I read this in a book printed in 1964 it says that the average life is 3 and a half years some more or less .
I have got far longer that this on many old televisions , most with original CRTs and how many hours on them before I got them I have no idea .
My 1954 crosley has been running about 4 hours a day for a year and a half with no sign of any loss of brightness , it has a 17HP4 in it .which looks to be the original
I have used one tube tv for over 8 years , more or less 4 hours a day on a used replacement CRT that I got from another set . This set was made in 1974 . Perhaps there were improvment to CRTs by this time, it has gotten no dimmer with this use .
this has a 12VAEP4 and it has the rapid on system so that the filiments are lit all the time .

What's your experiances with CRTs

I say they last MUCH longer than 3.5 years. Both old B&W and color up until at least the 80's.

I recently removed the original crt from my 1956 Philco that has had a booster for the past 25 years that I know of. It came with the set when I bought it in 1982.

Also in 1982 my Dad brough us home the superb at the time 27" Sears color remote console. I still have in in my living room because it wont quit. Now this set has seen MANY hours of constant use and the crt is as bright as the day we brought it home in 1982. Sometimes I wish it would die so I can make room for some older set. A guy has been holding a round tube color set for me for several years and I would rather have that. My humble home just aint cuttin it as a warehouse....

The last repair bill for my 1955 zenith bugeye was taped in the back, dated 1977. The set was almost twenty two years old back then, and its still on its original CRT, which is just now starting to darken, albeit rapidly.

I think they might have been covering their assets! :lmao: if they predicted a life of 10 years and yours failed at 3 years you would be &!$$#). It would build pride in knowing that your CRT lifespan was way much better than the average 3 years expected.

I think they might have been covering their assets! :lmao: if they predicted a life of 10 years and yours failed at 3 years you would be &!$$#). It would build pride in knowing that your CRT lifespan was way much better than the average 3 years expected.Good point .
I've had that book for over 10 years and have watched many crt's pass the 3.5 year mark .
This was a TV technician that wrote this and I am surprised at his findings .
I thought this would be a interesing topic . :D

Really depnds on the quality of the tube. I do know that the average CRT goes downhill slowly. Poorer quality ones (IE: 1990's Zenith's) probably start noticeably going downhill after two years of regular use.

Another factor is in how many hours it has on it. Some CRT's will go on for hundreds of thousands of hours. Some might last only 20,000 hours. (Somebody told me that a year was about 8700 hours). If it's left on 24/7, it will go downhill faster then if it's only played 4 or 8 hours a day.

Luckily there's usually lots of adjustments to compensate for the aging of the tube. In older sets this is the case anyway. So far, certain Sony Trinitrons have had the most adjustments that I've seen.

I'd say that a tube is good until it starts to have color bleeding, or for a black and white tube, gets too dark to be useable.

Certain makes or types of tubes did worse. Here are my experiences: 10/12" round tubes hold up well, as do most of the 21" crts from the mid-50s on. The most troublesome tubes seem to be the larger metal-cone round tubes, 15/17" rectangulars from the early 50s, and the tubes used in electrostatic sets. RCA tubes seem to hold up the best overall, along with Zenith color tubes from the 60s/80s. I have also had good luck with GE tubes. I have had multiple weak bw tubes from Sylvania and Zenith.

I doubt any of us will use a set enough to weaken a tube, at least not in just a matter of a few years. If the tube is weak, it got that way decades ago from hard, daily use. Dad turned the set on at 6am for the weather, the kids watched Captain Kangaroo, Mom watched game shows and soaps all day, then the kids were back to watch cartoons 'til Dad sat down to watch Walter Cronkite, and then it was primetime, and later Dad would fall asleep in his easy chair, awakening after midnight to turn the set off. Repeat this 365 days a year and eventually you'll weaken that tube pretty good. A few years ago I got a pair of consoles from an old farmer I know. One is a Silvertone he bought new in 53; it has a rebuilt tube in it, which is weak. The other is a Motorola he bought new in 60, also with a weak tube. He had replaced that set with a color model (long gone) in the mid-60s. So, in 7 years the Sears set ate 2 tubes, followed by the Moto which made it 5 or 6 years. He had several kids to help use up those sets.

It definenly has a lot to do with the hours on the tube , and the model .
The thing is with most of us is , most of us have at least 10 sets to run at any given time so even with this 3.5 year life expectancy were ok for 35 years yet .
The tvs that I notice weak picture tubes in are the 21" Hitachi color sets from the late 70s early 80 , they are dark and then they bleed colors when you crack up the brightness . the nicest is the Zeniths and the KV1710 sonys
but these are not early tvs .

My '68 Magnavox color console that I started the thread on in the rectangular tube and solid state forum has a Zenith Chromacolor tube which had a two year warranty on it and was installed in '72. The tube still checks very strong on all 3 guns and passes a life test on my B&K 480 tester. The only thing wrong with this tube is that is has a green halo around the edges. Otherwise, I see no reason why it won't make a nice picture once I get the set going again. Of course, I have no way of knowing how many hours were put on the set in the past 35 years; but, I think this tube will hold up well for years to come. IMHO, the delta gun Zenith tubes were some of the most reliable tubes out there. I've seen numerous makes of B&W tubes that were still nice and bright after 30 or 40 years. I've also seen just as many weak / dead ones. Most of the weak ones from the '70's on back responded well to rejuvenation. I think the worst B&W tubes I've ever seen were in the Emerson, GoldStar, and Samsung 12" sets from the mid to late '80's. Most all of the one's I used to find were very weak and would not respond to rejuvenation very well.

My '68 Magnavox color console that I started the thread on in the rectangular tube and solid state forum has a Zenith Chromacolor tube which had a two year warranty on it and was installed in '72. The tube still checks very strong on all 3 guns and passes a life test on my B&K 480 tester. The only thing wrong with this tube is that is has a green halo around the edges. Otherwise, I see no reason why it won't make a nice picture once I get the set going again. Of course, I have no way of knowing how many hours were put on the set in the past 35 years; but, I think this tube will hold up well for years to come. IMHO, the delta gun Zenith tubes were some of the most reliable tubes out there. I've seen numerous makes of B&W tubes that were still nice and bright after 30 or 40 years. I've also seen just as many weak / dead ones. Most of the weak ones from the '70's on back responded well to rejuvenation. I think the worst B&W tubes I've ever seen were in the Emerson, GoldStar, and Samsung 12" sets from the mid to late '80's. Most all of the one's I used to find were very weak and would not respond to rejuvenation very well.I know what you mean , I picked up a late 80s goldstar , it was so dim it was not watchable even with the lights out , there were some sears tvs in the 70s made in Korea , they were known to have bad picturetube ,
Tube Sears portable TVs 12" to 16 " in the late 60s and early 70s were good , I think they were made by sanyo , im not sure . Does anyone know who was manuracturing these sets for Sears Roebuck ? they had a gray colored cabinet , they stood up really well .

I've had several different portable Sears B&W sets from the late '60's through the '70's. Some were made by Sanyo and some by Toshiba and the CRT's were still decent in the one's I used to find.

Most of the CRT's in my collection were either good anyway or came back after a nice cook. Two of my Philco sets ended up seeing the Beltron after the long cook had little effect. Both came up nicely after a short pop with the rejuvenator. Same is true of my Westinghouse. The CRT in my Predicta was DOA. One of my RCA Victor sets has an open heater (16GP4). Otherwise, the rest came up or were already good.

Most british-made big screen Sony Trinitron CRTs from the 90s are crap... i have yet to see a good one...

Late 80s and 90s Philips 45AX CRTs (their first CRT wih square corners) are also prone to failure...

Videocolor (RCA) self converging PIL CRTs from the mid 70s-onward often develop a blurry picture and poor grey scale early in their life... if you ever take apart an old PIL gun, you'll notice the severe enlarging and deterioration of the G1's pinhole due to metal evaporation.

On the other hand, i have yet to find a bad Philips CRT made before 1985 or so...

I think the worst B&W tubes I've ever seen were in the Emerson, GoldStar, and Samsung 12" sets from the mid to late '80's. Most all of the one's I used to find were very weak and would not respond to rejuvenation very well.

I just received the GE 12" B&W I won on Ebay. I was afraid the CRT might be weak after all, it is a thirty year old set but to my surprise, the tube is as bright as new. Excellent contrast and brightness. The set was obviously used as the silver paint on the volume control is worn off. In all the sets I've had, rarely have I had a picture tube go bad. By the mid to late '80s, quality in 12" B&W sets had gone way down. The best 12" B&W sets seem to be from the early '80s on back.