View Full Version : 21CYP22 vs. 21FJP22

04-18-2015, 02:08 AM
Can you replace a CYP with a FJP ?
what are the differences with these two crts?

04-18-2015, 02:33 AM
Not entirely sure of the difference, phosphors I think and the fjp is a bonded tube. The cyp (that i have) requires a separate safety glass. Yes, they are completely interchangeable though.

04-18-2015, 07:43 AM
Also... the 21CYP22 has two HV plugs.

04-18-2015, 07:55 AM
I've had an FJP in my RCA CTC-10 set since 1977, and it's running just fine.

It came with a CYP.

If I'm not mistaken, RCA used to have some upgrade mods for using the FJP in a CYP design chassis. My set does not have the mods.

Nobody has ever complained about the color on my set.

04-18-2015, 09:33 AM
the anode lead on a FJP "may" be close to the mounting ring (if used). It was only about 1" away so you need a good solid fitting anode plug to keep it from arcing.

04-18-2015, 05:25 PM
When I put an FB into a CTC-7 the support ring was very close to the anode connection, and arced over a bit. I solved the problem by taking two packs of high voltage putty and compressing it between two pieces of a Cool Whip top that I'd cut in half, and carefully wedging it between the ring and the area around the anode connection. Worked perfectly without modifying the mounting hardware. The putty is still available on-line from a few suppliers, including MCM.
Best of luck with your swap. :thmbsp:
p.s. It still might arc even if you are careful to use a "heavy duty" anode connector, whatever that might be... I tried a few different ones with no luck until the "Cool Whip" solution.

04-18-2015, 06:11 PM
IIRC I used one of the modern era anode lead caps (very wide, very pliable), no problems so far. Just need to make sure its stuck down very well so no air can ionize.

04-19-2015, 04:43 PM
Both tubes are completely interchangeable. The FJ does have a bonded face and the CY has two anode buttons that are bridged together with a 56K ohm 2 watt resistor that is held in place with a spring and does NOT have a bonded face. The CY has sort of a orangey looking red.

04-19-2015, 06:34 PM
I forgot about the 2 anode buttons. Been a while since I looked at mine.