Al,
My uncle was in the same situation, living on the ground floor of an
assisted living apartment. He was not allowed any outdoor antenna.
I built him a magnetic loop antenna for 40m, using parts I bought from the
Home Depot, plus purchasing new coax for the loop. Since he only wanted one
band, I used a fixed capacitance made of coax to tune it to the band and
then built a tiny 'gimmick capacitor' using two pieces of the inner
conductor of the coax placed in close proximity of each other for the fine
tuning. He tuned by adjusting the gimmick capacitor (without power applied).
How did it work? Well, living in Oklahoma, he was able to consistently
check into his daily net for his rag chews and work around the Midwest with
a good signal. He only worked SSB with a 100w rig.
In the meantime MFJ has come out with a new magnetic loop antenna that also
tunes 40m. If I had known that at the time (January 2005), we would have
simply bought that instead of building.
You read all kinds of reports about these antennas, both good and bad. Of
course you can build something outdoors that works better, but this is
beyond a doubt the very best indoor antenna you can use and it is probably
just as good as a make-shift compromise antenna - though a couple of s-units
down on a good dipole.
If you want I can send you pictures of the loop I built for him.
73
Rick
-----Original Message-----
From: tentec-bounces@contesting.com [mailto:tentec-bounces@contesting.com]
On Behalf Of Al Gulseth
Sent: Monday, March 27, 2006 5:53 AM
To: tentec@contesting.com
Subject: [TenTec] Apartment antenna help
Greetings all,
I'd like some "brainstorming" help on an antenna for my dad. He is on the
third floor of an assisted living apartment facility, and we've been trying
to figure out if we can get him on the air from there (even on a limited
basis). Dad has been trying some indoor antenna setups (such as the Hamstick
type dipole arrangements) but apparently to no avail. I suspect this has to
do with the construction of the building (i.e. iron frame etc.)
I have talked to the head of the maintenance department at the facility and
he
seems to be willing to work with me on an antenna, but obviously it needs to
be as unobtrusive as possible as well as require as little alteration to the
building as possible. Since dad primarily like to operate 40/30/20M, what I
am currently thinking as a solution is a 22' wire (either horizontal or
vertical) attached to the outside of the building with a bead of clear
caulking or RTV. I would need to get this through a window, so I am
envisioning using a short piece of a "sandwich" of 1/2" - 3/4" wide thin
copper strip/flashing with thick plastic tape on either side so it can
(hopefully) be formed so that the window can be closed with it in place. I
realize that there would probably be some coupling to the window/frame as it
is aluminum. The 22' length mentioned is chosen as I am of the impression
that it is a good compromise length that is easy to load on 20-40M. This
would be balanced with a 22' counterpoise along the baseboard inside and fed
via an SCG (237?) autotuner placed where the antenna comes in through the
window. (Hope I'm making sense here with all this....) Another possibility I
have considered would be something similar to the B&W/MFJ apartment antenna
but with the matching network relocated to inside the building (again
possibly using the SGC autotuner along with the requisite counterpoise).
What is the possibility of this actually working (obviously on a rather
limited basis)? Any comments or suggestions? BTW this _is_ Ten-Tec related
as
dad would be using this with his Delta (probably at quasi-QRP levels of 20W
or less due to the possibility of TVI etc.)
--
TNX/73, Al
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