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"between two trees"

Discussion in 'Antennas, Feedlines, Towers & Rotors' started by WA4RNT, Oct 14, 2009.

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  1. NA0AA

    NA0AA Ham Member QRZ Page

    A single pully IMHO is best as you don't have TWO counterweights to manage - I've got a 40/80 fan that takes only 10 lb. of counterweight - I use old barbell weights.

    I don't get winds of 150 but I get plenty of gusts to 60 plus ever rainy season and my current antenna has so far survived three seasons as rigged.

    I had pullys professionally installed in the trees to allow me to raise and lower the ends.
     
  2. AB3CV

    AB3CV Premium Subscriber QRZ Page

    I have one end fixed and the other through a pulley. I used 2ft x 4" piece of PVC pipe with a cap on the end to make my "bucket" weight. A bit of wire to form a bail at the top and make sure it hangs free of the tree trunk. Works very well. Surprisingly little additional weight required.

    My dipole is 88ft with no midpoint support and with 450ohm window line hanging from the middle.

    73

    jim ab3cv
     
  3. AE5JU

    AE5JU Ham Member QRZ Page

    I live 90 miles west of New Orleans, so I can speak of experience. Short time ham, long time SWL'er and AM/FM antennas outdoors.

    The antennas must come down before the hurricane arrives. The center of my multidipole is lifted up with a pulley. I just lower it, untie the ends (tied to eyebolts along a wood fence) and coil it all up. I lay the mast down.

    The FM antenna on the roof comes down, too.

    Also, for rope, 550 parachute cord does a great job. Black paracord holds up well to UV and simply disappears into the background. A google search will turn up lots of sources.
     
  4. VA2GU

    VA2GU Ham Member QRZ Page

    Personnally live on top of 1000' hill near the St Lawrence river in Quebec.
    The winds, well the trees up here know: they are all slanted east and have no branches on the west side. But i presently have 1/2 mile of wire, on 7 antennas, strung between trees and towers.
    You dont need very heavy guage copper wire. even for high power. So my biggest is AWG 16 stranded with PVC insulatioin (no oxydation).

    The secret for no breakeage is to use a light 1/8" poly line (the ones used for sails), supporting the wire at 6' intervals with black tape hoops; use these little wire screw clamps at each ant. end. Go over marine type pulleys (good quality) on each end, to two tree tops (i climb them and screw in an eye bolt near the top to hold the pulley),then route it down to a nearby tree trunk (to get the rope away from the supporting trees), then through another smaller pulley to a weight dancing up/down near the ground. When the snow falls (up to 8 feet of the stuff here) i raise the weights so they keep floating.
    You have to leave slack in the poly on the antenna, because it stretches when you raise the antenna up. The copper wire has to hang a little bit slack when the antenna is up.
    Have used this method in BC with a 5 element vertical array CVA (400' span, but 3/16" line); was up for 5 years till I moved.
    .
    Here i have a 1200' span between two 1000' hills, supporting a 3 element 160m vertical array CVA (not operational yet, but been up for two winters so far; uses 1/4" poly line there). The wind funnels there, believe me!!
    Have been using this method for over 20 years, 15 of which were in VE7 land with 150' tall fir trees (yes 150' high there!!).
     
    Last edited: Oct 29, 2009
  5. K9STH

    K9STH Platinum Subscriber Volunteer Moderator Platinum Subscriber QRZ Page

    The question about pulleys and so forth supporting wire antennas came up on one of the E-Mail reflectors and the suggestion about using window weights was mentioned. Someone actually found a source of new weights! They are a "bit" pricey but such weights are still available.

    For information go to

    http://windowweights.com/

    Glen, K9STH
     
  6. WR5AW

    WR5AW Ham Member QRZ Page

    Or go to a place that specializes in old house salvage like the one in Fort Worth - Old Home Supply. Used to be a regular customer there.
     
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