[MilCom] HF Antenna for Ute monitoring orientation question

[Duane Mantick]

comments inserted below 

-----Original Message-----
From: milcom-bounces at mailman.qth.net [mailto:milcom-bounces at mailman.qth.net]
On Behalf Of Ron
Sent: Thursday, December 02, 2004 11:02 AM
To: Milcom at mailman.qth.net
Subject: [MilCom] HF Antenna for Ute monitoring orientation question

    Have pulled down my Grove Skywire from the old house in NE MA which had
one end north and the other south so it was actually oriented best for
east/west reception?

>>>>>Assuming the question mark wasn't a typo, then yes that is correct.
But only
in very broad terms - assuming that this was a wire dipole.  The only really
hard null on a dipole is straight off the end, and even that will usually
allow
some signal reception.  Wire dipoles aren't particularly directional.

 Had no other options due to small lot size and tree locations. Worked it
with a Uniden SW radio and a RS DX392 with fairly good results across the
frequency range but with 1/3 acre lots and lots of neighbors all around had
considerable interference. Only used it for mil ute monitoring.
    Now have 2.5+ acres in southern NH with closest  neighbors about 300+
feet away to East, South  and West.
    Easiest mount is from house to barn, again almost identical orientation
as MA location, but could also go with one end  ENE, E or WNW by using house
to trees. Will be hooking it up to a Gary Weingard refurbed Racal 6790.
    What is the 'best' option for single antenna orientation?

>>>>>I would say orient the antenna as physically north and south as
possible.
This will make the major lobes electrically east and west.  Unless you are
planning
on listening over the north pole or to south america, that should give you
adequate
coverage of CONUS and perhaps over the Atlantic and into Europe on HF.

    Should the Longwire be grounded to a grounding rod before feeding into
the house/radio to help remove static?

>>>>>Arguably, you should ground from the RADIO to an internal ground system
in your "shack" and then tie THAT to an outside ground rod.  Don't ground
the
antenna except when you aren't using it.  Again, arguably, if you ground it
when not in use it might deflect a lightning strike AWAY from your gear.
Some
might also point out that letting the antenna "float" when not using it,
just
leaving it disconnected, can be equally effective at warding off lightning
hits.

>>>>>As for ground removing static, if your wire antenna is a dipole with a
coaxial feed, the shield of the coax will typically connect to chassis
ground
of the radio when connected to the radio.  If you have chassis ground
actually
"grounded" as I suggested above, then the shield of the coax will help drain
off
static charges that might build on the antenna. But if by "static" you mean 
"noise" generated from manmade sources it won't matter much.  There are some
"noise filters" out there; check out MFJ.

    Any other tips from you folks who have been there, done that, got the t
shirt (or fried the rig) and would like to keep me from reliving your
experiences?
    Any suggestions for a 'better' antenna type/make?
    Contact off list if preferred and pointers to any web sites (please, not
nerd level ham antenna discussion sites!) that will give further basic HF
reception antenna installation/operation guidance appreciated.

>>>>>Speaking as a "nerd ham"  :-)   (30+ years of Amateur Licensing and
several
years before that in CB, all the while doing some light SWL and scanning) I
can
tell you this:  You may think that the ham sites can be snotty, arrogant and
elitist at times (and, you would be right!) BUT when it comes to people who
know how to dig signals out of the mud you would be hard pressed to find
better
advice.  The most effective, inexpensive antenna for HF listening is
probably 
still the dipole without a doubt.  There are a lot of variations on the
basic
dipole theme that have slightly different characteristics but for the most
part,
they will all give good service.

    TIA, Ron  Southern NH 

>>>>>Ron, feel free to shoot any additional questions you may have.  Some of
us nerdy hams just might be happy to help !!!  :-)  :-)

Duane
WB9OMC
Lafayette, IN


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