I've made some corrections to my PRC-10 pages.
          Contrary to populate belief the Long antenna mount does not contain a  secret hidden switch which is activated  when when you screw in the base of the long antenna.   Such as on the PRC-25 and 77.

           The matching to the long antenna on the PRC-10 is all done by PFM. 
Antenna matching theory and details can be found at:
http://k4che.com/PRC-10/PRC-10.htm#ant

The beginning of the PRC-10 series can be found here
http://k4che.com/PRC-10/PRC-10.htm

K4CHE