Tube Swap Question

daskrabs

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I have a K7000 (Zenith tube) witha weak blue gun and some burn-in. I also have a Pentranic CH-288 (Licus tube) with sync issues, but the tube is new. I'd like to swap tubes. The K7000 has a 9-pin neck, and the Pentranic has a 10-pin neck, but they appear to have the same harness (CR-23?). Can I safely swap the tubes to use the K7000 chassis on the Pentranic tube?
 
If the tube has a different pinout than the other, then no. Easy test is, try plugging the neck board into the donor tube.. If it fits, then do a full swap.. Yoke, rings, etc.. If the pins don't fit the neck pcb, then you have your answer man.
 
So I did the swap. It worked (at first). On power up, the picture was flipped and backwards. I think this is just from having the yoke wires in the wrong order for this tube. Should just be able to swap them.

However, I had the monitor on for 5 minutes, then it suddenly shut down, and I blew a fuse. I need to order some more fuses before I can resume testing, but in the mean time, is there anything I should check? Or do I have to wait for the fuses to arrive?

I know this tube swap was ill-advised, but I just had to try it.
 
What are the ACTUAL tube numbers on those two tubes?
I'm not getting how a 9 pin neckboard worked on a 10 pin tube.
(knowing the tube numbers would clarify this)
Typically they are either the same or it doesn't work.

Which fuse did you blow?
Did you swap the K7000 yoke over as well?

And yes, a flipped and backwards picture just means you need to flip both the vertical and horizontal yoke connections. Just DO NOT mixed them up between horizontal and vertical.
 
F1 is the fuse i believe (2A 250V).

I didn't swap the yoke as well. Should I have? (Edit: I guess so)

Licus (new): A63LIC36X58

Zenith (old): G-A63ADG25X / 04RCO105-005
 
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Should have swapped the yoke...tube would probably be fine but the new yoke has less ohms/impedance and therefore loaded down the deflection circuits more. Although the numbers were really close, in this case going from 1.5 ohms to .8 ohms is practically reducing the ohms by half (in theory doubling the load).

Check the horizontal output transistor and see if its shorted, and/or look for other toasty components.

Although the numbers were really close, in this case going from 1.5 ohms to .8 ohms is practically reducing the ohms by half (in theory doubling the load).

As long as the CR sockets match from tube to tube chances are they'll work (they must have the same pinout to be the same socket), but the yokes are usually the deciding factor. Tube swapping is not an exact science unless you have a number-for-number match.

For those reading, this is a 25" K7000 (A63=25" tube)
 
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