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MINI
HORIZONTAL "V" 2 ELEMENT "HAMSTICK" 20M BEAM. by Russ
Wilson, VE6VK
Material
Required: 4ea 20M "Hamsticks" 1 inch diameter boom 4
ft 6 inches long. 1 aluminuum mounting bracket driven
element. 1 aluminum mounting bracket reflector. 4 insulated CB
mounting kits 3/8" by 24 TPI (2 can be un-insulated for
reflector. Wire for hairpin match. 14 gauge electrical wire with
insulation removed. Coaxial balun 12.5 ft RG58 wound on a 1-1/4
inch white PVC 8 inches long. Bolts, nuts, lock washers for
mounting.
CONSTRUCTION: Two
aluminum brackets are made out of scrap aluminum 1/16 inch thick or
a little heavier if desired. The brackets are bent into shape as per
the photographs to allow element kits to be mounted so the elements
are at 90 degrees from one another. At 15 ft off the ground,
measurements were made of the Driven element using an electrical 1/2
wave length of RG58 as a 1:1 transformer. Using the antenna analyzer
from the ground the following measurements were noted. Impedance
25 ohms SWR 2:1 The antenna was resonated to 14250
Khz.
A hairpin match was made using #14 gauge electrical wire
with insulation removed. Two lengths 18 inches long are required.
(See Arrl Antenna Book for more on hairpin matching) The two
wires have solder lugs placed on them at one end. These ends are
connected to each mounting kit terminal for the Driven Element. The
wires are spaced 1-7/8 inches from each other and are arranged so
they are approximately 1 inch above the boom. See photographs for
details below. A couple of wood or plastic spacers are used to
keep the wires separated. Also a piece of 3/8 inch thick plastic is
mounted on the boom, 2 holes drilled for the wires to pass through
for extra support. After the hairpin is mounted and a temporary
shorting bar placed across the hairpin, the antenna is placed in its
original position and further readings taken, adjusting the sliding
short across the hairpin, until the impedance of 50 ohms is reached.
A little juggling of the whips to bring the driven element back to
14250 Khz is necessary. After a few minutes of testing and
adjustment of the hairpin short and the whips, the resonant
frequency of 14250 Khz is reached and the impedance reads 50 ohms.
The wire short on the hairpin can be permanently
soldered.
Measure the length of the whip on the driven
element, multiply this by 6% and add this to the length of each
driven element whip. In my case it was 38.5 inches. 2.3 inches was
added to each reflector whip. The boom length was experimented with
and the length shown seemed to be optimum for the short boom. The
reason for the resonant frequency chosen was my own personal
preference as I do quite a lot of operating for IOTA 14260. If you
wish to operate CW or any other preferred frequency you can choose
by figuring out the frequency response of the beam is approximately
200Khz. The photographs should assist in figuring out the brackets
etc. The actual measurements from tip of whip of each half element
to boom. Driven 1/2 element = 86.625 inches (220.0
Cm) Reflector 1/2 element = 91.75 inches (233.0
Cm) This is using the regular Lakeview
Hamsticks. The PHF type are much better and you do not have to
readjust or mark the whips.
I
worked XZ7A on CW with the beam and 80 watts, so apparently it
works. A frequency run and measured SWR is as
follows:
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14100
2.5:1 14130
1.5:1 14140
1.3:1 14150
1.2:1 14165
1:1 14202
1:1 14250
1:1 14300 1.1:1 14350
1.4:1
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 The finished product!
 The not so "Ugly"
balun
 Note the 90 degree angle between element
attachment mounts and the 45 degree angle to the boom of the
driven and reflector elements!

 Pictures
above showing driven element detail with hairpin match attached
and insulators mounted on boom
Many
thanks to Russ, VE6VK for allowing us to share his project with
all! Russ not only is a fine antenna builder, ask him how to
catch a fish! Email Russ here for
questions
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