Topband: Fish net beacons

[N7DF]

While I was in Guam back in the early 1990s I got to visit with a  ham who was the radio operator on a fish processing ship that spent several days in port there.

He showed me one of the bouys that they used.  It was a cylinder about three feet tall and a foot in diameter,  The bottom part was a battery compartment and the radio was in the top.  There was a screw connection on the top and the antenna was a whip about 8 feet tall that screwed into it.  He said that the transmitter power was usually about 1 watt but could be increased up to 5 watts or so. They had a battery life of about 15 days at low intermittant power. The beacon could be set for continuous transmission, intermittant transmission or triggered transmission.  They are usually attached to the western or southern end of the drift nets, depending on the direction of the currents.  Their frequency can be set between 1700 and 1900 KHZ and some of them also have VHF beacons that can be switched on.  Of course this was 20 years ago so I am sure the technology is far advanced today. 

On a sailing trip between Truk Island and Guam KH6AX and I had the opportunity to see one in place.  We ran across a line of bouys on the second day out and followed it sowthwest for about a mile until we saw the beacon bouy.  It was not transmitting but it looked just like the one I was shown in Guam.

The signals are a really good way to check propagation but usually only to areas where no one lives.