inter-reaction of hf antennas on a small lot
 

Dear Group,
I have two "main" antennas that I use in my small
lot. About 1/8 0f an acre
or say 70ft. wide by 140ft. deep. There are utility lines on one
side of my property.
One of the antennas is a full-wave loop for 80m. It is up about
30ft.,and feed at the
feedpoint by a 4/1 balun into good coax to the shack. The other
antenna is a dipole;
140ft long feed by ladderline to the shack. I have a tower(60ft)
and a couple of small
uhf and vhf beams also.
My question IS how are the near-fields and the far fields
INTEREACTING with the other
antennas ? What does one antenna DO the the transmit or recieve of
the other ?
How close can these antennas be to each other? What problems will
I get because
there is NOT enough space inbetween the elements ?


Paladin

inter-reaction of hf antennas on a small lot
 

Paladin wrote:

Dear Group,
I have two "main" antennas that I use in my small
lot. About 1/8 0f an acre
or say 70ft. wide by 140ft. deep. There are utility lines on one
side of my property.
One of the antennas is a full-wave loop for 80m. It is up about
30ft.,and feed at the
feedpoint by a 4/1 balun into good coax to the shack. The other
antenna is a dipole;
140ft long feed by ladderline to the shack. I have a tower(60ft)
and a couple of small uhf and vhf beams also.
My question IS how are the near-fields and the far fields
INTEREACTING with the other antennas ? What does one antenna DO the
the transmit or recieve of
the other ? How close can these antennas be to each other?

Interesting. During the PAQSO party we had a similar situation as we
were operating 2 stations simultaneously.

As far as I know, the answer is "not much" on transmit. Less on
recieve. Now if you are trying to use both stations at the same time,
there can be a lot of problems. Our antennas were a tribander used on 20
meters, and a 40 meter dipole. We were both running power, and the 40
meter station was reaking havoc with me on 20 meters. I made a stub to
put on the 20 meter rig, and all was harmony.

The distance from the dipole to the tribander was areound 40 feet at
closest rotation angle.




What problems will I get because there is NOT enough space in between the elements ?


Do you mean on the beams?

inter-reaction of hf antennas on a small lot
 

No,not the small beams. I'm mostly worried about the 2 large HF
antennas. The loop
for 80m encircles one leg of the linear-loaded dipole. I was under
the impression that
the "inside" of a loop on HF is the most important factor. I.E., a
circle is THE best loop!
The most area 'inside" makes for the best trans. and recieve.
No, I never use both at the same time. On
recieve,maybe. Do you think that
the SWR's would be different IF they weren't near each other!

Thanks for the interest !