A Novel Method to Secure GRP-Poles
by Peter Bogner, DK1RP (www.DX-WIRE.de)
Telescopic GRP-poles (Glass-fibre Reinforced Plastic) without mechanical locking devices are very popular among radio amateurs,
because they are place-saving and of low weight. As the different segments are only kept together by “friction and pressure”
these connections often slacken after a few days and the pole collapses. Therefore securing the transitions with adhesive tape
is a simple and popular method to prevent the segments from slipping. However, the pole will soon be stained with remains
of glue and the protective layer of lacquer can be damaged.
Stainless steel hose clamps with rubber padding (as offered by Spiderbeam) are technically a good solution.
They solve the problem perfectly for very tall GRP-poles of 18 meters or more. However, a set of such stainless steel
clamps is quite costly and you should be very careful not to damage the GRP-segments with the metal clamps.
Therefore we have tried to find a cheaper simple alternative that can be used for smaller and lighter GRP-poles.
We found a manufacturer to produce for us a uv-resistant, rectangular rubber profile with a rectangular hole for
threading a 4.8mm cable tie.
After cutting the rubber profile to the proper size for the segment you get an ideal “economy-collar” to prevent
segments from slipping into the next larger element. As the rubber profile is too big for the thinner top-segments
of GRP-poles you can use scissors to cut and turn the hollow profile into two thinner U-profiles .
This novel technique is simple, inexpensive and reliable. The “rubber parts” can be marked with numbers and
used again and again with new cable ties that can be purchased for as little as € 0,04 per piece.
1,2 m rubber profile grey , uv-resistant, (OD 10 x 8mm, ID 6 x3 mm), only € 5,00
100 pcs. cable ties, black, uv-resistant, 4,8 x 300 mm, only € 4,00