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A C1"'''I' and Dirtv - 1.5-.II"ter A ntenn" Jar the Paul Cook III, WA 7CSK
Longhou! ns
2943 N.E. 178th Street
Sea ttle, Washington 98155
The $4.98 Novice Special
There's no doubt about it, with the
sunspot cycle where it is now. 15 me ters is
the best band for the Novice who wants to
work the world. Openings to all conti nents
occur da ily, and flea po wered Novice stations
are picking off the rare DX like
shooting fish in a barrel. The word seems to
be getting out, and now more and more WN
callsigns arc heard on 1S. When the choice
DX moves in on freq uency, there are even a
few pileups - an occurcnce formerly reserved
fo r 20 meters. If you want to work
AL L of the DX with good consistency,
you're going to have to have a good signal.
Most Novices today run 75 watts into a
simple dipole ante nna, but if you want to be
" top dog" in the pileups, you'll just have to
do one better than the next guy. One way of
doing this is to increase your transmitter
po wer beyond the Novice lim it of 75 wa tts.
Ho wever, tha t jus t means big trouble with
the FCC, so a better thing to do is to put in
a better antenna. In this article I' m going to
show you how to build a beam antenna that
will beef up your signal so that you can
really "sock-it-to-tern" on 15.
T he antenna tha t I am going to describe is
called a phase d vertical array. It consists
basically to two 1/4 wave vertical antennas
with 1/4 wave radials placed 3/8 wavelength
apart. The antenna is fed with appropriate
match ing and phasing sections and has a gain
of about 6 db. This 6 db of signal improvement
is the same as if you changed your
transmitter power from 75 watts to 300
watts! The antenna is very cheap and easy to
build, and you might have all of the parts, so
then it may cost you nothing.
Th eory
Basically, the antenna consists of two
vertical ground pla ne antennas placed in
"phase" with each other. T his mean s that
the two ground planes are placed at a certain
Parts List:
200 ft. of wire
2-2x4 boards, about 1 2 ft. long
25 ft. of RG59/U coax ia l cable
50 ft. of RG58/U coaxial cable
E teet-teet t ape
Solder
4 -egg type insulators
distance apart so that the signals from both
antennas complement each other and produce
higher radiation in one direc tio n. This
works the same for receiving. In this way we
( I) reduce QRM to stations in other direct
ions because they don't hear us, (2) reduce
Q RM from sta tions in other directions
because we don't hear them, (3) increase our
signal strength in the desired direction, and
(4 ) inc rease the received signa l strength from
stations in the desired direction. This all
adds up to higher station flexibility and
efficiency.
Construction
To build the antenna you will need the
materials that are listed in the pa rts list. The
two boards can be mounted on the side o f a
roof, like my own installatio n, or mounted
on the ground. Before you erect the boards,
pound a nail in each end of both. Then
measure out I I feet of wire and connect it
to two egg insulators. Do this for both
boards, and be sure to solder. Next, take
fishline, rope, or what have you, and string
up the wires vertically o n the boards, tying
the insulators to the nails. Then erect the
boards. When you do this, be sure that both
boards arc vertical and 16-1 / 2 feet apart.
Feedline and Matching Section
Now you have constructed the antenna,
and it's time to piece together the ma tching
sect ion and feedline.
Take one II foot piece of RG59/U 7 5
ohm coax and splice it to an II foot piece of
RG58/U 52 ohm coax, as shown in Fig. 1a.
Do a neat, careful job and wrap the connection
well with electrical tape. If you have
some Krylon spray, use it on the connection
to do a completely weatherproof jo b.
Get II fee t of RG59/U and the R G 58/ U
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