Gordon, something worth trying might be low-band. About 20 years ago, I lived in an area where hams did course communications for rally events in very mountainous terrain. I remember experimenting one night about 2am with my partner at the other end of a heavily wooded course, about 12 miles end-to-end.
444 MHz simplex, 5 watts, colinear mobile whip - no copy. 146 MHz simplex, 5 watts, 5/8-wave mobile whip - no copy, but would barely break the carrier squelch. 29.6 MHz simplex, 4 watts, FM CB conversion, 1.3m helically-wound mobile whip - full quieting and S9+. Antennas might be a bit of a trick for portables on 10m, and a repeater might have to be crossband, but worth a shot. 73, Paul, AE4KR ----- Original Message ----- From: Gordon Cooper To: Repeater-Builder@yahoogroups.com Sent: Thursday, September 02, 2010 1:51 AM Subject: Re: [Repeater-Builder] Re: Circular polarization for VHF repeaters? Our repeater runs 5 watts output, needs to run three or four days off a gelcell, and most importantly has to fit into a backpack to be carried to a convenient hilltop. Fortunately, the split is 3 MHz so that the duplexer is of a reasonable size. The problem is getting reasonable coverage. Sure the search areas are fairly small but usually encompass several ridges and deep valleys. We use vertical polarisation with a 5/8 whip on the repeater and the search teams have flexible dipoles that fit into their backpacks. Sharp ridges and steep slopes contribute to coverage problems. Would circular polarization help?? I think not.
