I think I need to clarify what I mean by "backlash". It is not simple free play in the adjustment mechanism- it is something much more irritating, as follows:
I sneak up on the desired result, but manage to overshoot slightly. So I back off on the screw, and find that at first the result continues to change in the *original* direction (making the overshoot even worse) for a bit before finally reversing as I wanted it to. This behavior is not conducive to having a good time making critical adjustments, nor does it lend any confidence in the stability of the adjustment in the face of handling. Dana On Sun, Dec 24, 2017 at 4:06 PM, Charles Steinmetz <csteinm...@yandex.com> wrote: > 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 > > > > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/m > ailman/listinfo/time-nuts > and follow the instructions there. > _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.