Swapping CRTs

Hi all,

Well, I was hoping that CRT pinouts were different between tubes 19VLUP22 and
19VJTP22 because that would explain the problem I'm having, but apparently they
are the same. Maybe there is something else I did wrong, so maybe someone here
can catch my mistake...

Anyway, last night I swapped a 19VJTP22 tube into a working G08 chassis.
 Unfortunately, the original G08 had an internal short and went to the garbage,
so I was looking for a cheap solution. Fortunately, I had a parted out WG4600
chassis laying around, so I used that tube for the experiment.

Procedure:

I unsoldered the original socket on the neck board and replaced it with the
WG4600 socket. There is a blue "blob" (cap? resistor?) attached via wire
coming out of the socket where the anode wire attaches to it, and I'm not sure
where the other end of the blue blob goes to (gnd? ??), so I left it unhooked.
 I think at one point I attached it to ground and it did nothing.

Anyway, I then swapped CRTs, but marked the original placement of the
convergence rings, then removed it, swapped yokes, and replaced the rings as
they were. I also swapped degaussing coil and shielding and mounted the tube
on the chassis.

Results:

I fired up the monitor and got a picture. However, the guns were overdriven,
as you could see all the retrace lines. Adjusting gun gains and cutoffs was
unsuccessful. Adjusting brightness was unsuccessful. Adjusting High Voltage
was unsuccessful. Deflection seemed to be working fine.

Also, color was very screwed up. There appeared to be three zones of color:
1/3 red on the right, 1/3 blue in the middle, and 1/3 green on the left. As
lines passed through these zones, they became the color in that zone. Very
strange.

So initially I'd say that this doesn't work so well. I can't explain why it
didn't work, so I thought maybe the socket was off by a pin or something else
was screwy. Maybe the heater voltage is incorrect or something. Any guesses?

Anyway, tonight I'm going to try swapping in an Ampliphone tube and see if I
get better results. Maybe someone out there would be willing to swap me an
Ampliphone tube for a 19VLUP22?

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Mark Jenison E-mail address: jenison@cig.mot.com
Cellular Infrastructure Group Motorola--Arlington Heights, IL
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Received on Wed Sep 8 12:57:08 1999