[time-nuts] TAPR "PulsePuppy" Pot Selection

[Charles Steinmetz]

John wrote:

> I didn't really notice much backlash, though when setting oscillators I try to approach (slowly) from one direction until it's "good enough" and then stop, to avoid that problem.

The hot tip is not to just "sneak[] up on the sweet spot and then walk[] 
away," as Dana put it.

Anytime you have an adjustment with some hysteresis (classic example is 
setting a d'Arsonville movement to zero), you want to sneak up to the 
perfect setting and then run the adjuster *back* the way you came just a 
touch, to leave the adjusted part on its own without any mechanical 
connection to the adjustor mechanism.  Such contact is almost always the 
culprit if the adjustment drifts after you set it.

This takes some "feel" for the motion of the adjuster mechanism, but it 
is well worth investing the time to learn it by repeated trials of the 
adjuster before you leave it alone.

Dana is spot on with his advice to tap the board (or whatever 
mechanically supports the adjusted part) to make sure it doesn't drift. 
  If it does, you either failed to pull the adjuster out of contact with 
the moving adjusting part, or the adjusted part just can't hold its 
setting.  In either case, better to know that now than after you button 
the instrument back up.

Best regards,

Charles