[HoustonHam] Rohn tower

[Ben Worrell -ne5B]

Chas,

My primary HF antenna is a dipole (3 dipoles / 3 bands on one balun) fed by
RG58 Coax.
This is mounted on a 30 foot pole (3 pieces of 10' RadioShack mast) with a
pulley at the top and heavy string (200# trotline) in a flagpole type of
loop. - makes it easy and quick to raise and lower the 3 dipoles.

Coax just below balun has 3    4" loops taped and this is hung below the
balun with string (so the end connector has 0 strain on it),    To keep the
coax from blowing, I secure it to the mast with the same trotline string
loop that holds the antenna up.



The 3 different dipoles are  separated by 25-30 degrees and don't interact
with each other.
(40m, 75m and 17m)
I can lower the assembly  and remove one or two dipoles and raise it back up
and the remaining dipole is still resonate.

No guy wires - the dipoles sort of act as guy wires, but the pole will move
around about 3-4' or more in a strong wind.    The RadioShack mast material
fits over a 3' piece of Galvanized waterpipe that is driven about 2' into
the ground.
This arrangement has worked well for me since 1998 in 2 different locations.
(I added the 75m wire to the arrangement about a 6 months ago).

GlennMartin Engineering - which sells the Hazer system has a "tagline" they
sell that supports the coax.   (Hazer rides up and down Rohn 25, allowing
you to raise and lower a beam antenna without having to climb the tower - a
hand or elec winch and a cable do the work)  my friend mike WB4HUC
http://wb4huc.home.texas.net/station.html has one.   He had pics of it on
his website, but I see that he's redoing the whole thing with no pics at the
moment!



Also from what I recall I think the standoff for 450 ohm ladder line should
be about a foot......
300 ohm TV line may not need that much....

73 Ben - ne5B



----- Original Message ----- 
From: <chasm at texas.net>
To: "Amateur Radio in Houston TX area" <houstonham at mailman.qth.net>
Sent: Monday, January 17, 2005 10:22 PM
Subject: Re: [HoustonHam] Rohn tower


> On Mon, 17 Jan 2005 21:45:16 -0600, "Brian K. Gaskamp"
<ka5bkg at sbcglobal.net>
> wrote:
>
> >Antenna here is a dipole on a 25 ft mast...legs running East and
West...its
> >a G5RV..I use it for 40 and 80...get great signals reports..
> >I use the one that runs 300 ohm twin lead, into a 4-1 balun...then RG8X
coax
> >out the other side.
>
> that is good but what do you do with the coax to keep it from blowing in
the
> wind and breaking?
>
> thanks
> chas
>
> --
> Charles L Hamilton,  chasm at texas.net  Houston, TX
> for swapping, selling, buying firearms related stuff
> subscribe to the "rummage sale",  try this url -
> http://www.yahoogroups.com/subscribe.cgi/jagdhutte
> to post to the list, To: jagdhutte at yahoogroups.com
> ______________________________________________________________
> HoustonHAM mailing list
> Home: http://mailman.qth.net/mailman/listinfo/houstonham
> Help: http://mailman.qth.net/faq.htm
> Post: mailto:HoustonHAM at mailman.qth.net
>
>