Larry writes:
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I was wondering if anybody has suggestions on how to run hardline 1/2" &
7/8" up a teescopic tower. I have just instaled a tubular tower that I
plan on using for some UHF and SHF antennas. The tower is about 20' and
extends to 55'. Any useful suggestion will be helpful.
Thank es best 73,
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Larry Lipitz
NY2US
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I have a US Tower MA550MDP on a rotor base. As it is motorized, I run it up
and down frequently. I use the US Tower coax standoffs, but I use them
differently than most others I have seen. Most guys seem to connect the coax
to each standoff and install the standoffs at 30 degree radial angles to each
other. When they lower their towers the coax forms large loops between each
level of the tower. This would be a serious no-no with hardline or even 9913.
I don't attach my feedline to the standoffs, I just run it through the "hoops"
and I stack the hoops directly on top of each other. I stand under the tower
as it is comming down (I hardly ever use the remote control in the shack) and I
stack the feedline on the ground in huge figure 8 loops. I also feed it back
up by hand when raising the tower.
This is the only way I know of to use hardline or 9913 with a crank up tower
and not damage the cable by excess flexing. The LMR folks have some new cable
out now that has a stranded center conductor. One type is LMR400 Ultraflex.
This is standard RG8 (9913) size stuff with losses similar to 9913. They have
larger versions as well. I believe the next size up is LMR600 Ultraflex, and
there may be even larger sizes of the Ultraflex version. You might consider
these if the above method won't work for you.
73 - JC,k0hps@amsat.org
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