Frankenrola

[bandersen]

Here's a closer look at those cans. Very nice


Other repairs aren't quite so nice. I better double check the correct values on those caps that are doubled up.


I wonder where that ground lead used to go
Plenty of multi-colored heatshrink tubing all around.


Overall it looks pretty good. I'll need to dig up a field coil speaker to try it out. Or maybe a PM one and use a power resistor in place of the FC.

[leadlike]

Those can condensers are very expensive. I would have thought he would have done a better job on the rest of the chassis, though. My guess-guy restored radios, and this was his first tv. I know the first tv I worked on was slopped together pretty bad, too.

[dieseljeep]

I always wondered why Motorola painted the one side where the power supply components were. Possibly to run cooler? They only did it on the earlier models. Dave.

[bandersen]

Originally Posted by dieseljeep

I always wondered why Motorola painted the one side where the power supply components were. Possibly to run cooler? They only did it on the earlier models. Dave.

Good question. Cooling, insulation, "keep away" warning ?

I picked up a set of NOS knobs from peverett. Even they suffer from the white crud syndrome.




That cleaned off easily with a little 409. I then spent a lot of time polishing up the outer knobs.
They looked so bad at first I was convinced they were just plated steel.
Finally after a lot of buffing with Simichrome, the brass started to shine

[DaveWM]

nice cans, do the ones with out the cardboard tubes have voltage on them? I assume with the wafer it had a float ground or they were hot compare to the chassis.

[bandersen]

They are at a floating ground potential. This TS-60 chassis is a hybrid design. The B+ supply uses an AC line voltage doubler (the cardboard tube cap and seleniums).

However, there is a 6.3 VAC transformer for the filament supply. So no worries about current surge or uneven heating of cold filaments

[Tubejunke]

Originally Posted by DaveWM

nice cans, do the ones with out the cardboard tubes have voltage on them? I assume with the wafer it had a float ground or they were hot compare to the chassis.

Yes, he is lucky to have landed that set with golden caps in it. I notice that you addressed a floating ground signified by the "wafer" or insulating base at the bottom of the cans. I bet a LOT of troubles have crossed these forums posted by people who assume that all electrolytic negative sides (outer metal can) go to the chassis for grounding. I almost made this mistake once before a lot of formal training. Honestly, I have not studied the circuitry enough to know why some manufactures did this or what would be the result of a mis-connection. Do you know much about this Dave?

[bandersen]

Here's a nice intact version of this set on ebay: http://cgi.ebay.com/Vintage-Motorola...-/220726860074

Now I know what it should look like including the back I wouldn't take a chance shipping it, but maybe someone can do a local pickup ?

[bandersen]

With my Motorola 12K2 project and it's oh so similar TS-53 chassis fresh on my mind, I decided to try firing it up.



I removed the 16KP4 and put it out of harms way.


I first tried powering it up with no speaker field coil so no B+ for the set. The tube filaments lit up just fine

I'm missing the original FC speaker for this set so I'm going to use a power resistor. I measured the FC resistance in my 12K2 speaker and got 90 ohms.
I went with a 120 ohm power resistor for a little safety margin. I also used an 8 ohm PM speaker.


That got me a nice raster, but so sound or video. All the tubes were pulled from a working set set I'm pretty sure they're OK.
I noticed that the previous owner hadn't replaced a single resistor and a few old caps remain so I'll start checking & replacing those.

Here it is with an 8XP4. At least the HV is nice and strong.

[bandersen]

I fed a video signal directly into the grid of the final video amp stage. No image if I feed a signal into the IF stages. I think the fault lies somewhere around the detector.

[Electronic M]

Detector early SS detector diodes(if that is what your set uses) can and do go bad occaisionally. I'd try a replacement.

Tom C.

[bandersen]

It uses one half of a 6AL5 with the other half unused. Unfortunately, I was doing a little tube swapping and lost the test pattern altogether. I hope it's just a bad connection somewhere.

[bandersen]

It took me a couple days to figure out that this choke was open
It connects the IF strip to ground. Without it in the circuit, the cathode voltages were all way off.


I also noticed that the 6AG5 tube wasn't lit up anymore and discovered another bad choke in the filament supply.


I bypassed all of them with some clip leads.


Finally, some video The sound is good too.
I'm not sure if I have any suitable chokes on hand. I wonder how critical the value is

[bandersen]

The original reason I picked up this chassis was to use this 16KP4 in my Sentinel. So I'd like to adapt the chassis to hold a 17BP4 like this.
I think it will fit a little better in the screen bezel and I have a couple spares.
Perhaps I can bend the old bracket or make a new one from scratch.

[wa2ise]

Originally Posted by bandersen

I'm not sure if I have any suitable chokes on hand. I wonder how critical the value is

Not at all critical. Similar to a decoupling bypass cap. Anything vaguely resembling the value will work.