Miroslav Pokorni wrote:
Hello Ashton,
My limited experience with bad electrolytics in Tek scopes was that there is
no capacitance. I would guess, the problem was discontinuity rather then
drying out, because failure has been sudden, every time.
In view of that, I wander how much help would be an ESR meter. However, I am
looking into building one myself and would be interested to see what method
you are using. Let me know, please, and if you have the schematic in a
convenient form to e mail, please do so. A rough sketch showing only the
principle is good enough, too.
Regards
Miroslav Pokorni
Your point noted.. as I haven't gotten around to using the meter - can't
say how many caps are marginal. There's a good discussion of the
subtleties in following links, incl. limits of mere ohms or capacitance
'checks':
ESR meter info:
Some more comments about usage:
I ordered from Vancouver BC:
A different (analog) meter - w/schematic refs
As to the Dick Smith kit - I concluded it was cheaper and a lot handier
to not reinvent the wheel. Good qual. parts and it worked precisely as
described. Anyone with Heathkit experience would achieve same, of
course. I haven't tried the hints re small batteries - mentioned in a
link below, but it might be useful on odd PS problems in micro-sized
devices (hearing aids?)
My problem is making the time to troubleshoot a variety of Teks (incl. a
few 485s and one 'chirping'!) - whereas I spent my time mostly using
scopes.. not in their more subtle repair. Some of the arcane problems
which say, the Z-axis board can cause.. stress my more Boolean effforts
:( And if a 335 is clockmaking - a 2xx is watchmaking!
See what you think of the Dick Smith Special. IIRC schematic is on one
or more of these sites.
Cheers,
Ashton Brown
(ex-LBL - particle accelerators. Tons of Tek everywhere!)
