TRK12/120 Restoration

[decojoe67]

Originally Posted by dtvmcdonald

The restored cabinet.


http://www.videokarma.org/attachment...1&d=1434331611


http://www.videokarma.org/attachment...1&d=1434331611

Very nicely done. It has a smooth semi-gloss finish that looks very original. It's so fortunate that John Vassos was chosen to design these cabinets. They have a very clean machine-age deco design.

[dtvmcdonald]

I just looked again at the pictures of my cabinet. The front-on
one is absolutely bizarre, I didn't notice! The left and right hand sides
are not symmetric in shade. But .. they most certainly are
quite symmetric in person. I've never before seen my camera
do something like this.

[Eric H]

That is some really nice cabinet work!

I've notice Veneer tends to reflect light unevenly, probably because of the bands of grain, that's what makes it so attractive though.

[dtvmcdonald]

Finally all necessary parts have arrived. Posted is a photo of the radio chassis in its current stats. That is, rust removed, missing the motor capacitor, and the Candohm and three brodcast band coils (hopeless) detached from their moorings. All paper caps are unrestuffable,
Steve McVoy has graciously sent me defunct ones with healthy cardboard cases. Most sections of the Candohm were long ago open and bridged.
Plastic insulation has crumbled. But the motor drive is fixed and works perfectly (with a suitable cap clipped in of course).

[decojoe67]

Originally Posted by dtvmcdonald

I just looked again at the pictures of my cabinet. The front-on
one is absolutely bizarre, I didn't notice! The left and right hand sides
are not symmetric in shade. But .. they most certainly are
quite symmetric in person. I've never before seen my camera
do something like this.

The flash of a camera can often bring-out things that cannot be seen under normal lighting. Sometimes it can really compliment a cabinet, other times it's unflattering to it.

[ChrisW6ATV]

Your cabinet looks very nice after the restoration work. What a contrast from when you started.

[dtvmcdonald]

I'm 40% through recapping the radio of this monster. So far only one resistor
was over 18% high and it was 1.5 Meg rather than 1.0, the 6A8 2nd grid resistor, so I left it.The area around the can electrolytic is a nightmare so
I'm not restuffing it ... in any case no one will notice as their eyes will all be in the area of the former Candohm.

I am restuffing the paper caps, but even with McVoy's generous stock
of old ones I could not always use the original size bodies as some diameters
were too small. Nor do all the ends look right ... I'm wondering: will
painting the visible ends (which are hot glue) black with acrylic paint be OK?
Will it flake off?

[bandersen]

Acrylic should be OK. Probably too late now, but you can get hot glue sticks in many colors including dark brown similar to the original wax.

[vts1134]

Originally Posted by bandersen

Acrylic should be OK. Probably too late now, but you can get hot glue sticks in many colors including dark brown similar to the original wax.

I use a dark brown hot glue to hold the new capacitor inside the old shell. It looks very close to the original wax, but to get it to look even better I actually save the wax that I removed from the old cap. I fill the brown glue almost up to the top of the cap and then melt some original wax to "top it off" at the end. Using this method makes the re-stuffed cap look so good that I have to mark the caps I've replaced because I can't tell them apart.

[Sandy G]

Oh, man, that cabinet is "To Die For" pretty ! What does the CRT look like ? Its one of those 3-4' long jobs, isn't it ? You're STILL a VERY lucky man...

[dtvmcdonald]

These are not wax caps. They are either the kind with the little paper
disk at the ends with the cylinder ends rolled over it, or paper tubes
sealed at the ends with some sort of black hard substance that
does not melt at a temperature low enough to keep the paper
the original hue. They can, however, just be pulled out.

I had to remove the volume and fidelity controls
to get to parts under them. I've decided to replace all parts under them
with new ones because this is such a hard chose.

I was able to leave lots of old rubber wires in the RF section alone
because they dangle quite safely in air ... but in the audio section
100% of the non-cloth wire will have to be replaced.

I got like three caps replaced today ... the rest of the time was spent
in disassenbly, rewiring, and having to go back to campus to buy
a new soldering iron tip since my local (5 minute walk) Radio
Shack was sold out.

[dtvmcdonald]

Originally Posted by Sandy G

Oh, man, that cabinet is "To Die For" pretty ! What does the CRT look like ? Its one of those 3-4' long jobs, isn't it ? You're STILL a VERY lucky man...

The CRT is less than two feet long by a little. Its one of the
refurbished aluminized radar tubes. I have not taken it out of its carton.
I have a 12LP4 to use for testing.

I too am pleased with the cabinet. Except for the side
pieces of veneer on the front it was not in too bad shape overall,
just scratched, needing sanding. Also, there was a large chunk out
of the wood cover that fits over the CRT which needed filling in and
covering over with new (and very sharply bent) veneer. They guy was
able to match the original veneer closely enough that he didn't
need to redo the other side. Only the bottom front and back pieces
(plain wood no veneer) were badly water damaged and were replaced.

[dtvmcdonald]

Little progress today. Two resistors replaced, two rotted wires,
and mostly repainting a whole lot of resistors. I painted the bodies tonight;
tomorrow morning I will paint the end and ring (these are not B-E-D
color code but B-E-ring). I'm using ordinary modern resistors, not
worrying about size as the set had a wide variety of sizes.

Doug McDonald

[dtvmcdonald]

I got the radio working. 80% of resistors, all capacitors, and 40% of wires were replaced.

I first turned it on with no tubes at all inserted and nothing smelled bad, the
motor tuning still worked. Then I inserted the 5U4G and found that the second-level
HV was too low. It turned out to be what I worried about: I did not restuff the
electrolytics, but hid replacements. One was rather close to the fidelity switch,
and I was afraid to bend the switch contacts too much, so it shorted.

I unsoldered the offending switch lugs and redid them, leaving 1/8 inch
spacing which is fine for this voltage. This fixed that problem.

Then I removed the 5U4G and inserted all the other tubes. No heaters.
I had not used Deoxit on the plug that delivers power to the main chassis.

Then I tried running everything inserted on a dim bulb. Nothing smelled
or showed signs of a short. Setting the switch to TV or phono and touching
the input showed the audio worked.
Setting to radio and tuning around shortwave produced little (the broadcast band
coils are defubnct, that has to wait til tomorrow.) Attaching an antenna
resulted in absolutely normal shortwave reception!



chassis pictures tomorrow.

[dtvmcdonald]

I got the radio finished. The bcb oscillator coil was replaced with
a Meissner "universal" one. The other atnessna and Rf amp plate coils
were rewound. The set now works quite well.


Pictures are, in order, a view under the fidelity switch, after reworking.
Next is the finished bottom, then the front, tghen the top.