Steve GW4BLE wrote:
>
> Anyone have experience of using a multi-band sloping Vee beam?
>
> In preparation for National Field Day here in the UK we are considering
> something along those lines.
>
> We are restricted, by the contest rules, to one antenna which must be a
> single element having not more than two elevated supports and not exceeding
> approx 35 feet above ground at its highest point.
>
> We usually have a doublet, but with no real restriction on space thought to
> experiment with something different this time...
>
> A sloping vee with the far ends moved around to favoured directions could be
> an option.....
>
> Any observations out there ?
>
> Thanks
>
>
> Steve
> GW4BLE
>
Steve
I use a Cobra Sr ultralight <http://www.k1jek.com/> which is 50' agl at one
end and 35'agl at the other end fed with 100' of ladderline thru a 9:1 balun
into a Dentron 3000A tuner via coax. Handles up to 1kw QRO.
I can be heard by and can hear all Army MARS stations in the State of Texas
which is about 3 times the size of the UK and its outlying islands, and by
the surrounding states. It would easily handle an area of the Panhandle of
Texas which the UK would easily fit into. basically, the higher you can get
a dipole off the ground, the better you are going to hear/be heard.
Minimum in my opinion is 50' at center with the ends at 25'
But you can center support the Cobra Sr at 35' if that is your max allowable
and run the 70' legs out on guys about 100' or so which could raise the ends
to about 20'. you will have to experiment with that. point is, if you have
the space to run end guys far enough, you can get the ends up to the min of
25' and have a good antenna which should get you into Western EU if you wanted.
Personally, I like my sloped center fed dipole as it is probably the best
wire antenna I have ever found. I use it primarily between 75 and 90m but
often up to 40m. It does require an external tuner!
This is imnsho, the BEST antenna for FD or for base operations. Unlike the
G5RV, it will easily work 5mcy and all NON HAM bands as long as you have the
tuner. I am guessing that after about 6 mo since introduction, about 20% of
Texas MARS stations are using this antenna.
fwiw
chas
chasm@texas.net k5dam Houston, TX
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