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  #106  
Old 04-12-2018, 12:27 PM
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Little late to the party. But congratulations on acquiring that rare Admiral Regent model. Here's an ad featuring your set. Should look good on the wall behind your color tv.

-Steve D.
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File Type: jpg 1956 Admiral color #2 (1).jpg (103.4 KB, 53 views)
File Type: jpg 1956 Admiral color (1).jpg (109.1 KB, 56 views)
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Last edited by Steve D.; 04-12-2018 at 01:11 PM.
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  #107  
Old 04-12-2018, 01:27 PM
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Alright then ceramics it is then. And thanks Steve! I'll make sure to frame those when I finish this up.
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  #108  
Old 04-12-2018, 10:35 PM
mrjukebox160 mrjukebox160 is offline
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I wonder why the red screen has a lower voltage range than the other 2?
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  #109  
Old 04-13-2018, 04:36 AM
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Quote:
Originally Posted by mrjukebox160 View Post
I wonder why the red screen has a lower voltage range than the other 2?
The red phosphor is the least efficient of the three phosphors. In order to produce balanced white, the red gun must supply 47 to 67 percent of the total anode current, whereas blue is 11 to 24 percent, and green is 20 to 33 percent.

This is why with the early color CRTs that are under vacuum but weak (say a 15GP22, 19VP22, 21AXP22, or 21CYP2), it is more often than not the red gun that is toast with the blue testing fine, and the green somewhere in-between.
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  #110  
Old 04-13-2018, 02:58 PM
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I wonder how many of those sets were sold. Most TV stations and networks, except NBC, weren't broadcasting much color programming in 1956; many if not most local TV stations were not even set up for color telecasting then. Cincinnati's NBC affiliate, WLWT channel 5, was a pioneer in local color telecasting, being one of very few stations at the time to have the capability to broadcast color film, videotape, network and local programming. The only other TV stations to have such full color capability at the time were probably the network O & O (owned and operated) stations in (at the time) New York, Chicago and Los Angeles. The rest broadcast network color shows in b&w, converting to color as their finances permitted; some stations in smaller cities may not have done so, again for financial reasons, until the 1960s or even the '70s. The networks all had color presentation logos (NBC's peacock, ABC's lower-case "abc" in the middle of a large black dot, and CBS' animated logo in which the letters "CBS" dropped into place on viewers' screens, with the network's "eye" logo appearing at the very far right of the screen, and an announcer proclaiming "CBS presents this program in color"), but most folks saw these in b&w.

I am sure color TV sets were out of reach of most folks in the 1950s because of the $500 price tag at the time. I think most folks who had a TV at all in those days were watching black and white, not getting color until years or decades later (see my comments above). The only time many of these folks ever saw color TV was at a friend's or neighbor's home, and then only for extra-special programs. Add to this the extra cost (and frequency) of service calls on color sets (much more often than b&w) in the 1950s, and it isn't difficult to imagine why color TV did not become popular (i. e. did not "take off") until the 1960s-'70s. NBC may have been the first US television network to broadcast 100-percent color programming, starting in 1966, but I am sure, as I said, most folks didn't see many of those programs in color, on their own sets, for years or decades after that because of the sheer cost of color TV receivers at the time.
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  #111  
Old 04-13-2018, 04:05 PM
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Me curios: what made early color sets so unrelaible? (black and white ones could work for years with no problem).
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  #112  
Old 04-13-2018, 08:23 PM
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Originally Posted by Telecolor 3007 View Post
Me curios: what made early color sets so unrelaible? (black and white ones could work for years with no problem).
In color television's early days, the technology was brand new and had a lot of bugs that had to be worked out, as with all new technologies; yes, even flat screen HDTVs when they first appeared on the American TV market. The first flat screens were also very expensive and had bugs, not the least of which was a phenomenon called "image burn-in" in which an image could and all too often would permanently burn itself onto the screen; this ususally occurred if a stationary image was left on the screen for an extended period of time. It was for this reason owners of plasma flat screens, now obsolete, were warned not to view stationary pictures or images, such as network or TV station logos, for any length of time, otherwise the image would burn itself into the screen, ruining said screen. Such damage would not be covered by the manufacturer's warranty.

Color television sets are also much more complicated than b&w sets, which meant the early ones, especially, had more to go wrong with them. Another problem with early color sets was that the set could not be moved from one location to another, even in the same room, without the CRT becoming magnetized; this meant having to "degauss" the tube every time the set was moved any distance, using a degaussing coil. Black and white (monochrome) television CRTs did not require degaussing, since they had no shadow mask to become magnetized. B&W tubes did, however, have a device called an "ion trap", a magnet which fit around the neck of the CRT. As its name implies, the ion trap traps negative ions and prevents them from burning the CRT screen, which of course would ruin the tube immediately. The ion trap must be adjusted for maximum brightness, usually only after the CRT is replaced.

Later color sets (and all sets up to the end of the NTSC era) had automatic degaussing systems, with the coil mounted permanently to the bell of the CRT; the coil was activated by a thermistor. These auto-degausser systems degaussed the tube every time the TV was turned on. This auto-degaussing system made it possible to move a color set from one room to another (or anywhere, for that matter), without having to worry about the CRT's shadow mask becoming magnetized. A magnetized shadow mask would cause purity distortion and other problems that would degrade the picture. This would not harm the CRT or the television itself, but it would cause ugly color blotches on the screen, most noticeable on b&w programs, although these blotches will also be seen on a solid color raster (usually red) which is normally used for purity adjustments.
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Last edited by Jeffhs; 04-13-2018 at 08:32 PM.
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  #113  
Old 04-13-2018, 09:36 PM
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Quote:
Originally Posted by Telecolor 3007 View Post
Me curios: what made early color sets so unrelaible? (black and white ones could work for years with no problem).
A few things. First, most color sets made before 1960, the earlier the more this is true, had paper capacitors in them while post1960 sets used more film based caps. Monochrome sets before film caps were about as bad as color sets were. Earlier models tended to be overcomplicated and the more parts with fixed failure probability the higher the probability of the device failing as a whole.
Many color sets into the mid 60's were RCA based and RCA used circuit boards. Boards are not the best thing to put tubes on and tend to fail from heat.

When Zenith entered the game it was not uncommon for their sets to last a solid decade maybe with some work. GE potracolors somehow use fewer parts than some monochrome sets of their day and tend to last longer than those sets as well...Ultimately in a really good design (there were many mediocre/bad ones) the more parts in the set the sooner it dies...Color had more parts on average.
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  #114  
Old 08-16-2018, 08:14 PM
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Got tired of seeing this collect dust on the bench so I'm back at it. Halfway through the recapping procedure and decided to do a mid course status check. I noticed the tuner has no effect on the picture and is completely dead. So I had to inject a composite signal to G1 of the video output. The video circuit is new to me atleast. There is not a video amp tube before the output tube. I'm guessing the 4 stage IF eliminates the need for one? Considering most of the newer production sets (CTC 5, 7, 10 etc) use a 3 stage IF instead of 4 and add a video amp tube. This setup threw me off guard when I went to inject a composite signal, I didnt think it would work since the output is past the delay line and the signal would effectively not even pass through the delay line so the chromanince and luma signals would be all out of wack. I was able to get a picture which is pretty incoherent, but it does show signs of life! I still am wondering if composite video can be effectively injected in this set, I have moy doubts. The carrier video voltage is only 1 volt though so no preamp should be needed.
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File Type: jpg 20180816_203613.jpg (34.6 KB, 49 views)
File Type: jpg 20180815_204605.jpg (72.0 KB, 31 views)
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Last edited by SwizzyMan; 08-16-2018 at 08:23 PM.
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  #115  
Old 08-17-2018, 12:27 AM
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You got me to look at the schematic.

The 4 stage IF doesn't necessarily eliminate the need for a first video amp in terms of video voltage, at least not in terms of luma amplitude. In sets with a first video amp, the first amp is used as a cathode follower for luma to drive the delay line, so there is no voltage gain, just a low impedance output to drive a defined resistance into the delay line. It's hard to know, however, if the final IF output transformer in the Admiral is actually providing a lower impedance than in other maker's designs (supplying more current, not voltage), thereby replacing the impedance matching effect of a cathode follower stage. To answer this speculation, you need to know the turns ratio of the last IF transformer that drives the detector and also calculate how much load the detector and its following circuitry represents.

The luma circuitry in this set also contains some mutually coupled coils that look like video phase correction. Very interesting.
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  #116  
Old 09-02-2018, 05:33 PM
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The IF stage is horribly out of alignment so I'd like to just bypass it and the tuner for now and inject a direct video and audio signal into the set. Of course with the absence of a video amp before the luminance line, I'm not sure where to inject a composite video signal. Anyone here know where I should inject the composite video signal? Here is the schematic http://www.earlytelevision.org/pdf/a...sams_383-1.pdf
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  #117  
Old 09-02-2018, 05:50 PM
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It's hard to trace through where the grid bias of the video amp comes from, but a good thing to try first might be to open the connections to the detectors by disconecting L20 and L28, then tie L20 and L28 together as a video injection point. This should work OK for chroma, as it is capacitively coupled, but you may have to supply some negative grid bias for the video amp (schematic says -.8 v at the grid). But that is after the delay line, so just try coupling video through and see what happens first. Or, measure the DC at the detector output before you modify anything, to get an idea of what's needed.
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  #118  
Old 09-03-2018, 06:57 PM
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Quote:
Originally Posted by old_tv_nut View Post
It's hard to trace through where the grid bias of the video amp comes from, but a good thing to try first might be to open the connections to the detectors by disconecting L20 and L28, then tie L20 and L28 together as a video injection point. This should work OK for chroma, as it is capacitively coupled, but you may have to supply some negative grid bias for the video amp (schematic says -.8 v at the grid). But that is after the delay line, so just try coupling video through and see what happens first. Or, measure the DC at the detector output before you modify anything, to get an idea of what's needed.
Alright ill try that and see what happens. Will eventually align the IF.
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  #119  
Old 09-13-2018, 05:21 PM
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We Have A Picture!

Decided to just align the IF and the difference is night and day. The picture is crystal clear aside from the slight hv interference since my video cable was pretty much touching the hv wire. The sound is crisp and clear and it overall looks SO much better. Now I gotta do some basic setup before I move on to color setup. Make that another living c332!
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File Type: jpg 20180913_175536.jpg (58.8 KB, 42 views)
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  #120  
Old 09-13-2018, 08:21 PM
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