CYP22 in a CTC16?

[Jon1967us]

I happen to have a CYP22 that I acquired from a local "upcycler". Wondering if it's possible to drop in my CTC16 someday, if I need to. It looks like the reverse is possible without much fuss, but I'm not so sure about this way. Will the CY be able to deal with all the different voltages, especially the much higher ones on the G2s?

[reeferman]

An interesting project? Yes.
Pursue the project and let us know how it turns out.

[Eric H]

The CYP has no bonded safety glass and was intended to go in early sets with a separate safety glass for implosion protection.

[Electronic M]

Originally Posted by Eric H

The CYP has no bonded safety glass and was intended to go in early sets with a separate safety glass for implosion protection.

As I understand it the envelope is identical to later tubes except for the lack of a safety glass. If you have a spare safely glass from a defunct 21FBP22 adding it would probably be sufficient to make it as safe as a 21FBP22.

There's 2 HV connectors on a CYP that are connected through a resistor (the ETF should have schematics for CTC-7 through 10 that will have the value)... You'll need a second connector and resistor to duplicate that.

Phosphor efficiency for each color and phosphor color is different between the CYP and FBP so grayscale settings and color rendition may be slightly different from the factory tube...

Not sure if I would keep such a configuration, but I would definitely be interested in trying it if I had the tube and set laying around...if nothing else just to see how it works in practice.

[Yamamaya42]

Originally Posted by Eric H

The CYP has no bonded safety glass and was intended to go in early sets with a separate safety glass for implosion protection.

there really is no reason that it MUST HAVE safety glass, one can be careful and use it w/o it.

it's not like you will be throwing golf balls at it or anything!

for example, I have been using the 21fjp22 without one in the GE CTC-15/16 clone since the safety glass broke when I tried to remove the cataract, and that was well over a year ago.

[Jon1967us]

The thing that concerns me isn't the physical dimension or dual anode, but that the max rating specs are different in a couple places, like G2 600v to the FB/FJ's 1000v. The CTC16 would subject those G2s to 2-300v over max rating, right?

Also, heater current rating on the CY is 1.6A vs 1.8 on the FJ/FB.

https://frank.pocnet.net/sheets/168/2/21CYP22.pdf


CTC10







CTC16x

[Electronic M]

The heater current is inconsequential in a parallel heater set. It would matter in a series heater set, but I don't know of any series heater roundys off the top of my head.

It should probably survive the increased G2. G2 is used to set the cutoff point of each gun, and most setup procedures including the CTC16 will have you set brightness and G2s to minimum, flip the service switch, then turn up red for minimum that gives faint horizontal line, then turn up green to get yellow, then blue to get white...In a strong tube that setting should be below 600V anyway.

If G2 adjustment is set sky high the gun will be turned on HARD, the HV will sag and focus will be terrible...I have a Setchell Carlson rectangular color monitor that had this strange HV and focus problem till I figured out some dope set the G2 controls to max...As soon as I set them up right (minimum necessary advancement) the set was suddenly working like new... I'm kinda amazed the gun stood up to that rejuvenation level emission.

[Tom9589]

I've often wondered why the 21CYP22 had the two HV connections and a resistor in between. Are each of the HV connectors connected to a separate internal Aquadag coating inside of the CRT, thus creating two capacitors. Add the resistor in between and you have a pi filter network. Is that the case?

[julianburke]

The two anode buttons are bridged with a 56K ohm 2 watt carbon resistor with a spring that is used to pull the resistor tight into the buttons.

[doogie812]

Originally Posted by Tom9589

I've often wondered why the 21CYP22 had the two HV connections and a resistor in between. Are each of the HV connectors connected to a separate internal Aquadag coating inside of the CRT, thus creating two capacitors. Add the resistor in between and you have a pi filter network. Is that the case?

They did not want arcing between anode and the G2 grid. I don't know this but I would bet there is not a internal red dope on the neck of the CYP.