"Joe S." wrote in
:

I am considering installing a stealth antenna on the porch of my
first-floor apartment and would like some suggestions. Here's the
deal.

-- First floor apartment.
-- Porch is a concrete slab, 10 X 10.
-- The ceiling of the porch is the underside of the balcony of the
apartment above me. It's all wooden.
-- Thus, the ceiling of my porch is 10 X 10, wood.

How about I build a 40-meter dipole, 67 feet long, feed with coax and
a balun in the center. Attach the coax and the balun to one of the
corner posts that supports the balcony above my porch. Run the two
sides of the dipole in opposite directions, but, instead of stretching
the wire straight as I normally would if hanging the dipole from
trees, towers, etc., what if I run the wires around the underside of
the balcony deck? This would give me a horizontal loop made up of two
pieces of wire, each 33.5 feet long, with the loop being 10 feet on a
side, thus, each end of the dipole would run around underneath the
balcony deck and come back almost to the center of the dipole.

That is -- the balun would be secured to one of the corner posts. One
piece of wire, 33.5 feet long would run straight out from the balun
along the 2 X 8 rim joist for 10 feet, make a 90-deg turn (20 ft), run
another 10 feet and make another 90-deg turn (30 ft), and end up 3.5
feet after the third turn. The other end of the dipole would do the
same thing, only run in the opposite direction. At the balun, the two
wires making up the dipole would run at a 90-deg angle to each other.
And, the two wires would overlap (or be only a few inches apart) for
27 feet of their length.

I probably didn't explain this idea too well but I'd like to hear some
suggestions. Thanks.

The real problem is going to be that winding the antenna back on itself
like that has the effect of lowering its radiation resistance. I ran it
up in Mininec and it comes out to less than 1 ohm at resonance. At that
rate, you'd be better off making a dipole of two screwdriver antennas
back to back.


--
Dave Oldridge+
ICQ 1800667