Tuesday, December 15, 2009

The KI6SN 'Old Man' Mast - Bending all the rules






The January 2010 edition of WorldRadio Online's Trail-Friendly Radio column features the KI6SN "Old Man Mast," an easy-to-carry, lightweight mast that is particularly useful for field operation where antenna supports are few and far between - such as above the treeline on mountain-top excursions.

The antenna derives its name from the Old Man's crooked stature, due to the many PVC joints along its length. The antenna support may suffer from a case of scoliosis, but it's a trusty, solid performer that can get your skywires to where they might not otherwise go.


This illustration above shows the nuts-and-bolts of the "Old Man," even though it's made solely of PVC materials

Several PVC joints connect the short sections of PVC mast material:



The "Old Man" is guyed at two different heights to achieve strength and stability. Here's a shot of the upper guy:





The following three photographs show the method for determining the circumference of the circle that marks where your guying stakes will be placed:













The mast is put up in two phases. Pictured below is what the top of the first phase looks like. The upper portion of the antenna is added to the PVC joint coupling shown here (after the lower portion's guy lines are already staked in place):










For an enlarged view, click on the illustrations.