From: gary@ke4zv.uucp (Gary Coffman)
Newsgroups: rec.radio.amateur.misc
Subject: Re: Attaching A Vertical To My House
Date: 11 Oct 92 11:48:53 GMT
Reply-To: gary@ke4zv.UUCP (Gary Coffman)
Organization: Gannett Technologies Group

In article <johnr.718729562@mik.uky.edu> johnr@mik.uky.edu (john s roberts) writes:
>I am interested in purchasing a dual band (144/440Mhz) antenna to
>mount on my house, but am at a loss about trying to figure out how
>to attach it to my house.  First I would like to know if the cable
>that I currently own (from a previous non-ham related project)
>will work for this antenna.  Here is what the side of the cable
>says:
>
>BELDEN M 9058 DUOBOND PLUS RG-6 TYPE 75 OHM E86432 (UL) CATV ---
>LL85170 CXC FTI QP
>
>I have no idea what this means, but I do have about a hundred feet
>of it and would like to use it if it is at all possible.

RG6 is 75 ohm CATV cable. While it would sort of work, you'd have
a VSWR of 1.5:1, it's not really the type of cable you want. Use
RG213 or Belden 9913 for the run. These cables are rated for the
service you intend to operate. 

>To mount the antenna to the house I am planning on using parts from
>Radio Shack unless someone would like to recommend a better source.
>I am looking at their 1993 catalog on page 100 and am wondering if
>the mount which attachs to the eaves (figure 7) would be very
>sturdy.  It attaches to the eave in three places.  If anyone sees
>any of the other attachments in the catalog or anywhere else that
>you think may be better please suggest them.  Also, one point about
>the attachments which are nailed or screwed through the shingles:
>how do you prevent the holes from leaking.

The Radio Shack chimney mount, the roof tripod, and their push up
masts are all suitable for mounting a large dual band base antenna
like the Comet 2x4MAX, which I highly recomend. The eave mount should
work for a smaller antenna like an AEA Isopole, though that's not
a dual bander, or for the smaller Diamond 50 series dual band antennas. 

Naturally, you want your antenna as high as possible above the roof
line. The chimney mount is a natural if you have a chimney. If not,
the roof tripod is a good choice. Use a 10 foot section of masting
with either, and with the Comet on top and you'll have a good antenna
setup. 

An alternate method is to use their 40 foot push up mast from the
ground. Attach the mast to the house with a 2x4 and a U bolt at
the highest point that you can. That will avoid having to use
guy wires on the mast. It will support a big vertical like the
Comet.

You don't want to nail a mount to the roof. You want to use large
screws for strength. The screws should go through the decking and 
engage a rafter for best results. With the roof tripod, there are 
"feet" on the tripod that rest on the roof. To prevent leaks, you 
smear roofing tar liberally over the feet after you have screwed 
them down securely.

Don't forget to ground the mast for lightning protection. A bare
number 8 copper wire down to an 8 foot ground rod is required.
Also be sure to use a proper lightning arrestor in the coax.
A Polyphasor IS-EMP-1 would do nicely. Blitz Bugs and the like
are pretty well useless for real protection of your equipment
though they may prevent your house from burning down. Radio
Shack doesn't have anything suitable, get your suppressor where
you get the cable.

Gary KE4ZV