In article , Maule Driver
wrote:

I don't.

You should.

From the AIM:

4-1-19. Transponder Operation
a. General
3. Civil and military transponders should be adjusted to the "on" or
normal operating position as late as practicable prior to takeoff and
to "off" or "standby" as soon as practicable after completing landing
roll, unless the change to "standby" has been accomplished previously
at the request of ATC.

--
Garner R. Miller
ATP/CFII/MEI
Clifton Park, NY =USA=