[time-nuts] HP 5065 Rb update
ed breya
eb at telight.com
Sat Dec 5 19:14:19 UTC 2020
If the only problem is that you're at the resolution limit of the pot,
you may be able to slightly modify the circuit, reducing the pot's
effect, but also reducing the total adjustment range. I don't recall
what the circuit looks like, but from the discussion I'm guessing it's
like a 10 kilohm or so ten-turn WW with a kilodial on it, and it adds
some adjustable current to the C-field network. The few k ohm range pots
have set-ability that's near the small tick dial resolution. If the pot
is quite low resistance, like less than 2 k, it can be much worse, due
to the larger resistance wire - the wiper can only interpolate so much
between the discrete wire turns, so the net value has more ripple with
rotation. If the pot is in the few k region, you can gain quite a bit of
actual resolution by upping it to say 50 or 100 k, but of course the
rest of the circuit would have to be adapted.
Ed
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