[FLARES] Portable Antennas for Shelters

[Keith]

Ron, et.al,

My comments are interspersed below.

Keith, KF4BXT



-----Original Message-----
From: Ron Wetjen
Subject: Re: [FLARES] Portable Antennas for Shelters

Didn't want to get into too much detail, since the "reasons" we can't 
put up permanent antennas doesn't really matter.  But several have 
asked, so here goes.

	Just a bit of soapboxing here:  I think the reasons ARE important at
times 	because many of us may have experienced and successfully traveled
through 	such problems. It gives us the details needed to fully
understand the 	issues we each face and helps in the brainstorming of ideas.

We are on a "tiered" shelter system.  <portions clipped> The difficult part, is
that these shelters may change from year to year. <portion clipped>

	THAT DOES create a huge problem for you installing permanent antennas.
Also 	frustrating is pre-planning for operator location.

Also, during Hurricane Charley, several schools suffered antenna damage 
on their towers.  If an amateur antenna suffers damage during a storm, 
without a backup, they'd be off the air.

	Backup plans are always necessary with EMCOMMS and should be part of
your 	ARES/RACES meetings and training session discussions. We always think of
losing power so we tend to think of backups regarding power sources. Some
do think about backup radios but few think of alternative antennas and 	fewer
actually have them on hand.

I also suspect, there may be "politics" involved ... but would hope that 
politics doesn't play too big a part when it comes to the safety of the 
community.

	Politics could certainly play a part...more over who's funding it, who's
providing the labor, etc. If that's a real objection, then look for funding
and installation sources. Maybe the DEM, through Homeland Security monies
can fund the hardware, or at least help.  ARES/RACES members, along with a
local citizens volunteer group (CERT perhaps?) could provide the
installation labor.

	The whole thought of being able to provide EFFECTIVE radio
communications 	requires that "some" attention be given to the physics of the
subject.  	There are certain "laws" about radio propagation that must be
considered.  	Education of the non-radio types is needed. You can't hide
antennas below 	ground and expect them to work. What if Emergency Management was
told they 	have to provide certain functions such as backup radio systems
to contact 	other counties or the State EOC yet they were told they couldn't
put up 	that Satellite antenna for ESATCOM outside.  It had to be kept indoors
because it's too expensive and might be damaged.  Well, it won't work. Or
they had to have immediate informational access to each ESF position in the
EOC and the database of all issues being worked yet they couldn't get the
computer system needed because it's expensive.  Many times the "politics"
of the issue results from not understanding the issue fully.

So, what's needed is something that might be part of a jump kit, which 
is a compromise between a permanent or temporary antenna outside (which 
may become damaged during a storm), and an HT and rubber duck inside 
(which we all know doesn't work).

	One thought here might be a compromise of sorts. The problem is
two-fold. 	You want that outside antenna primarily to give you the best
shot at 	hitting the repeater or working simplex.  Outside, up in the
air, does work 	best. In all these cases you'll have to do some experimentation
and trials 	at each shelter location to see what works where.  The problem
with outside 	antennas is getting the feed line inside without leaving a
window cracked 	(if there's even a window there that could be used) or a door
open lest you 	get your feedline damaged. Try getting a "permanent" coaxial
entry point 	installed at each shelter.  A simple capped sleeve through the
wall would 	help. You could then run the coax inside safely and come up with
portable 	masts or attachment procedures outside. If there's slider
windows (double 	hung/single hung) you might make up "custom" bulkhead
blanks with a coax 	barrel connector installed. Open the window a bit,
install the bulkhead 	insert then use sliding window locks to secure the
window. Problem here is 	many shelters are being fitted with shutters.
That sends me back to the 	entry sleeve in the wall.
	
	Try a glass mount antenna system and see if that works. Might work for
repeater work IF location is okay but may not work at all for simplex.
Look for ways to suspend J-pole antennas (twin-lead antennas work fairly
well and can be hung above or below the ceiling, from roof trusses, etc and
can be built into pvc pipe for protection.)  ANY indoor, temporary antenna
system will have to be site tested beforehand to see how it works and where
it will work. Problem here is the construction techniques for most newer
public/commercial buildings....heavy concrete block/brick, with lots of
steel reinforcement and metal trusses, studs, roofs, etc.  Here again, the
laws of radio physics must be taken into account.  We can't change the way
radio waves, at VHF and UHF frequencies, react to being broadcast from an
indoor bunker.  There was a recent article in QST (last month or two I 	think)
about using plate glass handling heavy duty suction cups to make a
temporary antenna support mount. I've picked up a couple of such suction
cups (say that 3x fast!) from our local Harbor Freight store. Might provide
some good portable mounting ability. We have permanent antennas (dual-band
Arrow J-Poles) mounted on our school shelters now. This was a 5 or 6 year
effort to finally get everything together to "get 'r done" but we finally
did. In past years we tried a pvc constructed mast that could be hung over
the edge of a flat roof, such as a covered walkway. You still need to have
some way to lash it down to something solid. PVC can flex quite a bit and
will eventually get brittle and break.

	IF field trials can't give satisfactory results for indoor antennas and
your EOC communications link via repeater or simplex, one thought might be
you'd have to establish relay stations in-between in addition to your 	shelter
operators. There you might look for public places (fire stations, 	police
sub-stations) for permanent radio locations that DON'T change from 	year to
year and allow them to act as relay points for shelter comms.  	Cumbersome of
course, but may be the only solution.

	Bottom line...arguably outdoor antennas do work best, J-poles are
probably 	the most cost affordable antenna to put up.  Can be commercially
purchased 	(recommend Arrow Antenna J-Pole) but can be easily constructed
with twin-	lead.  Key thing is you'll have to do a lot of running around
field testing 	antenna locations at each site and potential site. Or course,
education of 	your ARES members in the key things to consider when setting up
a portable 	station and locating the antenna and operating position will
also go a long 	way.  Innovation and adaptation are key hallmarks of the Amateur
Radio 	community and should/must be the basic core attributes of ARES members.
We 	need to reinforce knowledge in WHY things work or don't work, rather
than 	just be a plug and play operator.

Keith, KF4BXT
Seminole Co. ARES/RACES (former EC)


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