tower2.art

一个很小和天线计算程序

SUBJECT:  Towers, part two

    Towers are an interesting subject where antennas are concerned. We
have the commercial types which can cost you a bundle.  Then there
are the cheap-o second (fifth) hand towers older than most hams, that
we buy which, at best, offer a shakey support if not reworked properly.

    Antenna supports come in various flavors from trees, to push-up masts,
to full blown, motorized, telescoping, hundred footers capable of leaping
tall buildings in a single bound.  All are good depending on what you use
them for.  A tower rated for 10 sq.ft windload should be adhered to order
to save your equipment.  An antenna and rotor system mounted on top of a 
a tower can put a heavy torque (twisting action) on the tower.  Some
towers and masts can not take that torque and they crumble.  There are
ways to by-pass that problem and they will be discussed later.

    Guy lines can be a pain in the butt also.  Metal guys can play havoc
with various bands and ropes stretch.  These will be looked into also.

    I reposted my first tower article based on some problems I have had
here.  I won't be able to cover everything but I have a few friends that 
have some interesting towers that I will share with you.  

    AREAS TO BE COVERED:

    o         Trees
    o         Wooden towers
    o         Push-up masts
    o         Tubular towers
    o         Small Steel Crank-ups (7 & 9-in tri-angulars)
    o         Rohns
    o         Commercial Grade
    o         Monster Crank-ups
    o         Roof mounts
    o         Tilt-overs
    o         Trouble spots


NOTE:==>  I will be on vacation from June 6 to June 19.  In this period,
Mark Huff will be in charge of the echo.  If he wishes to post technical
articles he may.  While I'm gone, he wears the moderator hat, but

              "I'LL BE BACK." ;-)

-WS