Hi All,  Just in case my posting about the '3-finger technique' was
misunderstood, let me clarify one thing.  (I should have made this
point more clear in my initial posting.)

As when tuning any string, the tuning hammer is on the tuning pin and
varying amounts of pressure are being applied to the handle -- either
positive or negative -- to bring the string into tune.  However, once
the optimum point is reached, then the key is struck with a very sharp
blow.

In truth, this technique does not "set the pin".  What is does is help
to equalize the tensions all along the full length of the string.  If
by chance the pitch of the string does change, then pressure is once
again applied to the hammer to 'set the pin' in a different position.

(I am purposely not addressing 'how' a tuner applies pressure to the
tuning pin because there are numerous 'hammer techniques' and that
topic is not what started this thread.  See MMDigest 120229.)

Musically,
John A Tuttle
Player-Care.com
Brick, New Jersey, USA