Bill Coleman commented:
> On Oct 20, 2005, at 5:06 PM, <ku8e at bellsouth.net>
> <ku8e at bellsouth.net> wrote:
>
> > The 40 meter vertical might change this weekend as I get ready for
> > CQWW SSB.
> > I am thinking of the one following 40 meter antennas depending on
> > how much room I find out I have :
> >
> > 1) 2 Half squares - one pointed NE/SW , the other NW/SE
>
> Do these have to be worked against ground? K4SB Definitely YES
>
> > 2) 3 el wire beam to NE - inverted Vees
>
> You'll need to get the apex up 50 feet or more for the pattern to
> become effective. K4SB Not very effective at all. At 50' most of your signal
> is at radiation angles in the
40s.
>
> > 3) 2 el quad - switchable NE/SW
>
> Ditto here. Or you might consider delta-loops. If you have high
> enough supports, these can be easy to tune and very effective.
The Delta Loops are good ideas, and with exception to my good friend
Bill, the Apex on a pair of 40 loops
is only about 40'. And you can vary the TO angle by rising and lowering
the apex. One word of warning. Most signals from EU come in at a 20-23
degree arrival angle. Delta loops have very low TO angles, and you may
find the "footprint" going right over Europe. I built one for 80, and
would have done better shouting out the
window for Eu. But, that sucker tore the band apart into the Middle
East, Asia, and JA. Try giving A61AJ one
call on 80 SSB, and having him come back to you, tell you you're 20 db
over the others, and ask what kind of antenna you're using.
Be glad to model any antenna for any band.
Also, a 1/2 wave vertical is a very good choice. About 66 feet tall, fed
at the bottom with a parallel LC
network ( make the capacitor out of RG8 ) for a perfect match.
73
Ed
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