On the bench: Sylvania Halolight 21C611M
 

Allrighty, getting into some meat and potatoes here :D

The attached pics show the restoration process so far, set belongs to a guy in Maryland. This thing had a filter cap bigger than anything I'd ever seen before, it was the size of half a stick of dynamite :eek: !

Decided that the best way to replace the two monster caps was to mount a PC board underneath with stand offs and hot glue. Worked out very well, as you can see :) . I absolutely HATE to leave filter caps dangling underneath a chassis. To me, it's both sloppy and unsafe. Of course, there are times when that's all you can do, but there was enough room to mount everything there, so why not do it right :)

Here's where I'm at right now, and a couple questions. I should preface this by saying that this set is in Sams 389-4 (which I don't have). I realize that some of this could be answered if I HAD the Sams, but I'll give it a shot anyway, just in case someone knows, or happens to have it.

1. In the second picture at the bottom right, note that white thing has been subjected to a tremendous amount of heat.....so much so that it burned off the contact on the junction strip. I assume that's a ceramic resistor of some sort. What is it, and what kind of failure could have caused that much heat?!?!?

2. Same picture, far upper right, there is a dangling wire lead that goes nowhere.....

3. I'm going to need help with this one identifying what I need to do to replace the selenium rectifiers. First time I've done this.....

Hi Tim, I will check this evening, I should have Sams 389-4. Last weekend, my wife and I picked up a really nice looking 1953 Sylvie Halolight, it's the "Montclair" real nice Mahogany finished cabinet, and it sorta works, but CRT very weak, and I have to re-cap as well! My set has twin 5U4' s in sockets, right on top of the power transformer! I will let you know about the 389-4. Dave, Bigdavestv.

Those sets were really overbuilt Sylvanias. Good value for the money.
Then they came out with those sets, like Tim is working on. A chassis like that was found in a $150.00 portable in a $500.00, Halo-light console.
Grossly overpriced. The people that owned them, really thought, they had something, because it was featured at the Brussels World Fair. :thumbsdn:

Actually, you should fix it, with the selenium's in place. Turn it on, measure the current used by the set as it goes through the rectifiers, and measure the voltage drop across the rectifiers, and get your resistor using ohm's law (whoever that was) and then when you replace them with the diode/resistor pair, you can match the exact voltage drop across the rectifier with the new thingie. Instead of guessing, or going by what someone else says worked on his set, which is a different one than yours.... Just my thinkin' You can even put a cap across it if'n you want some AC leakage...

At this point, fixing it with the seleniums in place is a matter of replacing the picture tube and bolting the sucker together.....beyond the two aforementioned questions I had.

Not a half bad idea.

Actually that won't work using a DC or regular AC meter since the
diodes are only on for a small part of the time. Of course you could
theoretically do it with a scope using a 1 ohm resistor in series with the diodes
to measure the current, and calculating using only the peak current and voltage.

But its easier to start with somebody's recommendation and
start the set on a Variac and change the resistor until it gets the
right B+ at 115Vac.

Ah, nice, neat modification. :yes: I assume that new caps had to be connected together to duplicate the values of what might also be described as being the size of 10-gauge shotgun shells. Those are the biggest I'm aware of. I would be learning this stuff easily enough myself, but I still need diagnostic tools. To paraphrase the old Queen Elizabeth High School motto, I (originally "We") learn to do by doing. Anyway, I once read about an old computer once that had capacitors described as being the size of Australian beer cans.

The solder you use, would that be leaded? I read here recently that the lead-free stuff isn't very good.

Oh, of course it's lead solder. And I lick my fingers too! ;) :D

That one cap is about 3/4 size of a small can of Red Bull. I've never seen one that large. Ever.

When it comes to something like this, I don't bother trying to diagnose bad capacitors. If I'm gonna restore a set to be used on a regular basis, I just replace them all.

That's good for the immune system. ;) Agreed about replacing all caps on regular-use sets.

Good job, so far,I agree what you wanted to do won't work right.
Bill Cahill

Didn't notice this at first. Looks like a ballast resistor, and I don't think there was any failure involved, just poor heat dissipation in a high-hour set. A rectangular one tethered to the chassis with some thermal compound in between would probably turn the trick.

Unrelated question:
Is that a Clegg FM-28 in the background?

Sure is! I run that on a homebuilt 2 meter wire hanger antenna that I made that is in the attic. Works very well, actually :)

Thanks to BigDavesTV for the schematic!!!

This is the value that I've got on the selenium rectifiers. From this, can someone help me to figure out what I need to replace it with?

With the seleniums still in place but everything else redone, here's where I'm at....

Have to trace down a dead audio issue and align the picture, but she's looking pretty darn good! :thmbsp: