Topband: 160m sloper problem
Pete Rimmel N8PR
k8unp@shadow.net
Fri, 24 Sep 1999 20:16:26 -0400
Ted,
I have used various slopers from 60 ft towers, but not 50 ft towers.
However, with the top loading on the tower, I found that the 160 sloper
was not resonant with 130 ft. It was longer. You have to experiment
with it to find out where it is resonant now, and then add as needed.
I also found that you need a good ground under the tower to make it work
well, too. Quarter wave radials are ideal, but a GOOD ground is just as
good, I have found... I tied my tower to a nearby metal well casing
that went down 60 feet, and the antenna worked MUCH better.
Most thinking now-days is that the sloper helps to load the tower and it
acts more as a vertical. If your sloper wire is more horizontal than
vertical i.e. the angle of thesloper is more than 45 degrees to the
tower, you won't have the half sloper, but a quarter wave end fed
antenna.
I suggest you try the following: Bring the 160 meter sloper wire from
the tower down at about a 30 degree angle to a conveinent height above
the ground... 10-15 feet. Then run it horizontally this way until you
run out of wire. You can even take it to the back of your yard and then
turn a corner 90 degrees. Just be sure to keep it roughly the same
height all the way. Then find out where it is resonant, and add or cut
as needed.
Tune it up, and away you go. It will not be very broad banded, but for
DX and contests if you can get it reasonable between 1.82 and 1.86 you
will be happy, I think. Also, remember that mismatch losses are not as
important at 1.8 as they are at 14 or 28 MHz.
To give you an idea of how my antenna worked, I was able to work KH6
from Sough Florida at sunrise on SSB during a CQWW contest running 5.0
watts. Yep, I was QRP and VERY happy for the mult!
Good luck & 73,
Pete N8PR
--
FAQ on WWW: http://www.contesting.com/topband.html
Submissions: topband@contesting.com
Administrative requests: topband-REQUEST@contesting.com
Problems: owner-topband@contesting.com