[Towertalk] 40 meters (Wire Beam)

[n4kg@juno.com]

The 2L40 Wire Beam I use on Field Day is designed for good gain
and low F/B.  

Maximum Gain occurs with 0.15 WL spacing for a reflector which
comes to 20 ft for 40M.  The reflector length is 70 ft and is also 
installed as an inverted vee on a rope boom between two 50 ft 
lamp posts.  I pull the ends out as far as possible (about 200 ft
each side) using very light nylon cord.  This yields a 150 degree
apex angle which comes very close to the performance of level
elements.  Higher would be better, but I have been very pleased
and surprised at how well this antenna performs for us with only
100 W.  

I feed it with an even multiple of 1/2 WL of RG59 (since I have plenty) 
and use the internal antenna tuner in our radio to tune out the 2.5:1
SWR.    Inserting a 1/4 WL matching section of 50 ohm line followed by
any length 
of 75 ohm line would probably result in a better SWR on 40M but a higher 
SWR on 15M.

Tom  N4KG

On Fri, 28 Jun 2002 Joe Brown <joe.brown@gordmans.com> writes:
> Can you give me the details on how the reflector is situated with 
> respect to  the driving dipole? Spacing, etc. is the reflector also a
vee?
> 
> 73, Joe W0DB
> 
> 
>  -----Original Message-----
> From: n4kg@juno.com [mailto:n4kg@juno.com]
> Sent: Friday, June 28, 2002 12:01 PM
> To: TOWERTALK@contesting.com; ve4xt@mb.sympatico.ca
> Subject: Re: [Towertalk] 40 meters
> 
> 
> Hello Kelly,
> 
> For Field Day, I used a 50 ft high inverted vee (120 degree apex 
> angle)
> aimed at W8 and a vertically polarized Delta Loop aimed at W6.  The
> Delta Loop gives me 6 to 10 dB improvement to the West Coast after
> 11 pm local time.  The antennas are approximately perpendictular
> to each other.  IMHO, it is NOT worth making a Horizontally 
> Polarized
> Delta Loop unless you can get the apex much higher (80 to 120 ft)
> since the effective height is so close to the *bottom* wire.  This 
> is
> not a problem for VERTICALLY polarized loops.
> 
> For the last two years, I've added a 70 ft reflector to the inverted 
> vee
> and it has been a KILLER, allowing us (K4BFT)  to overtake the
> 20 / 80 CW station for the first time ever.  We use the 40M inverted
> vee in 15M where it performs quite well.  With the 120 degree apex
> angle, the pattern nulls fill in fairly well, giving us an almost 
> omni-
> directional pattern on 15M.  We use the 40M Delta Loop on 10M
> to pick up a few extra contacts on that band as well.
> 
> Tom  N4KG  in ALA
> 
> On Thu, 27 Jun 2002  "Kelly Taylor" <ve4xt@mb.sympatico.ca> writes:
> > Hi all,
> >
> > Considering options for SS this fall and I'd like some opinions.
> >
> > Options somewhat limited to choice of following:
> >
> > Inverted vee, apex 50 feet versus 1wl loop, hung from same 
> yardarm.
> >
> > First question: is it even worth doing?
> >
> > If so, diamond shape or delta?
> >
> > Thanks,
> >
> > 73,
> > kelly
> > ve4xt
> >
> >
> > _______________________________________________
> > Towertalk mailing list
> > Towertalk@contesting.com
> > http://lists.contesting.com/mailman/listinfo/towertalk
> 
> 
> ________________________________________________________________
> GET INTERNET ACCESS FROM JUNO!
> Juno offers FREE or PREMIUM Internet access for less!
> Join Juno today!  For your FREE software, visit:
> http://dl.www.juno.com/get/web/.
> _______________________________________________
> Towertalk mailing list
> Towertalk@contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk


________________________________________________________________
GET INTERNET ACCESS FROM JUNO!
Juno offers FREE or PREMIUM Internet access for less!
Join Juno today!  For your FREE software, visit:
http://dl.www.juno.com/get/web/.