Test Equipment Anonymous (TEA) group therapy thread

[factory]

For 50Hz operation I have changed the crystal from 120.000 KC to 100 kHz, quite surprized I actually had one, almost all the others in the selection were 120kHz.



The mystery device seems quite uncommon, searching the web I could only find one picture of another.

David

For those who are not familiar, size of those crystals can be misleading.
They are bit bigger than usual Arduino stuff, I think.

It's been a while since I started work on this device, had different health malfunction and spent two weeks in Crewe hospital, humanoid TE was something labelled Dynascope in the A&E department and the annoyingly loud Mindray things going off at 5.30 to 6am, needed the earplugs most nights, now need a rage-room filled with old Braun IV pumps (the alarm noise they make was pissing a few of us off). Also noticed Samsung & Philips both using Canon Xray parts.

Anyway back to the uncommon Keithley, the crystal is indeed a bit larger in size to modern ones.





Before the hospital stay I had powered it up with the lamp limiter and determined one of the Mallory capacitors was open, both by measuring AC ripple & using the Peak ESR, today I got round to replacing it and the other plastic cased Mallory caps & another from Richey Electronics (none of these tested bad).
I'm not happy with the condition of the 15uF 300V Mallory cap for the display supply, but haven't got anything suitable in stock ATM. Need some dry weather to deal with the foam dust that is showing in the picture, after changing the caps.

I now have a dead tree edition of the manual, serial no. of the one in the manual picture is one less than my ex-demo one. 



David

[TERRA Operative]

Well, at least you know that manual is as applicable to your instrument as you can get!