View Full Version : 8KP4 a substitute for an 8DP4?


SwizzyMan
06-01-2015, 05:28 PM
Hello everyone!

I have a RCA "The Personal" (8-pt-7032T) set and it has a weak 8DP4 Picture tube. I recently acquired an 8KP4 aluminized tube that tests brand new and I was wondering if it would be a good substitute for the 8DP4. Aside from the extra pin for the focusing electrode it seems like it would work... Anyone have any idea if this would work?

dieseljeep
06-01-2015, 10:11 PM
Hello everyone!

I have a RCA "The Personal" (8-pt-7032T) set and it has a weak 8DP4 Picture tube. I recently acquired an 8KP4 aluminized tube that tests brand new and I was wondering if it would be a good substitute for the 8DP4. Aside from the extra pin for the focusing electrode it seems like it would work... Anyone have any idea if this would work?

Just being curious about the subsitution. I don't see a 8KP4 in my RCA or GE tube manual. Is there a manufacturers name on the CRT. If removed from a scrap set, what make of set is it? How did you test it? Just wondering. :scratch2:

baursam
06-01-2015, 11:22 PM
http://tubedata.milbert.com/sheets/168/8/8KP4.pdf
http://tubedata.milbert.com/system.html

Doesn't show the description for it as CRT, rather tP , triode and power-penthode.

8DP4 specs, http://tubedata.milbert.com/sheets/168/8/8DP4.pdf


I have no idea but thought this might help.

Eric H
06-02-2015, 12:59 AM
Wow, the 8KP4 can handle 18,000 volts on the anode, was this a tube for a projection set?

The deflection angles seem all wrong, the voltages seem quite different also.

8DP4's aren't all that hard to come by, either from a junk set or sometimes they pop up on eBay.

If the set is working you could just plug the tube in and see what happens, I'm guessing it won't require the Ion trap since it's Aluminized.

dieseljeep
06-02-2015, 08:35 AM
Wow, the 8KP4 can handle 18,000 volts on the anode, was this a tube for a projection set?

The deflection angles seem all wrong, the voltages seem quite different also.

8DP4's aren't all that hard to come by, either from a junk set or sometimes they pop up on eBay.

If the set is working you could just plug the tube in and see what happens, I'm guessing it won't require the Ion trap since it's Aluminized.

If it was up to me, I'd try it. You might have to jumper pin 6 to 10 for a focus source.

jr_tech
06-02-2015, 03:02 PM
Agree! give it a try... The extra length might be a problem, and the brightness *might* be lower than expected... the 2-3kV lost penetrating the aluminum coating might outweigh the reflectivity benefits of the coating at the low accelerating voltage of the RCA 8PT series.

jr