Mike:
Three different suggestions;
1) Try using 450 ohm ladder line for the sloper. Ground one end to the
tower and
the other to the inner conductor of the coax to the other. I get a
better match and
wider bandwidth.
2) If that doesn't work well enough, take a mobile whip tuned to the
desired frequency,
lift the ground from the tower, and place it to the mobile whip. (I
don't like this one
very much because it only lowers the swr for a very narrow bandwidth.)
3) Take an MFJ antenna annalyzer and determine the resonant frequency of
your tower.
If you need to lower it, their are all sorts of ways to do so. If it is
too low, place a remotely
tuned capacitor between the ground of the coax (and 450 ohm grnd lead if
you opted). Two
good sources of ready made remote tuned caps are (1) Heathkit (2) The
Cushcraft R3.
Both are used surplus nowdays. I buy every R3 I can find.
Jim Flanders
>-----Original Message-----
>From: Fatchett, Mike [SMTP:Fatchett.Mike@tci.com]
>Sent: Monday, July 28, 1997 11:56 AM
>To: 'towertalk@contesting.com'
>Subject: [TowerTalk] 1/2 sloper problems
>
>I tried putting one up this weekend. Could not get a decent SWR
>anywhere. I tried adding length and subtracting length. Tried moving
>the point where it attaches to the tower from 70 feet to 78 feet. I did
>not try to move is lower. I tried changing the angle as well.
>
>Tower is 78 feet tall with a 40-2cd at 90 feet and a C3 at 80 feet.
>
>I started out with a 130 foot sloper.
>
>Anyone have any suggestions?
>
>Mike
>W0MU
>
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