Is Heat Public Enemy Number 1 ?

[VA561]

I have read in a few posts that the heat generated inside a vintage tv cabinet is ultimately responsible for most component failures or tv problems in general. Is there any benefit to trying to cool the inside of the cabinet by means of some sort of fan while the tv is on? I was thinking of a small computer fan or something similar attached to the back cover to draw out the excess heat. Anything that will prolong the life of my old sets would be a plus. I currently play my 1950 Philco 50T-1404 and my 1960 RCA color set, the "Randolph" model 212G886MV, about 2-3 hours a week. Any thoughts on how to combat the heat issue?

[Einar72]

Fan without filter = dust buildup. It's easier to filter the air going in than fishing dust out of everywhere, so a pull-through fan on the hot end of the cabinet would not be my first choice. Use your PC as an example; pulling air out fills every crack, crevice and drive opening, and it's pretty fine particles usually. Choose the in-flow location carefully, and you'll be breathing extra years of enjoyment into your precious roundie!

[miniman82]

Only thing I bother to cool is the HV cage, mostly to protect the unobtanium flyback.

[TerrySmith]

My dad would simply remove the back cover and leave it off from day one. He said it seems to run cooler that way.

[TV-collector]

Not in general.
Sometimes a lousy construction results damage.
Take care that tubes don`t heat up caps, elytics or diodes.
To save money companies used resistors which are hot from the
first day, try to use resistors which can stand a higher current and place
them carefully on the chassis not to heat over parts.
My Tandberg TV 1 (AC/DC chassis, transformer) has burned knobs, just because the main resistor
produced too much heat.
Before I install good ones (same knobs like Telefunken because made
in Germany) I will make some changes in the power plant.
My Raytheon Porthole had a totally burned transformer, my transformer
rewinder told me, that it was wrong constructed.
He said that it makes him wonder that this transformer survived more
then a week.
We call this in Germany a "monday set", produced on a monday.

Best regards

TV-Collector

[Phil Nelson]

Putting on my contrarian hat, I have restored a number of 1940s-1960s TVs, and I haven't seen a lot of obviously heat-related problems in the older ones. Those TVs were designed to operate without extra ventilation and many of them played for hours every day, year in, year out.

If you visit the ETF museum in Ohio, you can see some of their sets playing for hours at a time. I haven't noticed extra fans or special cooling on any of them.

In some newer sets, late 1950s to early 1960s, I have seen issues like toasty PC boards around tube bases. A cramped set like a Philco Predicta might benefit from extra cooling, as would a color roundie whose flyback was questionable in the first place.

Old capacitors and resistors degraded over time, but this is a function of age (and invasion of water vapor, for caps) more than heat. NOS caps and resistors that were never installed have the same problems as those that saw use.

All in all, I think moisture is a bigger enemy than heat. Playing a TV a few hours every week, as you're doing, is better than letting it sit idle, since the heat of normal operation helps to keep things dried out and happy.

As Einar noted, an unfiltered fan may carry a lot of extra dust into the chassis. I have cleaned out old computers that were seriously clogged with dust. That stuff didn't grow legs and walk inside; the fan brought it in.

Just my $0.02.

Phil Nelson
Phil's Old Radios
http://antiqueradio.org/index.html