I was putting the 1960 Magnavox back together, and was wondering
if leaving the back cover off would be better for the set?
Does it make it cooler?
I also thought maybe a small fan installed would help?
Unless all the heat in the back is normal, and this was built to tolerate it-

Interesting. Hard to say what's best. Unless you wanna run the set all the time, I'd think that leaving the back on would be better-If for no other reason, it would keep stuff outta the "Innards" that doesn't belong there. These guys WERE designed for a non-airconditioned world-And a world where EVERYONE smoked, which couldn't be good for all the gunk that accumulated on 'em back then.

i thought about doing that, but i think it might drag more dust than normal threw there with the static charge allready there it might load up pretty fast . maybe if you put a fan at the top of the back facing out ,and slow it down so you only just pull the heat off might work. try it let us know, use a small computer fan i think the 5in fan pulls about 75 cfm slow it down to about hafe.

Unless all the heat in the back is normal, and this was built to tolerate it-It's normal for a tube TV or radio to give off heat, and if it has a cover, that's how it was designed to operate. Millions of people played these sets for years without installing special ventilation fans.

If you install a fan that isn't filtered, you may just bring a lot more dust into the interior than otherwise.

Just my $0.02.

Phil Nelson

hay you can use it as air cleaner just keep the shop vac handy once month. LOL

They were designed to run hot and did for years, but with how many service calls? I cant say how many of those calls were due to heat related issues but I am an electronic tech and can say heat is the main enemy of electronics. We install computer fans in many cabinets where multiple components share a space. Of course you'll have more dust drawn in as the side effect of more air, but if there isn't a lot of smoking around I think the dust effect will be offset. I'd put a fan in there if it was mine and I were using it as a daily driver. A lot of modern electronics such as computers and receivers have fans.

I don't think a fan would be required for the common B&W 50's sets, they actually don't put off too much heat. It's the older 50/60's color sets you have to worry about, they consume literally twice the power of a similarly sized B&W one. Like Bob G, I will be installing small muffin fans into the HV cage of all my color sets soon. It should help guard against flyback overheating, since those parts are unobtainable now.

I agree with miniman82, I leave the b/w sets alone with the back on. On the tube color sets I also put a muffin fan on the HV cage. I don't hear it when the set runs and after 2 or 3 hours of use the flyback is cool and there is no more dripping wax. I feel that since the old color flybacks are getting hard to come by this will extend there life. It is still important to properly restore a set and get the cathode current set correctly.
Mike

Another factor to consider is whether your line voltage might be higher than in the era when a particular set was new. Wattage (and heat) don't go up linearly with voltage, since volts X amps = watts. F'rinstance, if a set drew 1 amp at 110V, wattage is 110 watts. But if voltage is 125V, amp draw will be 1.25. Ergo, 125X1.25 = 156.25 watts.

Hi to All,

I'm a big believer in cool electronics run more reliablely and frequently use add-on small fans.

I rember reading in a tech book 30 yers ago about component technology, sorry, can't remember which one (French book) that everytime a component's temperature ran 10°C higher, long term reliability was halved - statistics over thousands of hours of operation & study of failure causes.

It profoundly affected me, and to this day anything i build/modify/service follows those guidelines.

Simple everyday experience: open any item using fixed 3 pin +5, +12 VDC regulators and check their temperature. Many are shockingly hand-burning hot and run with no heatsinks nor fan. In my book, very shoddy designing indeed.

When possible, i try to re-locate these regulators to use a metal chassis heat sink with Mica/Ceramic electrical insulation.

Opening a can of worms here - just my 2 cents...

Best Regards

jhalphen
Paris/France

Another factor to consider...line voltage



That's why all my sets run on my isotap tranformer, I can dial in the exact voltage the set needs regardless of input voltage. Just turn the set on, wait for it to warm up, then read voltage going in to the set and turn the knob till it's right. 117VAC every single time. This is also important because convergence can be affected by input voltage, but the main thing is to keep horizontal output tube cathode current as low as possible to protect the flyback.

If you have pets or kids, I'd sure put the back on that set.

If child/pet proofing is not an issue, cooling can help the long term life of electrolytic capacitors, but if you have already recapped with high-rated ones, they may outlive you anyway. Miniman's thoughts on flyback temp are worth considering, but I'd guess that a poorly adjusted horizontal section is going to overheat and fail no matter what kind of fan you install.

Yeah, heat may be an issue affecting reliability in the long term, but consider the following:

We recap our sets new with tubulars and electrolytics which are many times more superior than their 40's and 50's forebearers. They certainly can take the heat. I use 105 degree centigrade electrolytics whenever possible, and there are few values I can't get with that temp rating.

We use our vintage Tvs what, an hour or two at most per day? Certainly not 5-6 hours daily like we did when they were our primary television receiver.:smoke:

My Maggie color roundie combo runs all 32 tubes while using the TV. Overs 400 watts!! It's gonna get a small fan before the back goes back on even though the cathode current is only 190. Flybacks are very rare for these and I want to use it several times a week. Prolonging it's life is a must

while we are on the subject of heat , i have seen alot of different brands of electrolytic's out there for sale ,from exper. witch one's last the longest now days handle heat the best . esp. in a tube envirnment alot probley come out of china with different names but are made by the same people im assuming . im used to the older manufactures ,but you dont know who owns them now or making there product for them. like miec / g-luxon and so on . who has had or have not had problems with some of brands . list from best to dont waste your money

I use Nichicon and Panasonic 105 C 'lytics whenever possible. Sometimes the blue Spragues. All of those are great 'lytics.

But, I didn't think of all those micas, ceramics, and other parts which are 60 years old now. Maybe a fan would be a good idea, particularly if it was going to be used for hours on end...:smoke:

I have a 1956 Philco 21" table model that I bought in 1982 from a local Goodwill store for use as my first bedroom TV as a teenager. Peeping in through the back cover and seeing what at the time looked like a small city of light led me to remove the back cover so I could see better and more easily clean inside and occasionally take some tubes to Radio Shack to use their tester. The set is now in the room next to me all of these years later and I wouldn't hesitate to watch it for the evening. It has never been restored nor shown a sign of needing it! I do wonder if the lack of a cover helped this set to be a MEGA performer. The circuitry outlived the CRT which I replaced a few years ago. The only bad part is I no longer have the back cover which got discarded by my dad when I went in the army. So far I have had no luck locating one and I would like the set to be complete. The Philco is about as plain Jane as they came, but it is my crown jewel. Having been with me through over half of my life and serving its purpose for almost 60 years, I can't ever see getting rid of it.