A question about some crt's ( round bw picture tubes)
 

Hello Guys-- I am about to become the owner of some old tv parts. There are several old crt's in the lot. I am curious, if anyone knows if any of these tubes are useful, and if anyone might want any of them.

1- 5fp4 (there are 3 of these, two in boxes. the ("p4) designation would seem to suggest tv use).
2- 5fp7-(looks lke a 5fp4.)
3- 5fp11-?( screen is lighter than a ("p4)
4- 7cp4 ( there are 2 of these)(again, suggest tv use)
5- 10sp4- (looks like a 10bp4.)

There are lots of other good parts, such as flybacks, and yokes. When i get them, I'll take a look at some numbers.

5FP4 - View-Finder CRT

5FP7 - Oscilloscope CRT

5FP11 - Oscilloscope CRT, P11 phosphor for photography

7CP4 - Monitor CRT, electrostatic focus

10SP4 - Monitor CRT, electrostatic focus



Chuck

Re: A question about some crt's ( round bw picture tubes)
 

rca2000,

Yes, you are correct as to the P4 designation in CRT tube type numbers denoting TV tubes. P4 is the phosphor designation and is used to denote monochrome TV CRT phosphors. P22 in the type number (as in 21CYP22, etc.) tells you the tube is a tri-color CRT used in color TVs. Another popular type of CRT phosphor is designated P1; tubes with this type phosphor are found in oscilloscopes and other types of electronic test gear.

Hope this info helps. I've been fiddling with electronics for many years and am an amateur (ham) radio operator (the latter for over 30 years), so I feel I know my way around tube gear fairly well. I like the old tube equipment (especially older Zenith radios, since I moved to an apartment four years ago; they take up a lot less room) because it's nearly impossible to destroy a tube if you goof, whereas with solid state gear, one quick short can damage a string of transistors and/or ICs before you know it (by then, of course, it's too late). I also like tube gear because the chassis are generally more spread out than the newer solid-state stuff, hence less chance of causing accidental shorts.

Good luck and very kind regards,

In case anyone is interested in trivial CRT phosphor info:

P1 - Yellowish-green fluorescence, medium persistance, general oscillograph applications.

P2 - Yellowish-green flurorescence & phosphorescence, medium persistance, long phosphorescence

P4 - White fluorescence, medium-short persistance, B&W television application

P5 - Blue fluorescence, medium-short persistance, photographic applications

P7 - Very long persistance two layer screen, purplish-blue fluorescence, yellowish-green phosphorescence, low-speed application.

P11 - Brilliant blue fluorescence, medium-short persistance, photographic applications

P12 - Yellowish-orange fluorescence & phosphorescence, long persistance, low & medium speed applications

P14 - Long persistance two layer screen, purplish-blue fluorescence, yellowish-orange phosphorescence, low & medium speed applications

P15 - Visible green & invisible near-ultraviolet, short persistance UV, medium persistance green, used in flying-spot scanner CRT

P16 - Violet & near-ultraviolet fluorescence and phosphorescence, very short persistance, flying-spot video signal generator applications

P20 - Medium-short persistance, yellow-green fluorescence, high efficiency

P22 - Medium persistance, three color phosphor, color TV application

P24 - Short persistance, green fluorescence and phosphorescence, used for generating color signals from color transparencies.


Chuck