StrombergvCarlson TS-10 "Rochester"

[bandersen]

Just picked up this set locally off FB marketplace for $85. Already have a couple similar SC sets, but this one is the nicest. Veneer is in good shape and it has the metal back. Looks very clean inside. Only missing the focus knob.

Why is the focus control always messed with on these RA-103 based sets?!?

That's all I know so far.

Same cabinet as the 12" version. They just added a big bezel around the smaller CRT.





Previous owner?




Looks like it has the earlier "Inputuner" rather than an "Inductuner"

[Electronic M]

I've had that exact model with the 10BP4 and it's matching mask and wood block for many years. Definitely my favorite RA-103 cabinet style.

Those focus controls are often open from corrosion or possibly lytic or candohm shorts so it makes some sense that they are often messed with.

[bandersen]

Pulled the chassis and inspected it. Filthy but all original.






Freed up the frozen tuner with WD-40, cleaned and lubed. Unfortunately, someone must have cranked on the frozen tuning knob and ground off about 15% of the phenolic gear teeth!


Amazingly the relay, focus wirewound control and all the candohms are good.
Proceeded to do a slow power up and actually got a raster.

[bandersen]

A partial recap resulted in a stable image.

[Yamamaya42]

I was kinda surprised that both of your "Coke Bottle" 5U4Gs were toast.

They are just too neat looking not to have in there.

I still have a few of them in my sets, including one in my newer Stromberg Carlson, XP-21.

[bandersen]

I might put the duds in and install silicon power diodes below. B+ delay relay makes that a good option. Otherwise, the tubes would get hit with full B+ before the filaments had a chance to warm up.

[old_coot88]

Actually the purpose of the delay is to protect the electrolytics from being overvolted before the tubes start drawing the B+ down.

[kvflyer]

Originally Posted by old_coot88

Actually the purpose of the delay is to protect the electrolytics from being overvolted before the tubes start drawing the B+ down.

I guess one could install electrolytic capacitors with a higher voltage rating if this delay was troublesome. But heck, that wouldn't be original and what do we strive for? Originality, that's working originality.

[Yamamaya42]

I love the smell of exploding electrolytic capacitors in my television, it smells like, victory! NOT!

[bandersen]

It has a 700 volt electrolytic right after the 5U4s (two 350s in series with equalizing resistors). I really don't think over voltage is a problem.
I'm considering using solid state diodes to cut down on power consumption and give the power transformer a break.

A nice effect of having the delay relay is when the picture does appear it is already synched.

[old_coot88]

If the pic isn't in sync when it appears, there is a weak or borderline osc. tube, whether horz or vert.

[bandersen]

It's been my experience most sets need a few seconds to warm up before the image syncs and you see that on the screen.

With this set, the tubes are all warmed up when B+ is applied so the image instantly appears bright, sharp and locked in when the relay clicks.

[Yamamaya42]

Neat idea, not sure why they did not do in their later sets.

[kvflyer]

Originally Posted by Yamamaya42

Neat idea, not sure why they did not do in their later sets.

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