[TenTec] Fiberglass poles?

[Jim Brown]

Two points.  First, NOWHERE was it stated that a hole should not be 
drilled in the pole.

Second, the website stated that "These are extremely strong poles, with 
a much greater wall thickness (up to 2mm!) than the usual "fishing rod" 
types. A special reinforcing winding technique - several layers of 
fiberglass are wound in alternating direction (criss/cross winding) - 
provides greatly increased lateral and linear strength."

Glen, W6GJB, is a mechanical and aeronautical engineer recently retired 
from the space program, and is an expert in the strength of materials, 
how those materials are formulated, and how they are used. Glen is the 
inventor of the Air Beam Tents used by the VK0EK DXpedition. They are 
rapid deployment tents, and were designed for use by the military. 
Another area of Glen's expertise is parachutes -- he's one of the guys 
who knows how to catch stuff returning from space.  Glen carefully 
studied the pole after it broke and found that it was NOT constructed as 
described above, that there were not "criss/cross windings." If there 
had been, the pole would not have broken because the hole would not have 
weakened it. He measured the pole thickness as 1.75 mm.

As to the poles on DXpeditions -- within the last year, I attended a 
presentation by a major DXpedition who had used these poles, and saw 
photographs that clearly showed that the poles had broken in the wind.

73, Jim K9YC

On Sun,11/6/2016 1:06 AM, rick at dj0ip.de wrote:
> Jim broke the cardinal rule when he erected the antenna:
> He drilled a hole near the bottom of the pole and it broke at the hole.
> NEVER DRILL A HOLE in these poles.