Topband: Half slopers ???

[Gene Smar]

Doug:

     I have both types of antennas but on different bands.  On 80M I use a
half-sloper wire off the 64 foot tall tower tapped at the 55 foot level.  I
selected that spot on the tower because that gave me the best match on 80M.
On 160M I shunt-feed my tower, with the tower tap also at 55 feet.  I have a
large transmitting variable capacitor between the coax center conductor and
the shunt wire - actually two parallel wires (see
http://s83.photobucket.com/user/ersmar/media/Shuntwires.jpg.html?sort=6&o=33
.)  

     As my two lowband antennas are on different bands I can't answer with
personal experience how one design vs the other will function on 160M alone.
However, in thinking about your question, I conclude that having a loading
coil in the 160M wire would be a source of loss that might be avoided with a
separate antenna designed for Topband.


73 de
Gene Smar  AD3F



-----Original Message-----
From: Topband [mailto:topband-bounces at contesting.com] On Behalf Of Ryszard
Tymkiewicz
Sent: Saturday, April 02, 2016 4:56 AM
To: topband at contesting.com
Subject: Re: Topband: Half slopers ???


> Hi,
>
> I am trying to work on 160m (also on 80m) from a city lot.
>
> I have been reading about half slopers in the ARRL Wire antenna 
> classics B (chapter 7).
>
> I have a 50 ft grounded tower available and can run an sloping wire 60 
> ft
> (1/4 wl on 80m) then add an 80m trap and more wire to work 160m.
>
> Any thoughts about this kind of antenna?...
>
> Thanks,
>
> Doug, CO8DM
>
> ______


Doug I was using half sloper on 160m for 20 years and it was not bad..I
worked #300 countries ..BUT a few years ago I tuned my tower with a shunt
and when comparing both antennas during many QSOs a difference was between 1
to 2S for shunt fed tower. The tower has been 22m high with quite big hat of
TH6DXX and 6 el 6m Yagi  ( that time).
Anyway the tower has been too big for 80m and I still use two half slopers
for 80m aiming in opposite directions...I've thought there will be a
difference between them but its is only about 1 - 2 dB.
Of course I have many radials around but my garden is just 30 x 30 m.

                                     73 and GL
                                           Rys
                                      SP5EWY

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