That may be OK in country that does not experience snow. I built a 437-MHz Helix using a wooden closet pole (painted) and it only lasted two seasons before the pole split from the wieight of the snow. Wood makes a good stiffener but really does not have the strength that fiberglass has.
But one need not worry mounting CP satellite x-yagis on a metal crossboom. WA5VJB analyzed and tested the concept proving that mounted in the X confiuration with cables dressed tight to the antenna and crossbooms negilible effects are seen (at least for satellite class operations). 73, Ed - KL7UW I have used a metal crossboom for years. At 02:24 PM 7/25/2009, Greg D. wrote: >Wooden pole for me. Just a regular closet pole >from the lumber yard. I've never been impressed >by the structural qualities of plastic pipe, and >putting a wooden dowel up the middle of one >still leaves much of the structural >responsibility with the plastic on the >outside. So, why not make it all wood? Heck, >if it can support my wife's wardrobe, it should >be able to handle a couple of antennas :-). How long of a span do you need? > >Greg KO6TH > > > > From: [email protected] > > To: [email protected]; [email protected]; [email protected] > > Date: Sat, 25 Jul 2009 17:14:20 -0500 > > Subject: [amsat-bb] Re: Cross boom question > > > > > > Amen: I have been aluminum cross booms for several years now. > > Jerry w0sat > > > > -----Original Message----- > > From: [email protected] [mailto:[email protected]] On > > Behalf Of Jim Jerzycke > > Sent: Saturday, July 25, 2009 4:36 PM > > To: [email protected]; Kevin Groth > > Subject: [amsat-bb] Re: Cross boom question > > > > This has been gone over a zillion times. > > Short answer; Mount them in an "X" configuration and don't worry about it. > > http://www.g6lvb.com/fibermetalboom.htm > > > > --- On Sat, 7/25/09, Kevin Groth <[email protected]> wrote: > > > > From: Kevin Groth <[email protected]> > > Subject: [amsat-bb] Cross boom question > > To: [email protected] > > Date: Saturday, July 25, 2009, 1:47 PM > > > > I have just finished building a set of 2m and 440mhz circular polarized > > beams to work the birds. (tired of standing in the heat and cold outside!) > > I tried to save a little bit of money by > building a wood dowel inserted into > > a sched 40 uv resistant pipe. I hung the beams on either side of the cross > > boom and it sags way too much and is ugly. I thought about using some > > eyebolts and some nylon cording for support to the vertical mast, but I'm > > trying to keep everything as clean as possible for the neighbors. I would > > really rather not have to purchase a > fiberglass satellite boom commercially, > > but if I have to, I will. > > > > > > > > I have a bunch of 1.75" aluminum pipe that would be more than able to > > support most anything I plan to add to the antenna collection in the future > > (1.2 and 2.4 ghz). My question is how much > of a difference would it make if > > I mounted the 2m and 440 beams in an X position to the aluminum beam? I > > have read some short answers that it would minimize the swr issue, but > > haven't really found an answer that I am comfortable with. Also, how would > > that effect a later addition like a 1.2 or 2.4 ghz antenna.? My current > > antennas are a KLM 2m-14c and a 435-40cx, both circular polarized and > > switchable RH and LH polarization. Does anyone have any experience with a > > metal crossboom? > > > > > > > > Thanks! > > > > Kevin > > > > N9EME > > > > Fort Worth, TX > > > > _______________________________________________ > > Sent via [email protected]. Opinions expressed are those of the author. > > Not an AMSAT-NA member? Join now to support the amateur satellite program! > > Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb > > _______________________________________________ > > Sent via [email protected]. Opinions expressed are those of the author. > > Not an AMSAT-NA member? Join now to support the amateur satellite program! > > Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb > > > > > > _______________________________________________ > > Sent via [email protected]. Opinions expressed are those of the author. > > Not an AMSAT-NA member? Join now to support the amateur satellite program! > > Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb > >_________________________________________________________________ >Bing™ brings you maps, menus, and reviews organized in one place. Try it now. >http://www.bing.com/search?q=restaurants&form=MLOGEN&publ=WLHMTAG&crea=TXT_MLOGEN_Local_Local_Restaurants_1x1 >_______________________________________________ >Sent via [email protected]. Opinions expressed are those of the author. >Not an AMSAT-NA member? Join now to support the amateur satellite program! >Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb _______________________________________________ Sent via [email protected]. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
