[aprssig] What a diffeence an antenna makes

Scott Miller scott at opentrac.org
Mon Oct 31 13:15:23 CST 2005

> A 1/4 wave whip over a suitable ground-plane is a reasonable
> compromise.

Does the Pacific Ocean count as a ground plane?  In marine installations, is 
electrical ground connected to the hull?

What I'm thinking of would be a simple, cheap buoy that I can chuck 
overboard while we're en route to San Clemente sometime.  I like Bob's 
suggestion of 4" PVC, and I've already used that successfully for a scuba 
geocache.  Might see if I can put an 8" cap on top, though, and mount some 
solar panels on it.  Even if that doesn't work out, alkaline batteries could 
easily keep it going for months.

A whip antenna would definitely be easiest.  Does anyone know what legal 
requirements there might be for free-floating buoys?  Like does it need a 
flag or other markings?

Just to have it do something useful, I'll probably string a bunch of DS18S20 
temperature sensors on a 1-wire bus with a fishing weight on the bottom. 
I'm open to suggestions on what cable to use.  Sensors could probably go in 
adhesive-filled heat-shrink tubing inline with the cable.

Scott, N1VG

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