[TowerTalk] Half slopers using a tower

[Ed Kucharski]

Stephanie,
My half sloper system is very similar to yours (I cut the sloper about
10 feet longer than calculated) and as N5AR suggested I trimmed it
for best SWR in the portion of the band I was most interested in.
I also noted that there was a relationship between the distance
above ground level and SWR.  I first tied the sloper off at about 5 feet to a
tree trunk so I could reach it without a step ladder but found the SWR improved
at about 9 feet up the tree (as high as I could safely reach with a standard
step ladder without tipping over on my uneven terrain).  I too avoided my
antenna analyzer and got plenty tired running between the shack and the
woods making measurements and length/height adjustments.  BTW my
SWR in the lower portion of 160m is < 1.5:1.
73 es GL,
Ed K3DNE




At 11:34 PM 12/31/01 -0800, dan hearn wrote:

>Stephanie: Think of your antenna as a dipole with the tower being one
>half of it. The tower is not a ground plane.You can expect to have to
>experimentally change the length of the wire to get a low SWR. In one
>antenna I built like yours, I had to make a 20 ft change in the wire
>length to reach resonance on 160m. You may have a problem using a MFJ
>259 type meter to measure SWR because of BC station pickup. If you see
>no SWR dip at any frequency, that is probably the reason.Use your rig on
>low power as a signal source. 73, Dan, N5AR
>
>Stephanie WX3K wrote:
> >
> > My tower is 65 feet with a Mosley Pro95 beam sitting just above the thrust
> > bearing. The "Half-Sloper" is hung at a 45 degree down at the 50 foot
> > level.....about 128 feet of wire...fed at the 50 foot level with 50 ohm 
> coax
> > and the shield ground right there on the tower. Anyone ever try this 
> ??? The
> > match I have is still unacceptable...2.5 to 1.....Any suggestions ?
> >
> > Stephanie R. Koles WX3K
> > wx3k@arrl.net
> > http://www.qsl.net/wx3k
> >
> > Assistant Skywarn Coordinator Somerset County, NJ
> > Mt. Holly Skywarn Technical Committee Vice Chair
> >
> > AN Wireless Self Supporting Towers are now available!  Windloading tables,
> > foundation diagrams and charts, along with full details are now at the
> > AN Wireless Web site:  http://www.ANWireless.com
> >
> > -----
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>
>AN Wireless Self Supporting Towers are now available!  Windloading tables,
>foundation diagrams and charts, along with full details are now at the
>AN Wireless Web site:  http://www.ANWireless.com
>
>-----
>FAQ on WWW:               http://www.contesting.com/FAQ/towertalk
>Submissions:              towertalk@contesting.com
>Administrative requests:  towertalk-REQUEST@contesting.com
>Problems:                 owner-towertalk@contesting.com



AN Wireless Self Supporting Towers are now available!  Windloading tables,
foundation diagrams and charts, along with full details are now at the
AN Wireless Web site:  http://www.ANWireless.com

-----
FAQ on WWW:               http://www.contesting.com/FAQ/towertalk
Submissions:              towertalk@contesting.com
Administrative requests:  towertalk-REQUEST@contesting.com
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