I am working on my low band antennas as its clear that most DX and the
ability to win contests will depend on having a good low band signal.
On 40 I am set with the Cushcraft 2 el 40 )older version) at 87.5 feet. I
do need to fix the cap hat on one side of the reflector.
On 80 I have a half square broadside N/S and I can feed either side as a
dipole for close in work. The west side hits Mississippi and Texas with
meter pinning signals. I have put up one old Mor-Gain 80 that is vertical
with the bottom half sloping slightly toward Europe. This worked well this
past weekend. I did have up a second Mor-Gain also mounted as a vertical
dipole (they are only 66 feet long). This bottom half of this one was sloped
toward the west. I could use each individually or as end fire toward 45
degrees. Only NO8D ( 3 el at 180 feet) was stronger on that recent S07
Expedition. EI6S gave me +40 and John ON4UN at OR4T said I was as loud as
W3LPL. So that one goes back up in a couple of weeks.
160 is the problem. The wife has decreed that (after listening to K5UR a
few years ago) no ground radials. So this is why the vertical dipoles and
half square on 80. I have a Spi-Ro 100 foot dipole up 70 feet as a dipole
L (W4RNL likes the half wave L). PY3CEJ said I was like a local at his
place last May on SSB (1850 Tom ). I tried another as a K8UR/W9LT/WA7LT
side wise V but part was below the house and the angle on the bottom was too
small. However it worked CN2R, EA8BH, and CU2CE so it worked some. I do
plan to put up a MULTEE (a vertical T made from ladderline. I found the
ones in the ARRL and W6SAI antenna handbooks tunes at 1912Khz and since I am
not a JA I needed to get it down to below 1850. I found that lengthening
the horizontal legs did nothing once you got to 70 feet so the vertical
portion needs to be longer.
At 60 feet (original was 52 feet) the antenna tuned to 1863 Khz. So I feel
that 64 or 65 feet will do the trick. The ladderline does the same for the
resistance of the antenna as W6SAI found with 300 ohm line so instead of 10
ohms the transmitter is looking at 40 to 50 ohms. This does not help
radiation just the resistance the transmitter is looking at. At 65 feet I
can keep the bottom about 20 feet off the ground. I can then use the Spi-Ro
loaded elements as elevated radials (4 to 6). I also can get the antenna
away from the house as a vertical next to the house overloads the house with
RF. A big tree in the far backyard will do the job nicely. Now all I need
is a tree climber.
I do have a K9AY low band listening array so am set there as the horse farm
where I had my beverages has been populated by houses.
Since many of SECC and SEDXC are expert at antennas, I am looking for
additional ideas.
especially on 160.
73 Dave K4JRB
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