What's the Friendship Cruise, you might ask?
|Figure 1: |
On the Green River near-ish "Turk's Head".
Click on the image for a larger version.
Unless you've been in rural, southeast Utah it's hard to appreciate the landscape: The Green and Colorado rivers slice their way through the landscape, spending much of their time at the bottom of 1/4-1/2 mile-deep gorges surrounded by some of the least-inhabited land in the lower 48 states. Just downstream of the confluence of the Green and Colorado rivers is Cataract Canyon, a fearsome set of rapids that has claimed quite a few lives over the years.
In a remote, desolate place and on the where the only direction that one moves without power is downstream toward dangerous rapids it's vitally important that logistics and safety be considered should someone break down or experience an injury. Being in a remote area where telephone coverage is spotty at best at "ground level", such coverage is all but hopeless when you are thousands of feet lower than the surrounding landscape! Even satellite phones don't work too well on many parts of the course owing to the limited view of the sky!
|Figure 2: |
High-efficiency HF loop antenna on a boat. These
antennas have been used for a couple of decades
for communications on 75 meters. They are about
3 feet (1 meter) in diameter.
Click on the image for a larger version.
During the cruise's heyday in the early-mid 1970's there were as many as 700 boats on the river at the same time and careful watch had to be kept on the river to assist boaters in need as well as manage who's boat trailer needed to be delivered to what location to pull it out of the water! Since that time, the numbers have declined, but a few die-hards and adventurous newcomers still descend on Green River at the end of May - when they hold the cruise, that is!
For decades, the mainstay for communications was on the 75 meter amateur band which, during daylight hours, has an effective coverage radius of a few hundred miles. Utah, being by itself among the western states, puts this band largely out of reach of most of the country's population centers with Salt Lake being about the only large city within daytime range. On the boats were mounted mobile rigs with small HF antennas - both loaded verticals and high-Q tuned loops - that provided reliable coverage from anywhere along the course, no matter how deep the canyon. At night, 75 meters "lengthened" covering large chunks of the U.S. and Canada by nightfall and "local" coverage degraded, but by the time it started getting dark almost everyone on the river had made camp or gotten to the end and pulled their boats out so very little traffic handling was generally required.
At several points along the course - one at each end and two places in the middle - were strategically-placed stations, also equipped with HF communications where river access was possible via vehicle allowing fuel trucks to replenish the boats' gas tanks as well as trailers to allow boats to be taken off the river.
75 meter HF worked quite well for the 30 or so years that it was the sole source of communications on the river, only occasionally succumbing to the odd solar flare that caused all signals on the band to "disappear" for a few hours. In the 60's and early 70's, VHF such as 6 and 2 meters was occasionally tried, but its signals had difficulty escaping the deep river gorges and the range was limited to only a few miles up and down the river. By the time the 80's and 90's rolled around there were a few 2 meter repeaters in the general area but their coverage on the river was extremely spotty, again since signals had difficulty escaping the deep, narrow canyons!
In the late 90's, we started to look in earnest at how VHF and UHF might be used in providing coverage of the river, knowing that we faced a significant challenge in finding locations that had any hope of catching the feeble signals emanating from the cracks in the Earth - but that story will have to wait for another day!
Hopefully, the water conditions in 2013 will be favorable for the 50th anniversary of the cruise!
- The official "Friendship Cruise" web site: http://friendshipcruise.com/
This page stolen from ka7oei.blogspot.com