Re: tekcats software for an 11301

Jerry
 

Here's where I am after getting the software running:

Scopes perceived issue is that the trace is fat. I can't tell if this is a CRT issue, sweep or triggering. I've been thinking it is a CRT problem as at one time I was able to get a pretty decent trace of a 1Mhz signal by varying the main trace brightness as I changed the horizontal timebase. Basically, as I changed the horizontal timebase to a higher time period (e.g. 1 sec is higher than 50us) the trace would get fuzzy as more complete cycles were on the display.


Overall, the character display and registration is decent. It's just the signal trace that is off.


Using the software, I have proceeded to check some functions:


0) Whenever the scope initializes, the display goes blank and I have to reset the brightness with the front panel control. This is why I was thinking the EPROM or the EPROM based constants were hosed.


1) So I backed up the constants and loaded them back in after setting the switches as in the manual. This seemed to work but had no impact on the issue at hand. I was really just testing to see if the EPROM was functioning and if there was a checksum that would have failed, etc.


2) I tried loading the default constant file. Again, no impact on either the signal trace width or the brightness issue after a scope initialization.


3) I tried setting the brightness using the menus. Generally, it presents a dot or trace and asks if it is dim or bright in two levels or O.K. In all cases I can't see the dot, line, etc without spinning the front panel control brighter.


4) I tried some of the autocal and other tests in the software without luck. The enhanced accuracy fails unless I bring the brightness up with one of the controls on the scope logic board.


5) I checked the voltages again on connector P91. Some of these should be down around -1,900V and they are sitting at zero. This is confusing as one of the deep negative voltages should vary from -1,100V to -1,900V depending on the setting of the astig Front Panel control and it is sitting around zero even though the astig control seems to work. Having typed all this I am now wondering of they used a coma for a period and maybe the voltage is -1.9V opposed to -1,900. They are all supposed to be referenced to ground and I tried many of the labeled ground lugs with the same results.


5) One test sets the horizontal registration and width using pots 183 and 183. That test was right on the money which I find interesting given the issue I have with the beam thickness but that does use a stored waveform. Having typed this I am going to store a waveform and see if the issue disappears which will ppoint me to triggering opposed to basic CRT voltages.


Though I have the software running I am not having much luck using it to diagnose the issue. I will keep reading and plugging along as I don't have much money invested in it other than the $12 manual from Artek and the fact I dropped my Surface Pro 3 on the cement floor when I was reading the manual. So I would like to see it run after wasting $1,800 of the Surface.


Thanks for the help. There has to be someone on here that worked on the 11000 series!'


Jerry

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