-----Original Message-----
From: Bill Coleman [mailto:aa4lr@arrl.net]
Sent: Tuesday, January 01, 2002 5:52 PM
To: Stephanie WX3K; Towertalk
Subject: Re: [TowerTalk] Half slopers using a tower
On 12/31/01 4:59 PM, Stephanie WX3K at wx3k@ptd.net 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.
Somehow the math doesn't work out. 45 degrees at 50 feet should require
about 90 feetof wire. For 128 feet, it must be shallower than 45 derees.
>>>>>>>>>>>>>Please share your calculations !!!!!
>Anyone ever try this ??? The
>match I have is still unacceptable...2.5 to 1.....Any suggestions ?
What band? 40m? 80m? 160m? It seems too long for either 40m or 80m, and
too short for 160m.
>>>>>>>An earlier email mentioned 160 meters
Get an antenna analyzer on that puppy. Find out where it is resonant.
Trim the wire to make it resonant on the band you want it.
>>>>>>It appears to be resonant below 160 meters....I run out of range on
the MFJ259...It only goes down to 1.750
Note that the resonant point will be affected by the position of the
beam.
I have a similar half-sloper for 40m. It is about 33 feet of wire
attached at the 40 foot level of a 49.5 foot tower sporting an A3S.
Bill Coleman, AA4LR, PP-ASEL Mail: aa4lr@arrl.net
Quote: "Not within a thousand years will man ever fly!"
-- Wilbur Wright, 1901
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