not sure without looking at the schematic, it prob just protects the flyback but that is a guess. I would fuse it right off the rectifier with a fuse rated a bit above the max B+. I assume it uses tube type rectifier, so the B+ current should be slow to come up, which is good for both the caps and a fuse. I have to admit I would prob not bother with the fuse unless I had a good reason to pull it apart again. Since you clearly stay on top of it, you would prob turn off at the 1st sign of distress caused by a bad cap (sudden shrinking of the pic for example). Clearly you should not leave it unattended for any length of time.

Hard to beat those old Admirals! Excellent picture.

I have had good luck getting electrolytics of several brands to reform and hold voltage by bringing up the voltage slowly enough. By slowly enough I mean over 3 hours or more. I connect a voltmeter across the main filter cap and adjust the variac for something like 10 volts on the cap. Then every 5 minutes I increase the voltage by 5 volts across the cap.

The potential problem is that the oxide layer in an old cap may un-form more quickly than a new one would if you do not use the set regularly. If you turn it on once a month you probably will have no problems. If you turn it on once a year, you are more likely to have problems.

Another problem with old caps is that they can dry out and stop acting like a capacitor. This is not dangerous as this will not cause overheating, but the set may not work correctly.

By playing the TV say, an hour or so a day, would that reform the electyrolytics? How long would that proceedure take?

I fixed the Andrea, BTW. Loose 5U4 Socket was cutting out the HV.

If they are running cool at full voltage then they have already reformed. Some do not deteriorate much with age and some reform quickly. The procedure I described often allows you to fix up caps that would overheat and blow off the electrolyte if you just applied full voltage suddenly.

The fuse inside the HV cage is very likely a 1/4 Amp just for the flyback. It's worth checking that fuse as I found 10 Amp fuse stuck in one of my sets
Some runs had two fuses side-by-side. The other being a 2-3 Amp for the AC line.

Well, given how extraordinary the picture is emitting from this TV, I had to see what was up with the CRT. I dug out the B&K 467 and hooked it up again.

The emissions now reads into the Green, at 1.2. It seems to be waking up on it's own! The Set Cut-off, Tracking Test, and Life Test all read well.

Back From The Dead...

First, the .25A fuse is to protect the flyback in case of a short.

If you guys seriously think you can use old electrolytics indefinately, let me clue you in.
When they dry out, and, short, the electolyte actually bleeds out of the layers, and, creates corosion, causing a short circuit path. The corosion slowly eats away at the insulation.
When you reform the cap, it temporarily works again. However, the corosion doesn't go away. It stays. It causes a leakage. The capacitor will still work for a time, but, the leakage puts extra strain on the power supply.
Eventually, due to the continued coroding of the paper insulation, the paper breaks down, and, you have a permanent short. I've heard them go with a BANG!
Then, you are in real trouble if you don't cut power FAST!!

On one Admiral I have the power transformer was dammaged beyond use. I found the culprit. My ohm meter found the first secion of the filter feeding the audio amplifier shorted to 1 ohm.
I fooled with it for the heck of it, and, it temporarily burned the short enough to go up to ten volts, then, you could hear a slight popping in the can as it was breaking down again.
I replaced all filters, and, yes, the dammaged power transformer.

On another, an RCA Victor 9T246, I slowly reformed the filters. It played perfectly for almost two weeks, using it every day.
Last time, as set was almost ready to play, I heard a pop, and, raster came on, no reception.
Leaving it on, I suddenly got smoke. A half watt resistor between sections on one can was burning.
Individually, the filters were charging, but, it was discovered that two sections were trying to charge.
Problem was a short happenned between 3 sections, causing a major overload.
Leaving old filters in to use is only inviting trouble to happen.
I guarantee it eventually will.
Each time that set surges, even on a variac, a little more of the insulation burns away.
For those with money to buy the fancy equipment, an ISO meter confirms the truth to this.

It was also found for the same reason that new old stock reformed filters do the same thing....
INsulation just plain breaks down eventually. Some faster than others.

I'd rather replace the electrolytics than to have to replace expensive power supply parts.
Bill Cahill

I use a fuse in the B+ line, would prevent problems even if a new cap failed or some other issue cropped up. I don't like to trust the breakers that are often used in later sets. On sets that have tube rectifiers you can use a fast blow that is just a bit higher than the max measured current flow. On SS rectifiers a slowblow would be better to get past the initial inrush current. I have thought about adding a thermistor to the B+ line ahead of the fuse on SS equipped sets and then going fast blow for quicker action in case of a short.

Point is there are other things that can go wrong besides filter/doubler caps so the B+ fuse covers most of them. I once had a set that had a shorted disk cap (a decoupling cap from the screen grid of a tube on a color set), it was bad enough to kick the breaker on the set. If the breaker had not been there I am sure there would have been some serious damage, I am just glad it worked, but a fuse would have been safer.