[time-nuts] HP 5065 Rb update

[ed breya]

Paul, if the pot is 1 k, set up as a DC divider from a low-Z reference 
voltage, and only lightly loaded by an amplifier circuit, you could try 
upping it to a 2 k or 5 k, possibly 10 k, and get an immediate 
resolution/set-ability boost, with little effect on the rest, and no 
other part changes (except for whatever you need to get that nominal 
C-field current in the right range - a separate issue).

An easy way to assess the pot capability in-circuit, is to put a high 
resolution (5 or 6 digits) DVM on the wiper or amplifier output, and 
just pick some values of voltage, and see how closely you can tweak it 
to any particular value. You can also observe the discreteness of the 
steps, the lash, and maybe some interpolation ripple (non-monotonic 
behavior), by very slowly rotating it while watching the DVM values. 
This will of course also show if there are any bad spots on the pot, due 
to wear, corrosion, dirt, deteriorated grease, etc.

Ed