campbell

[TC Chris]

Went out to the shop and made a Masonite back for the device. Unlike Greg's back project, mine wasn't because I didn't like the original, but rather because it wasn't there. And since there's 120 VAC on exposed terminals at the back of the chassis for the phono motor, I decided to make one up. Then I took some flat brown paint, added a bit of red to warm it up closer to the original color, and painted the back edges of the box and the new back I had made. Getting closer....

Then I popped the winter commuter bike up on my fancy homemade bike stand, this winter's big improvement to the quality of life, and oiled the chain. The chain takes a real beating in the winter--moisture and salt on exposed steel. The life-quality improvement is that now I can do it standing up and not kneeling on the cold or wet concrete and bending over farther to see where the oil is going. The chain is getting oiled about every week now. Before starting, I measured it to see if it had worn, and it still showed "new" status.

Chris Campbell

[TC Chris]

Let's try some photos of my record player, which I reassembled tonight (except for the chassis, since I'm waiting for resistors). The flash on the camera is a bit unkind to the finish--it's imperfect, but looks better in person.

The attachment P2050546.JPG is no longer available

I made a back for it and added brown paint that approximated what had been there--again, looks better in person.

[TC Chris]

Let's try some photos of my record player, which I reassembled tonight (except for the chassis, since I'm waiting for resistors). The flash on the camera is a bit unkind to the finish--it's imperfect, but looks better in person.

The attachment P2050547.JPG is no longer available

The attachment P2050546.JPG is no longer available

I made a back for it and added brown paint that approximated what had been there--again, looks better in person.



When the resistors are in and it's working I'll finish my short YouTube video.

Chris Campbell

[TC Chris]

Trying again. Can't get the photos to attach properly tonight. Here are the ones I intended.

[William]

It's looking good, Chris.

Bill

[TC Chris]

Woo-hoo.... it's reassembled, and it works! When I first turned it on, it was humming at me and I thought, Oh crap. But the volume pot is still a bit scratchy and I wiggled it a bit and the radio was playing happily (with lots of fluorescent buzz from the shop lights). With them off, the radio performance was much better than expected. I expect even better when the resistors arrive. And the record player works, with its crystal cartridge that's > 60 years old! So I finished my YouTube video. It's in "standard definition," which is lousy. Ill have to figure out how to post in a higher definition. But if you want to see and hear it, here's the link.

https://www.youtube.com/watch?v=Qb48WobryxQ

Chris Campbell

[William]

Great job, Chris, I'm amazed at all the stations you can get. I'm also amazed that you still have all of your childhood records.

Bill