On Sun, 05 Jun 2005 16:57:03 GMT, GeorgeF
wrote:

I put up an 80 meter full wave loop using about 280’ of #14 wire in
almost a square.

Hi George,

That was certainly a good beginning, but questions abound as we
proceed.

Each end of the loop

How many "ends" does a loop have? This is something akin to how many
sides to a circle.

was soldered to an SO-239 connector.

One is enough, why two (or more, we still don't know how many ends
there are)?

This statement is enough to give pause. If there is more than one 239
inserted inline, it must of necessity break continuity of the loop.
This, then, means that you no longer have a loop, but rather a
fullwave dipole (presuming the loop has 2 ends).

I’m feeding the loop via RG-8 coax, about a 30’ run.

You say nothing of choking the feedpoint, and given the symptoms that
you describe, this sounds like a major omission.

In the 80 mtr band its 8:1 and in the 40 mtr band its 7:1.

Sounds like full wave dipoles (or even multiples). In other words,
consistent with previous descriptions.

My installation is far from ideal.

No one here has it any better, but by degrees. If you can do better
by trying harder, fine, but if there's no way to get the antenna
higher, or to blow away the obstructions....

Of course I can use my MFJ-949 tuner to get a low SWR on any band but by
doing so am I loosing efficiency?

In trying to tune full wave dipoles? Could be, but being so close to
the dirt is probably lowering your antenna's wicked Z to something
easier to tune (your efficiency is already dominated by ground loss).

I also notice that trying to tune the
loop the tuner seems to be very touchy!

Lack of choking at the feed point - or - you are tuning an
anti-resonant antenna.

I have noticed on 20 meters
the loop received on average about 2 S-Units better than my 20 meter
dipole. On 40 meters it receives almost 1 S-unit better than a 160’
randomwire. On 80 meters just slightly better than a 160’ randomwire.
(all antennas I’m comparing are all at about 20’ high).

Now all your previous complaints sound like whining. Do you want a
tuned antenna, or a gain antenna?

BOTH!?

73's
Richard Clark, KB7QHC

Now all your previous complaints sound like whining. Do you want a
tuned antenna, or a gain antenna?

BOTH!?

73's
Richard Clark, KB7QHC


There is one SO-239 connector, there is one piece of wire which is 280'
in lenght. On end of the wire is connected to the center pin of the
SO-239 connector while the other end of the wire is connected to the
braid side of the SO-239. Hope that clears up the configuration questions.

No I am not choking at the feed point. I was not told about a choke by
other hams who mentioned I should give an 80 meter loop a try. Is a
choke the same as a 1:1 balun? I was told (and found it also
illistrated in print) that I could directly hook 50 ohm coax to the
feedpoint. Tell me what I need to do to choke the feedpoint.

I had seen (believe it was one of the ARRL handbooks) that this antenna
should have no SWR higher than 3:1, mine is 7+:1 so I think either I did
something wrong or am missing something. Don't think I'm whining yet....

George

"GeorgeF" wrote in message
hlink.net...


Now all your previous complaints sound like whining. Do you want a
tuned antenna, or a gain antenna?

BOTH!?

73's
Richard Clark, KB7QHC


There is one SO-239 connector, there is one piece of wire which is 280' in
lenght. On end of the wire is connected to the center pin of the SO-239
connector while the other end of the wire is connected to the braid side
of the SO-239. Hope that clears up the configuration questions.

No I am not choking at the feed point. I was not told about a choke by
other hams who mentioned I should give an 80 meter loop a try. Is a choke
the same as a 1:1 balun? I was told (and found it also illistrated in
print) that I could directly hook 50 ohm coax to the feedpoint. Tell me
what I need to do to choke the feedpoint.

I had seen (believe it was one of the ARRL handbooks) that this antenna
should have no SWR higher than 3:1, mine is 7+:1 so I think either I did
something wrong or am missing something. Don't think I'm whining yet....

George


George,
Since you have an MFJ Antenna Analyzer, is there some frequency, regardless
of the SWR, where the reactive part of the impedance goes to 0? I don't know
about horizontal loops, but vertical loops are not 50 Ohm antennas.

Tam/WB2TT