Hypothetical best performance from an all tube color tv

[Lain94]

This was just a thought I was wondering, and I figured people on this forum would be able to give a more informed answer to it than I could since I am very unfamiliar still with vacuum tube electronics. Are there ANY performance advantages a vacuum tube tv set would have over a solid state crt tv or even a LCD TV ect. (whether in sound, color, tuning, reliability, contrast) I know vacuum tube sound is supposed to be "warmer" but I don't really know the actual scientific or measured differences.

I know CRTs have very good refresh rates, so much so that many gamers from my generation are still aggressively seeking out many remaining CRTs to play high speed action based games on them since LCD screens seem to be rather laggy.

Thought experiment: A custom built all vacuum tube tv set with a modern trinitron style CRT with ultra fine dot pitch like in a high end computer monitor.

I know the ability or cost to make such a thing would probably be crazy high, but I can dream of such a thing right? lol

Regardless of whether there is any objective performance advantage I still am fascinated by how designers were able to make such impressive devices back in the 50s and 60s it is a testament to ingenuity and quality.

[MIPS]

I know CRTs have very good refresh rates, so much so that many gamers from my generation are still aggressively seeking out many remaining CRTs to play high speed action based games on them since LCD screens seem to be rather laggy.

This one has always kind of confused me. Your typical home TV will be optimized for general video reception to reduce cost and complexity. The refresh rate is locked and even then until progressive scan became viable the refresh rate depending on where you lived was locked to to the broadcast video standard because it was interlaced and pushing higher refresh rates over the air imposed timing and compatibility issues on older sets. Only when you got to station and editing-side did you start seeing external video sync what could allow for faster or unlocked screen refresh rates but that all had to be downconverted before broadcast. Beyond that you begin to see computer oriented displays where refresh rates go to 60, 75 120hz or more.

I've played games on a CRT, plasma, projection and LCD and I've always classified people who say the higher refresh rates give them a competitive edge to be candidates for going outside and getting a life because true as it can be, jesus christ get a girlfriend or another hobby. :P

A well tuned CRT though will deliver excellent contrast. Plasma could as well to an extent but LCD's especially in the CCFL era were always rather terrible. CRT's also allow for neat colorburst hacks to produce better colors than were available on older computers by doing things like blending lines. This is well documented.

More on to what you were suggesting, I'm not sure you could make an all-tube set drive a CRT at high refresh rates. Eventually your limitation is in how fast you get electrons passing through the tubes.

[Electronic M]

The 1954/55 color sets that used the 15GP22, it's 19" version and the 21AXP22 had wider color gamut phosphorus that resulted in a broader color space than later CRT sets...Those phosphors were dimmer than the newer ones that replaced them. Also many of the sets of the time were based on the CTC-2 chassis that had wide band IQ chroma demodulation...those sets were 40 tube monsters and tube count was reduced by limiting color reciever bandwidth (video detail).

Tube sets also have a serviceability advantage all the circuitry is discreet and all components are generic to the point almost everything can be substituted or in the case of inductors/transformers rewound.

The disadvantage is usually 6 Month -2year maintenance intervals.

An SD set from 1955, 65 or 75 can give an SD set from 1995 a run for it's money on picture quality.

If you like monochrome movies the best CRT experience you can get is a well aligned monochrome TV (or 60s era Video Tape monitor) designed to provide full bandwidth 4.5MHz video from the IF...Color sets typically limited monochrome video bandwidth to 3MHz to prevent color dot crawl....If you feed the luminance signal of S-video output (or the green component output) DVD or LD player or other SD capable source device through a modulator or via direct injection to a quality monochrome set the results will be better than any SD color set.

People have made electrostatic 7" sets into video monitors that will do 720P....It's harder with magnetically deflected sets as significant re-engineering of the deflection is needed to accomplish that.

It is possible to run a modern inline CRT off of a vintage chassis at SD resolution. Test jigs for TV shops made in the 70s and 80s would have an inline gun CRT and an impedance matching box to allow them to be connected to a disembodied console chassis from anything from a modern SS set with low impedance yoke to a 1954 color chassis using a high impedance yoke with the right adapter cables.

My daily watcher (and newest TV) is an 04 Sony KD-34XS955 HD-CRT TV with super-fine-pitch CRT...It supports 1080i as it's native phosphor resolution and scan rate (and can handle 720 and 480 obviously), has an HDMI input, 2 HD component inputs and supports ATSC 1.0 . It's really all the TV I need I don't watch anything in 4K and even if I did I doubt I'd be bothered by only seeing it at 1080i, it's contrast ratio and brightness have been better than consumer grade LCDs for years (it may have been eclipsed recently, but it doesn't matter to me). If you want ultimate CRT performance hit the gym, make a friend to help you lift it's 200lb girth and get one of these.

It's possible that someone with a LOT of time on their hands could take a CRT from one of these and build a tube sweep circuit and video amp that could take component video at 1080i (or even one of the K resolutions) and make it work. You would have to be a superb engineer with knowledge of high frequency tube circuits and access to custom transformer winding facilities to pull it off....... It's one of those "look mom I built a fully functional government safety standards approved 100KW nuclear power plant in the garden shed" level projects. It's not impossible, and there's probably enough people with the aptitude to do it to count on more than 1 hand...Whether someone actually will is the question.

[ARC Tech-109]

I'm working on a betacam set input for my Mag T940 chassis. Luma bandwidth is quite high after the 4.5 MHz sound trap in the tube sets and with the component set being phase based its not affected by the chroma bandwidth or color burst. It's a slow go right now but I'm not giving up on a tube based design for the sake of expediency. Big challenge is the impedance mismatch of the tube and the phasing.

[ARC Tech-109]

I also have a Panasonic CT34WX54 that's in need of a good home

[ChrisW6ATV]

Originally Posted by Lain94

Are there ANY performance advantages a vacuum tube tv set would have over a solid state crt tv or even a LCD TV ect. (whether in sound, color, tuning, reliability, contrast)

Referring strictly to the chassis/circuits as opposed to the CRT, I have not heard of any inherent reason that tubes could or would be better than solid-state devices for a TV set or video display.

As I am sure you know, professional color monitors going back to the 1953-54 beginning were capable of much better performance than retail-sold color TV sets, and one big reason is that they had higher-quality or additional circuits and components and, of course, a much higher price than sets made for home use. Using direct video inputs also bypassed the RF and IF system, which is a big bottleneck for overall video quality as well.

Those differences in professional versus home TV sets/video displays existed all through the NTSC era (and still do now, in the HDTV/4K/8K and beyond era), but I do not know of any way that just using tubes would result in a better quality picture --on any given CRT and phosphor type-- which is the ultimate limit of any display, even more than the speakers are the ultimate limiting factor in a sound system.

[LukeSimon]

The best way to understand the appeal of non-solid state TVs versus solid state CRT TVs is to make an analogy with clocks. A solid-state CRT TV is like a clock with a mechanical face, but an electronic quartz movement. The face of the TV is a vacuum tube, but the rest of the chassis is solid state. Similarly the clock's face is mechanical, but its movement is electronic & quartz.


A non-solid state TV is like a purely mechanical clock. Both the face and the innards are the same type of technology: tubes in the case of TV and mechanical components in the case of the clock.


I believe that one reason people collect non-solid state TVs is for the same reason people collect purely mechanical clocks. It is about an appreciation for old technology. Are purely mechanical clocks more accurate than electronic clocks? No. Are they less expensive than purely mechanical clocks? NO WAY! Mechanical clocks are more expensive. It is about the beauty of the technology inside AND outside.