WMG1431 (U3100) Tube Pinout

[Kevin Mullins]

Can anyone confirm if the tube pinout for a WGM1431 (U3100) tube #M34EDC13X is the same as any CR-23 pinout?

I'm doing a tube swap on my little test bench monitor (because I broke the neck) and realized I believe the neckboard pinout is different.
The original is a G07-FBO tube, which is apparently a different pinout from a standard G07-CBO. The original tube # 370ESB22 appears to be a CR-28 pinout.

EDIT:
The heater physical pinout seems to be the same as a CR-23, but the number doesn't match the schematic.
Added a snippet of the U3100 schematic, it's just the numbering doesn't make sense to me.
Sucks too because I have a complete U3100 in my Infinity, but the neckboard isn't marked. 

[Kevin Mullins]

Ok  .... where's Ken when I need him.   

Digging through schematics to find find something that matched what I may have laying around in order to double check this stuff..... I noticed that one of the neckboard options for a K7000 matched the U3100 schematic...... the P456 neckboard.
So If I can verify the pinout of a P456 neckboard I should be good to go.

I attached a snippet of the K7000 manual for a good comparison.
The one on the LEFT is what I need to double check.....the one on the RIGHT is what I'm used to seeing.
The numbering going around the common neckboard goes 4, 5, 6, 7, 8, 9, 10, 11, 12
So this is why the numbering on the U3100 and P456 schematics are throwing me off, they show the blue gun as #3. (?) So of course I wonder if the other numbers correspond differently as well.

EDIT:
Just found the pinout for a P456 neckboard..... so now to do some comparison.

[SirPeale]

If it helps, all the M34E tubes I have in my docs take a type 23 adapter.

[Kevin Mullins]

Yes it does...... I knew the heater pins were right for a CR23, but none of the crt docs I browsed through listed this particular M34 tube, so I'm just trying to double check everything that I can. (as I scratch my head a lot)

I've even broken out the magnifying glass and flashlight to see into the tubes enough to trace things. 

There's still a few pins I need to double check though and compare to a CR23 layout.

[Kevin Mullins]

Well, according to this http://catalog.rell.com/rellecom/Images/Objects/6500/6485.PDF
 ALL M34EDC Series tubes are indeed a CR23 pinout.

So I'll give that a shot and see where it gets me.
Adapter making here I come!! (or something like that)

[qrz]

the neck size is the give away .
 the narrow neck (22.5 mm ) has a diff pin out than a standard 29mm  19/20 " crt


on sencore's cr70 , it is skt 13 for narrow and either 3 or 5 for standard ( don't recall at present    )

qrz

[Kevin Mullins]

Ah haaaa ........ but this tube has the 29mm neck.... on a 14" tube. 

And the original 14" tube has a totally different pinout, even though it is also a 29mm.

 

[qrz]

diff mfgr's and/or model year...  ain't it fun ??

[SirPeale]

It might be a type "24" adapter type.  IIRC I found a 19" tube a few years back that had a neck that would fit my K4600, but it was wrong.  Turns out that some of the colors were in different spots.  IIRC that was the only difference though.

[Kevin Mullins]

diff mfgr's and/or model year...  ain't it fun ??

Yes indeed. But it's gonna be a good learning experience one way or another.
This started off as just a little test bench monitor, burned in, needed capped, the usual.
I just used it to check boards and such to see if they worked, etc.....nothing special.
Well, I need to swipe the yoke from it so I could work on a 19" G07 (same yoke), but lo and behold I swear they put the "glue" on and then put the neckboard on. Not just your typical silicon, this thing was NOT budging off. Needless to say as gentle as I tried I ended up breaking the neck clean off around the pins. So I have a pile of otherwise useless stuff laying around anyways...... let's grab a tube and see what we can do. And that's where this all started.

The CR23 pinout seems to be correct so far. I've made good progress on adapting this tube. Luckily the neckboard on it has fewer components than most and I was able to pull some jumpers and re-route most of it pretty easily. Only had to cut two traces and there's nothing that wouldn't take but 15-20 minutes to put it all back to original.
Of course I have convergence issues and such, but not terrible actually. First thing I had to figure out was that I needed to back the yoke way off the back of the tube to get rid of this fish-eye kaleidoscope effect I had going on. (not a degaussing issue)

One issue I'm having now is the FOCUS is turned all the way down one direction and it still needs more. Not horrible but noticeable.

The biggest issue I'm having is the SCREEN voltage...... I have to turn it waaay down also and it's super sensative.

This chassis needed capped before I started this whole process, so I may do that before I go much further just to have it done and off my mind.

[Kevin Mullins]

One issue I'm having now is the FOCUS is turned all the way down one direction and it still needs more. Not horrible but noticeable.

The biggest issue I'm having is the SCREEN voltage...... I have to turn it waaay down also and it's super sensative.

This chassis needed capped before I started this whole process, so I may do that before I go much further just to have it done and off my mind.

Went ahead and capped the chassis, helped a little, but nothing to brag about.
The more I let it run I noticed the screen brightness sometimes increasing on it's own and I'd have to "bump" it back down a tad. And occasionally the focus adjustment would cause the screen brightness to flare up a bit.
I think the FOCUS/SCREEN block may have problems/leakage. (it's separate from the flyback, G07 type)
I can wiggle the SCREEN pot and make the screen brightness twitch considerably.

This is all stuff I never noticed on the old tube as I never really adjusted it. It was so washed out looking that I never bothered, especially for what I used it for.

So I may swap that block out just to see what happens then.

[Kevin Mullins]

So I may swap that block out just to see what happens then.

Pulled a block off a G07 I just rebuilt to test with....... it absolutley fixed the FOCUS issue, focused beautifully.

But the SCREEN voltage issue is persistant.
Sometimes I can even turn it down to where the picture is nice, but the next time a bright image comes up the screen kinda "creeps" up in brightness again. Then I have to bump it back down, etc, etc. over and over again.

I'm also getting a lot of "streaking" in one direction.

I'll try to grab some pics, but my camera sucks indoors and definitely doesn't do a monitor any justice.

Don't get me wrong....... this thing actually looks FANTASTIC compared to the old tube.
Much smaller dot pitch, has the dark masking versus the gray looking stuff. Looks pretty sharp considering I didn't know what I was doing.
 

[Kevin Mullins]

Some crap pics, but the one shows the streaking pretty good.
If I turn the SCREEN down enough to rid most of the streaking, and the lines you see in that particular pic, then the rest of the image is just away too dark. No real happy medium. And of course there are no other brightness or contrast adjustments on this chassis.
(was using a 48-1 board for testing purposes)