Hi David,
It isn't your soldering quality or ability that will degrade
the instrument, it is rather the quality of the parts you
add, or replace, and what you do to fudge things into sort of
working, that will damage/degrade the instrument.
Devices like the 720A are firmly in the category of
I can't replace the bad resistors in the A decade - they are in the oil bath
and the manual says that in this case you sent the unit back to Fluke for a
re-build. These days, I suspect they won't even do re-builds at all (or only
at *silly* money), but make you buy a new one, and may well not
David:
I had the same problem as you when I got my used 720A years ago. Both
the "A" and "B" decade had a few resistors that had changed over the years.
I don't think as bad as you experienced but still they would not balance
within the range of the adjustment pots. So I "adjusted" those
Hi Dave,
The 11ma loading is a threshold where over dissipation will
occur, letting the magic smoke out of the box. The 720A won't
be physically damaged, but will be far from usefully usable
long before that point. No load is the only acceptable loading
of a 720A.
The damage I am referring to
Chuck,
I totally get your point that ideally you should use any KVD in null-balance
mode. I do note however that you can load it up to 11mA without damage though
I've not once gone anywhere near that (worst case insult has been about 0.1mA).
However it does also say that to avoid loading
