I would recomend using a different ham freq. than 146.52 simplex as most
hams use it for a chit chat freq. and in a large city it would be busy all
the time. When I am out doing stuff like Geocaching I use 147.570 kinda off
the beaten path type.

 PANDA77
 
Patrick Brown
 Check out
http://www.geocaching.com/
http://www.azgeocaching.com/