Hallicrafters T-506 scored

[bandersen]

There's an Airline up on you know where that looks almost identical. I guess Airline rebranded the Hallicrafters.

[Phil Nelson]

The Dachis Hallicrafters book says that Sears and Monkey Wards rebranded this set. Delco rings a faint bell, too.

Phil

[bandersen]

I decided to take a whack at this set while I wait for an order of radio parts to arrive. Thanks to Phil's site, I have a good idea what's involved.


Plenty of nasty old caps to replace.




I decided to try something new and restuff the paper caps. They come apart much easier than I expected - just a few seconds under a heat gun.
Then, I wrapped the new caps in some paper to make a tight fit.
Next, a little hot glue to hold them together. Finally, I reused the old wax plugs to reseal the end.


Not too bad, but it's not much fun either. Now, I'll need to really keep track of which caps have been replaced!


Just one problem so far - it's the HV caps.

First, I have a 0.03 and a 0.005 here while the schematic calls for two 0.05 ?!? They look like the originals though (two in the upper-left) Can anyone confirm these values ?


Second, I have a couple 0.00047 (AKA 470pF) for the horizontal. Can I use 0.001 instead ? That's the smallest ASC HV cap I've been able to find.

[jeyurkon]

Nice job of restuffing! The wax they used to seal the ends seems to have a much higher melting point than the wax they dipped them in.

John

[bandersen]

Thanks. Right, the sealing wax meted off right away and the end plugs were more or less intact. I crushed those end caps up and remelted the dust into the ends. I think it will be a lot easier to leaved them as intact as possible and just reflow the plugs over the new caps.

[ChrisW6ATV]

Nice job on the caps. Decades from now, someone is going to own your set and say "How could those old wax caps still be good? They test like new!"

[bkharris]

Looking at the schematic for your Hallicrafters 506 6au6 type late chassis those two vert sweep coupling caps should be .03 at 6000v
However I am not certain that the late chassis schematic is the exact chassis you have.

[jr_tech]

Originally Posted by ChrisW6ATV

Nice job on the caps. Decades from now, someone is going to own your set and say "How could those old wax caps still be good? They test like new!"

Or somebody might look under the chassis and say "man, look at all those old wax-covered paper caps, I'm going to replace every one of them before I even think about turning this set on."

jr

Ps I have substituted .001s for .00047s for horiz output coupling an electrostatic set before with no problems.

[bandersen]

Originally Posted by jr_tech

Or somebody might look under the chassis and say "man, look at all those old wax-covered paper caps, I'm going to replace every one of them before I even think about turning this set on."

jr

Ps I have substituted .001s for .00047s for horiz output coupling an electrostatic set before with no problems.

I suppose I could leave a note inside the set

Originally Posted by bkharris

Looking at the schematic for your Hallicrafters 506 6au6 type late chassis those two vert sweep coupling caps should be .03 at 6000v
However I am not certain that the late chassis schematic is the exact chassis you have.

Interesting. Any idea how the chassis run can be determined ?

[bandersen]

I think I may have solved the little mystery with the vertical coupling caps. I discovered that the mounting band on the 0.005 has been cut and soldered back together. I bet it's a replacement (and a poor one at that).

[bandersen]

I managed to gut the old electrolytics. I think I can salvage the old tubes and some of the wax. The tar filled one was really nasty



Also, the new parts have arrived. I chose carbon comp. resistors to retain the original look. I couldn't find 0.03uF 6000v caps so went with 0.022uF. I think they'll be close enough.

I finally got a high wattage gun too. I hope it works well on chassis connections.

[Sandy G]

Eeeeuwww, what a nasty Meckin' Fess...(grin)

[cwmoser]

Originally Posted by ChrisW6ATV

Nice job on the caps. Decades from now, someone is going to own your set and say "How could those old wax caps still be good? They test like new!"

I admire your attention to authenticity. Really impressive. I've thought about re-stuffing capacitors but when I do I have this premonition that when I die and my estate is auctioned off to the highest bidder, in box lots and bags full of course, that my radios are bought by other collectors who will be conscientious and pull the chassis and note "hmm, never been recapped" and begin recapping the sucker without even powering up the set :-)

Put a note inside your cabinet telling what you did.

Carl

[bandersen]

It wasn't much fun, but it's done

I was able to reuse 3 of the old tubes, but the tar filled one was just too nasty. So I fabricated one from scratch.
Luckily, I had an old gift wrapping paper tube that was exactly the same diameter.





I reused the old wax to seal them.


I applied some yellow ochre acrylic paint and created a water slide decal.


Here's the final product.


Restuffing an old tube. I made a point of using the same colored wire so the tube legend is correct.


All four are finally done! I think the rest of the set will go fast now.

[Phil Nelson]

Well, you are a saint to lavish such attention on a lowly Halli. To make the disguise really convincing, now you can roll the new cap in that cookie sheet of old melted wax & tar

Phil Nelson