GE wrote:
I recently purchased a 1973 Cherokee Charger. So far, I am really enjoying
the aircraft, but I have a question that has gone unanswered. There is no
mention of it in the POH or the information manual that I have.

Beneath the throttle quadrant but above the fuel selector (on the right
side), there is a knob that I am unsure about. This knob rotates and turns a
marker that indicates "L" or "R". I believe that this may be a trim for the
vertical stabilizer but I am unsure of how and when to use it.

I could be totally wrong, so any advice on this would be greatly
appreciated.

I've never flown a '73 Charger, but I'm a little confused by your description.
The PA28s I've flown have the fuel selector on the side wall by my left knee,
not near the throttle quadrant. But OK, your fuel selector must be in the floor
in the center under the throttle quadrant.

It sounds like you are describing rudder trim. It should be several turns from
the stop in one direction to the stop in the other direction. Turn it to the
right during takeoff and climb to relieve the rudder pressure otherwise required
to keep the ball centered. At level off and beginning of cruise, turn it to the
left to center the ball with your feet on the floor.

The rudder pressure required isn't that great in a Cherokee anyway, so if you
don't want to fool with it, just adjust it for cruise and use right rudder as
required during climb.

Dave