Tek 2235 CRT shot or fixable??

[Kidon]

Hi,

I have this Tek 2235 that I got not too long ago,  I decided to start using and went thru most of the essential calibration procedures(including all the CRT and power supply ones, minus the tube voltage (I do have a voltmeter that can handle up to 32kV, but not the optional HT probe).

Anyhow, this is when I noticed this pb. The trace is thinner on the right hand side, and although it is straight when on the middle horizontal graticule line, the right side leans downwards when all the way up, and upwards when all the way down.
Maybe it doesn’t show all that well in the pictures, but it’s clearly visible in person.

So my question is:  Is there a adjustment that can be made to rectify this, or is it shot and I need a new one?

Thanks for your ideas.

[helius]

The pictures of the traces look perfectly normal.
You should consider that any slight geometric issues at the extremes of the display are totally irrelevant for the intended purpose. If the trace is bright and the brightness control directly changes the brightness, the tube is fine. The sign of a bad (gassy) tube is when the brightness control doesn't affect the brightness of the trace, or makes it suddenly very fuzzy. None of your images show that at all.

[james_s]

Yeah I'm looking at those pictures trying to see what the problem is, it looks totally normal to me. CRTs are analog devices, even very good ones never had *quite* the perfect geometry that you get on LCDs.

[Gyro]

If you're really concerned, there's a trace geometry adjustment pot (R870) with adjustment procedure in section 5-5 of the adjustment section of the service manual. This adjustment is for trace straightness in the upper and lower portions of the screen. Note that it is a best compromise adjustment, so may already be set correctly.

[David Hess]

That looks normal to me and within the specifications for geometry distortion.  If it was damaged, I would expect it to be much much worse.