Hi Wayne:
Perhaps we can help each other! :) See www.spiderbeam.com for DF4SA's new 40' heavy duty telescoping fiberglass pole that may fit the bill. Click on the banner header (in red) when you open the page. [See below for some of the blurb copied from the site]. I recently bought Con's (DF4SA) spiderbeam kit (5 band version) and can testify to the very high quality of components, including the fiberglass tubes used in the 10m (33ft) boom and spreaders. The 40'ft telescoping mast is made of similar construction and material. This pole is not 'moterized', however, and may be too lightweight for your intended use. So Wayne, if you do find an aluminum 30'-50' telescoping mast (moterized or not) I would be VERY interested to learn about it, for use with the above mentioned Spiderbeam in 'portable' (or rather 'transportable') situations like field day and longish trips to exotic places. While there are several European sources for aluminum push-up masts in the 33' to 50' range at reasonable (Euro) prices, I have so far found nothing equivalent here in the States. All I can find are VERY nice military kits (with military prices out of my league), or surplus masts that are not particularly lightweight or telescoping. Here's Con's blurb: "In our continuing efforts to make our portable equipment even more rugged and durable we have now developed a new "HEAVY DUTY" version of our well-known 12m pole [40ft]. The first prototypes were tested last November/ December during 120km/h winds at the North Sea coast and performed just great! These are very strong poles, with a much greater wall thickness (up to 2mm!) than the usual "fishing rod" types. They are wound with a special reinforcing winding technique (several layers of fiberglass are wound in alternating direction (criss/cross winding), thus greatly increasing lateral and linear strength. Stronger joints are achieved by a much larger overlap between the individual tube segments than usual. These heavy duty poles are very well suited for building 40/80/160m wire GP or inverted L antennas. They can also easily support temporary lightweight 1 Element Quad or Delta loops for 20-10m, and dipoles for all bands, especially when used with open wire feedline. (Most baluns would be somewhat heavy). Even the top segment is 8mm in diameter (and 1.4mm wall thickness), so the poles can be used to their full 12m length - unlike other poles where the top segment is very thin as a whip. During our tests we were able to put 80m inv vee dipoles (made from 1mm diameter enameled copper wire (AWG 18) and open wire feedline) RIGHT AT THE TOP of the 12m pole... No way you can do this with a regular "fishing rod"! At 9-10m height, the poles can easily support small VHF/UHF yagis. The best (and cheapest) wire to use for such applications (verticals, loops, dipoles etc.) is AWG 18 (= 1mm diameter) enameled copper wire or similar. Thin fishing monofilament (1mm diameter) or similar rope is very suitable for guy lines. Of course, a single person can still put up these poles very easy within minutes. Pole dimensions: full extracted length (height): 12m (40ft) transportation length: 1.18m (3ft 10'') weight: 3.3kg (7lbs) bottom diameter: 55mm (2 1/6'') top diameter: 8mm (1/3'') wall thickness: 1.4 - 2mm (1/18" - 1/12") number of segments: 12 segment length: 3ft 10" (1.18m) Pole material: Black Fiberglass, UV protected Price: 79 EUR" Hope this is of some help, 73 John, N6JW K2 #3290 --------------- Hi all, I'm hoping to put up a compact, lightweight rotatable dipole or 2-element yagi for 20-10 meters. . . This calls for a 20 to 30 foot telescoping mast made of small-diameter tubing. . . Anyone have suggestions on where to find such a mast? Thanks, Wayne N6KR _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
I can recommend the pole in www.spiderbeam.co.
I have had some of this kind, even so-called "strong". Normally they are limited to 10m(33ft). In practise you have to take out 1 or 2 topmost parts. So you end somewhere to 8m (27ft). But now: this pole is solid enough for wires up to 12m (40ft). Here we have a field-day winner. Metal mast is a must if a beam is in question. But gain is rapidly decreasing when going down from 12m (40ft). You loose the power gain but of course beam has directivity, if that is important. So my rule is: lightweight horizontal over 10 meters for 14 MHz. To-day my favorite is inverted L (10.5 + 10.5m), voltage feed down next to XCVR. No heavy feedlines. Makes quite a weapon for 7 and 14 MHz. One end tied to this pole, the other to second pole or tree. 73, have fun Benny, OH9NB _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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