Colin and others,

I have tried different loops, on different bands, including half wave and
quarter wave wires.  My 40 meter delta loop worked extremely well.  The nice
thing about delta loops, if you have a tall enough ssupport for the apex,
you can put two up at right angles and switch between the two antennas.  You
get some directivity then and directivity is always a sign of some gain
regardless of how little.  Verticals, even trapped verticals, work
fantastically well if you put two of them in phase.  You can either end fire
or broadside or with relays, do both.  The broadside method is
bi-directional a you don't need to switch directions.  If they are installed
on a north south line, the signal with be straight east and west.  Typical
gain figures for phased verticals can be as high as 10 DB based upon
surrounding physical conditions.  I have worked guys using phased inverted
vees spaced a quarter wave apart who had tramendous front to back and thus
some forward gain.

For years, I ran three quarter wave sloping wires off the top of my tower.
They were actually my three upper set of guy wires which were insulated from
the tower and then I plugged another insulator in 60 feet down the cable and
then continued the cable down to my guy anchor several more feet down the
line.  Using a pair of relays, I switched from one wire to another and got
as much as 20 db from to back.  I was using a 65 foot tower but I have seen
this done with 50 foot towers.  The coax shield was grounded directly to the
tower but I ran a wire down the entire length of my tower, connecting to
section bolts all the way down, until I reach my ground system and wired the
ground strap into that as well.  That was a little trick I learned from W0ZV
who is now w4ZV.  The hot wire connected to the relays so as I switched from
one antenna wire to the next, the other two sloping wires were floating
above ground and thus acting like reflectors as the wire I was transmitting
on was serving as the director.  Certainly not as effective as a big beam
but a lot less trouble.  By the way, and I have confirmed this with others
using the same system, a side benefit, besides some gain and a lot of front
to back, is how broadband the antenna systems becomes.  I could literally
operate 300 KHz with under 2 to one.  That's 150 KHz either side of
resonance.  I also tried two half wave center fed sloping 40 meter dipoles
pointing, or sloping, from northeast on one side of the tower to southwest.
I got front to back switching from one feed line to another.  However, after
putting up the 40 meter delta loop later, I discover it worked even better
and was a lot quieter, too.  Full sized loops reportedly give us about 3 db
bi-directional gain.  This is why a lot of people that have tall enough
towers, hang diamond shaped quad loops off the towers.

Phil.
K0NX
Echo Link: 145 280