Cold
 

What are the ramifications of storing a roundie in 32F temps or below? I can assume this is a bad thing to have to do although I may have no other choices.

The electrolytics may get unhappy, but the goop may act like antifreeze to keep the water from freezing.

Don't forget that TVs likely sat in cold warehouses, freight trains in winter near Frostbite Falls MN, and in trucks there too. So sets had to be designed to take it. Not necessarily powered up and take it, but just take it while off.

Don't think it will hurt them. When brought in from the cold, they must be allowed to warm to room temperature before turning on so that the condensation that forms when they first come in can dry up.

I haven't heard of problems with cold storage (but I agree on letting it come to room temperature for a day to dryout any condensation). Some early sets with solid-state horizontal outputs had problems if stored in very humid places (like a warehouse in New Orleans) for a long time, because the flybacks would heat up rapidly when turned on and boil the absorbed moisture, exploding the donut. Better flyback design solved this. Tube sets would limit the current more and just not perform correctly until the moisture was eliminated.

Agreed, long term moisture is an enemy but cold won't kill a roundie. The 21FJP22 in my CTC-15 spent 10 winters (at least) face down in the woods. Aside from losing the aquadag, it's fine.

Dean you can store it at my house, I'll keep it warm watching it.

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My original CT-100, B8000173, was in cold storage from 1985 to 1999 in New Jersey. There seemed to be no specific electrical deterioration (although the vertical convergence transformer failed soon after it was returned to service), but the cabinet definitely took a hit.

we had a set on the back porch for awhile back in the 80s.we brought it in on the coldest day in columbus history:-18 degrees with winds blowing at 20-25 mph.for some reason,i decided to turn it on.ice on the crt face.it came on and played all day!i was lucky and never tried such a stunt again.cold is fine,just let them warm up before you operate.

Larry you might want to head up this way I can give you the knobs I owe you and you can possibly take a few other things home. I will store what I can it sounds like I can hold on to a few in the cold:) I would say the vote is unanimous that they can survive it.I am moving to another location with much less storage available so some have to go somewhere at some point.

It cracked me up to see a rebuilder here in New Jersey (now long gone) who used to store his excess "inventory" of dud color and black-and-white CRTs out ON THE LAWN! Face down on a piece of cardboard or some right on the lawn. Summer and winter. Apparently they were none the worse for wear for it as he would bring 'em in, clean 'em up and rebuild 'em as needed. It was a bit surreal; I wish I'd have thougth to take some pictures.

Not to imply that this was "best practices," of course. The whole shop was very dirty and disorganized. I wasn't surprised he went out of business a lot sooner than some other places.

Is this a good idea??

My ctc-5D set is in my garage at the house, unheated but pretty well insulated and dry. I tested the tube on my CR-70 last feb aNd it tests LIKE NEW!! I want to keep it like that, and so, since it is bitter cold now--I am kind of "warming" the CRT--and chassis.

This is done by running the set with the B+ disconnected(by removing the 5U4 tubes) and running the filaments on the other tubes--including the CRT--at a slightly-- reduced input on a variac--maybe 100 volts or a bit less. This draws a bit under 3/4 amps from the line or so, and the CRT filament and the heat from thew other tubes on the chassis--SHOULD hopefully keep the CRT warm enough, and keep the vacuum in it. After all--it would NOT have tested good--if it was leaking, right??

Or--is this a BAD idea--and should I just "let it be" without any warming?? would that be better for the tube--I can NOT see how it could be.

If your 5 still has the metal cone 21AXP in it I'd be very concerned about any extreme temperatures, hot or cold.

I would think expansion and contraction would be bad for that tube.

Yah, and I'd be especially concerned about sudden temperature changes. Metal and glass expand & shrink at different rates, so extremes of heating or cooling might encourage a glass-metal CRT bond to break loose.

Extreme example: Imagine that every day I bring my roundie indoors to play for several hours, and every night I wheel it outdoors to my front porch.

Not ideal because:

1. Big temperature change.
2. Changes are sudden.
3. Hot-cold cycle is repeated often.

For long-term storage, I'd try to keep things as constant as practical, avoiding abrupt changes. Within reason, it's not like your CRT "wants" to be at a particular temperature. It's more like that scene from Wayne's World:

"We fear change!"

:)

Phil Nelson

I think the whole cold thing is over-blown. The main concern is the moisture, but once you bring in a unit from the cold always let it warm to room temperature before power up.

Yes it DOES appear to have the original 21AX, since the safety glass is still in place, as is the plastic cover over the metal shell of the tube. The set is FAR from operational, and needs a full recap and such...., but is intact, knobs, back cover and all--and as I said--appears to have a good tube.


So, I should just unplug it--and "let it alone" I guess.

Hot and cold mileage,cold to hot and hot to cold
 

Located 620 road miles north of Seatle and a fetish for the round screen,I go to far away places and in a wide variety of temperature changes along the way. From North Dakota to southern Mississippi you will find the temperatures can vary a little bit. So far no vaccum losses including a CTC 5 from Chicago and a zenith port hole w/12UP4 out of Connecticut My furthest pick up was around Bucksport Maine.

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Agree that cold storage probably won't hurt, but if you're gonna warm it, why burn the tubes? Hang a 75 watt light bulb inside the cabinet and throw some drop cloths over the set. All warm and toasty like Aunt Agnes in bed with her heating pad.

I think oldtvman has it right. Moisture is the biggest issue. All the CRTs went through at least 600 degrees F in the oven while they were processed, with a change from ambient to hot and back to ambient in only 3-4 hours. Much more extreme than any temperature delta they will see just sitting exposed to the heat and cold of ordinary weather. The expansion characteristics of the glass to metal joins were carefully engineered to expand and contract at the same rate. Otherwise, no CRT would ever survive being built in the first place.

Will be bringing in the ctc 9 I got from Dean to start restoration next week. It's been setting out in the garage. I'll let it set for 24 hours.

Cold
 

The worst cataract cases I've run across were sets stored in garages, including mine. (Michigan temperature extremes)