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11301/11302 in the Bay area

Jerry
 

Hello, Every now and then I post that I'm looking for an 11302 in the SF bay area. I don't need any plug-ins, just a functioning frame. I have one that is defective and I'm unable to figure out the issue. The symptoms are that I get double traces so there is a problem in the triggering or something. All the power is fine. No ripple to speak of. I think at a minimum it needs new NVRAM, assuming it has such. If anyone has one they would like to unload, please send me a note. Or if anyone has the service manual, again, I'd appreciate a copy or a pointer to the same.

Jerry

Jerry
 

ha, for the heck of it, I looked for the service manual again and I found one! A preliminary service manual for the 11301/11302. Go figure.

Clark Foley
 

Jerry, I am glad that you found the Preliminary Service books. Kurt R. was very generous to feed those beasts to the document scanner. Although the books are preliminary, they are not too far from what went to production. These books were prepared for training the service personnel.

I have the film images of the assembled boards known as Kodagraphs. I don't recall if anyone has posted these. These are necessary to locate the components and verify the trace routing/wiring. The image files are huge; so, let me know which board you think you need and I can post it or email it.

By the way, all of the original factory calibration constants are/were stored in flash memory on the 11300 series scopes. If the scope when through a proper servicing, the flash would have been updated to reflect any new hardware or significant calibration change. You should be able to get the thing to show signs of life without the need to cal it from scratch.

Oz-in-DFW
 

Where did you find it? I have a sick one needing attention.

Siggi
 

On Wed, Feb 12, 2020 at 10:21 AM Oz-in-DFW <lists@...> wrote:

Where did you find it? I have a sick one needing attention.



Jerry
 

The manual looks interesting but no real troubleshooting in it. I did see an adjustment for horizontal dynamic jitter or positioning, I can't find it again. The issue with my scope, other than dropping the constants, is that I can adjust the scope display pots to get a nice text display but there is something stored incorrectly because when I reboot, it is all out of focus again. But even when I get a nice text display, the trace doesn't overlay correctly. so the trace looks wide horizontally. I have the software for calibration and went through some of those but it looked, if I remember from last year or so, that it wasn't saving or holding the settings so it probably needs new flash ram.

I wanted a 400Mhz+ analog scope because all my DSOs do a poor job at displaying modulation no matter how much I screw around with them. The other thing I wanted an analog scope for was doing semiconductor curves. I have a couple of circuits (not the octopus type) that do a pretty good job of displaying curves. My DSOs, with the exception of my TDS3054D just don't work well there. I have all the plug-ins and use them in my DSA602 so I would love to get this one working, but I really think it is toast and I am going to take one more look and then trash it.

Thanks

Jerry

John Griessen
 

On 2/12/20 2:09 PM, Jerry wrote:
The other thing I wanted an analog scope for was doing semiconductor curves. I have a couple of circuits (not the octopus type) that do a pretty good job of displaying curves.
So, what speed are you tracing I-V curves, and how different from octopus circuits of old?

Jerry
 

I bought a stationwagon-load of Tektronix and HP specific caps, mostly, but a lot of transistors and preformed resistors from a guy last year or so. He was servicing scopes, I guess. In the box was a curve tracer that's available still on ebay and for the heck of it, I tried it out and it did a fairly decent job on small transistors. You can find it on ebay by searching for "curve tracer" and looking for a bag of parts that cost around $25. I also have a Mini-CT I built that was in QST a while back but this simple current step circuit works pretty well. YAou need an analog scope to use it effectively. The trace is best at 500us per division. The persistence on my 3054B does a decent tds784 and DSA602, 2440, and others won't show a trace. I used my Mini Ct recently to match transistors for a mixer but i could have used this other circuit.

Jerry