Mighty Monarch of The Air

[vts1134]

I set to task today and replaced the multi-stage can capacitors with new individual axial lead capacitors.

Cans I replaced.


It was a bugger trying to find room for all of the new leads, but I got all of them in without any shorts.

After picture with the 7 new individual caps.


I have not yet plugged it in because I do not have a variac here at the moment. I don't know if that makes a difference now that I have replaced the capacitors but I wanted to ask all of you. Should I wait until I have a variac to fire it up, or should I fire her up all at once? I await the councils decision.

On a related note does any one have advice on procuring a variac? Specs, things to look for, price range, etc...?

[VintagePC]

Originally Posted by vts1134

On a related note does any one have advice on procuring a variac? Specs, things to look for, price range, etc...?

They can be quite expensive depending on the amperage etc. If you anticipate doing more work on tube sets in the future, it's certainly a worthwhile investment, but for a single set, the cost:gain ratio isn't that pleasing.

You can do without one, a lot of people use what's called the "dim bulb" (no sense repeating what's in a lot of other threads/sites - a quick search will net you the details) method to protect their sets when they fire them up; it gives a nice visual indication very quickly if there is a short, and is essentially a lightbulb-based voltage divider/current limiter.

Or, you can try borrowing one... there are plenty in many university physics labs and if you're friendly with the staff they might let you borrow one for a bit. I borrowed mine when I did my Fleetwood set.

Edit: Note that I meant you can use other protections instead of a variac, not that you can just fire it up without any safety!!

[vts1134]

"If you anticipate doing more work on tube sets in the future, it's certainly a worthwhile investment"

Hehe, I think that ship is sailed. I'm in pretty deep already. I have a set in my basement ready for round two, and I'm constantly on the lookout for rounds 3-26.

[VintagePC]

Originally Posted by vts1134

"If you anticipate doing more work on tube sets in the future, it's certainly a worthwhile investment"

Hehe, I think that ship is sailed. I'm in pretty deep already. I have a set in my basement ready for round two, and I'm constantly on the lookout for rounds 3-26.

That is pretty much a moot point indeed for anyone who has the space/skills. Once you do one, you have an itch to do more. Everyone here's been bitten, I think. However, I do imagine there must be people that do "Just One™" because it was their grandfathers or whatever and has particularly special value to them, but they have no interest in other sets.

(sadly, I have neither a lot of space, nor does anything overly interesting ever pop up in my area. I only got my fleetwood because the previous owners left it in the hayloft of our barn.) Sure, there's the odd AA5 that some idiot wants $200 for, but given my limited space (look at my nickname and if you need a better hint, my website, then take a guess with what it's filled...) and already having a tube radio, I _really_ want to do a tube-based TV set.

[wa2ise]

It helps avoid shorts if you place stripped off wire insulation on the bare cap leads. "Spaghetti" they call it. You can make your own from scrap wire of large enough gauge (old house wire or power cord) or even use coffee stirrers (very small straws).
The "dim bulb"
For a quick substitute for a variac, wire up two outlets in series. One outlet plug in a lamp that has say a 100W light bulb, and the other plug is for the TV under repair.

[vts1134]

No gratification tonight it is. I'll bring a variac home tomorrow, and look to purchase one soon. I had thought about using shrink tubing on the leads on the caps, thanks for the tip wa2ise. I hear you on the no space VintagePC, I live in a sub 900sq foot one room loft with my wife. She has been really suportive of my new obsession, there is no hiding anything when you have no walls.

[Phil Nelson]

I don't think it's a big priority to rush out and spend a bunch on a variac for your first restoration project. If your main concern is not frying your TV, a cheap dim bulb tester actually provides more protection. If your TV has a dead short, the bulb simply lights up, and no harm is done. With an un-metered variac, you can still burn up a power transformer while gradually increasing the voltage, a fact that I learned to my dismay some years ago. A metered variac lets you monitor current use while you increase voltage, of course.

Phil Nelson

[VintagePC]

Originally Posted by vts1134

No gratification tonight it is. I'll bring a variac home tomorrow, and look to purchase one soon. I had thought about using shrink tubing on the leads on the caps, thanks for the tip wa2ise. I hear you on the no space VintagePC, I live in a sub 900sq foot one room loft with my wife. She has been really suportive of my new obsession, there is no hiding anything when you have no walls.

Why not make a wall of vintage TVs? Two birds with one stone