Color adaptable Admiral goes in 14 hours

[Steve McVoy]

Here is some information on Butterfield:

http://www.earlytelevision.org/butterfield.html

[Steve McVoy]

The color adapter that Admiral planned to build had to be similar to the one CBS made:

http://www.earlytelevision.org/cbs_color_converter.html

Take a look at the schematic to see how simple it was.

The 4 pins on the connector in the Admiral receiver were for vertical sync, video, B+ and ground. The vertical sync was used to drive a phase comparator that controlled the speed of the motor that drove the wheel; the video was used because an extra pulse was transmitted in the red fields, and this pulse was extracted to lock the wheel in the proper phase (otherwise it could lock on any of three phases. The CBS converter and John Folsom's RX-41 receiver -

http://www.earlytelevision.org/field...rototypes.html

- don't have this feature, and you have to manually lock it to the proper color phase)

Our Gray Research monitor does have the feature:

http://www.earlytelevision.org/gray_monitor.html

The other change that was required in the receiver was the horizontal scan rate, which had to be 29,160 Hz, and the vertical scan rate, which had to be 144 Hz for color. The 4 pin connector on the Admiral doesn't provide a way to do this, so it is a mystery to me how this would have worked.

Admiral published a brochure showing their converter

http://www.earlytelevision.org/cbs_c...s.html#admiral

which does appear to change the scan rates, but it couldn't have used the 4 pin connector on their sets.

[Pete Deksnis]

Subject Admiral Model 17K12, Chassis 14E76-2 has been called “early analog vaporware!” for a lack of hard-wiring to its color adapter connector. I've add my current thoughts regarding options for the future of this set to my site. For new stuff added to this link, scroll down to 'The next step...?':

http://home.att.net/~pldexnis/potpou...e_Admiral.html

Comments solicited and gleefully accepted.

[Steve McVoy]

Here is the Popular Electronics article about Butterfield color:

http://www.earlytelevision.org/butterfield.html#pe

[old_tv_nut]

Because of the requirement to run at NTSC field rates, the Butterfield color produced the worst possible flicker rate - 5 Hz. The eye is most sensitive to luminance flicker at about 5 or 6 Hz. Fechner wheels I have seen seem to produce color well at higher rates where the flicker is not so bad, so using this technique with a modified TV system at higher rate might work well.

[andy]

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[Eric H]

This Motorola has an octal socket on the back that may have been for a color adapter.
http://cgi.ebay.com/motorola-tube-TV...QQcmdZViewItem

Some sets should go straight into the dumpster however and this is one of them!

[andy]

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[Pete Deksnis]

(1) My direction with the Admiral is to convert it to receive 1951 CBS Color broadcasts in monochrome. However the CA 100 color adapter it was originally to be used with was probably the Admiral equivalent of the CBS adapter Steve McVoy is now restoring. And so the set was probably never meant to be altered for b&w reception of CBS Color. Therefore, I ask, is there any historic value to such a conversion?

Sure why not. My justification for the effort is to mimic people who in 1951 would have converted their NTSC sets to receive CBS Color in b&w. Who knows if it was ever done? Why not do it now. Gernsback and others would have quickly published such stuff...

I suspect the set will need a new output transformer if, according to vintage documentation, a 'correct' conversion is to be made. Fortunately, specifications for the 2-tap transformer are included in the CBS documentation. Maybe one can be made. Also, waiting to see how Steve McVoy's modification to the fly in a 9T246 he's adapting to CBS Color turns out. Am following that work here:

http://www.earlytelevision.org/cbs_c...storation.html

(2) Also, there's a vintage Admiral tuner question maybe someone can answer. Fine tuning is a function of the position of that spiral cam on the tuning knob in the photo. There's a wire from the LO to the vicinity of the cam, but I don't see how the Xc is varied by that plastic cam. Clearly there is because it works. What am I missing? There doesn't appear to be anything printed on the other side of the cam.

[John Folsom]

The plastic cam is the dielectric in the capacitor formed by the wire and post coming from the LO. As the amount of plastic (or phenolic) in between the post and chassis ground varies, the amount of capacitance to ground varies. It only takes a handfull of picofarads to do the job.

[Pete Deksnis]

Thanks John. No wonder it looked like all dielectric. Guess I haven’t been around long enough!

[polaraman]

BINGO! I have a complete 17K chassis and the color socket is fully wired. The socket had this really strange male socket in it. It was hell to get the darn thing out. I would be willing to donate the chassis minus the CRT to the cause. I need the CRT for another RCA project. I just got back from getting it. It was in my storage area in Georgia. I drove 700 miles today(round trip) and am beat. I will post more pictures tomorrow.


polaraman

[Pete Deksnis]

Your chassis would be the better choice for this project. I have a good CRT.

700 miles! Sounds like our yearly sprint to the ETF convention.

[polaraman]

I got this Hallicrafters Tv today. It is a color compatible set also. i can't get it off the truck at the moment. I will look later to see if the socket is wired.

polaraman

[bgadow]

This all prompted me to pull down my Admiral 17K22. It needed a new focus control installed anyway. Mine is stamped with the color adaptor information but lacks the socket; there is a piece of cardboard attached over the hole. Maybe this was after they gave up on the idea? It was built in '51 but I'd have to go look to see the exact date.