Re: Tektronix 7D13 and 7A42 wanted


Harvey White
 

On 11/17/2020 8:29 PM, Ed Breya via groups.io wrote:
Harvey, it's not a logic analyzer except in a rudimentary sense. It's a scope, so you can see what the analog waveform that represents a digital signal actually looks like in time domain. Of course, you sometimes need this when the digital doesn't quite work as expected. I haven't needed it yet, even though I've built a lot of ECL stuff since, that worked just fine. I picture it being useful more in the design of interfacing in ECL/RF circuits, rather than logic fault diagnosis. It's nice to have, just in case.
It's a plugin with "logical" triggering, and variable thresholds.  Then four channels.  Yep, not a logic analyzer, I use one of those whenever I need to look at a reasonably complex digital stream.  Sadly, most logic analyzers of that era don't do well at decoding serial streams.

Let alone a tektronix plugin.



Speaking of which, I just finished battery removal and cleanup. The electrolyte had traveled quite a way, and gotten through to the other side of the board. It's ugly in the affected areas from Cu-blue and corrosion textures on parts and runs, but does not appear to have rotted anything open or shorted. It's drying now and will be fired up shortly. My main worry is that since this looks to be a four-layer board, some vias to the inner layers could rot out - difficult to locate and fix. The electrolyte clearly managed to leak right through some of them.
Not sure about that.  It varies per board and damage, of course. Mine worked well enough with about 15 jumpers, and led me to the relay problems in the front end.  Haven't fixed that yet.

Harvey


Ed




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