First Attempt With 20-Meter Phased Verticals
July 15, 2006 Genesee Mountain
*see details below photo*
Genesee Mountain west of Denver, Colorado. 8,100 feet altitude
Yesterday, I completed a new antenna project. It is a phased,
two-element, halfwave vertical for 20 meters. Since I began operating
QRP four years ago, I have wanted to try some gain antennas. The
34-foot, 22-ga. wires are held aloft by a pair of MFJ fiberglass poles
and are separated by 35 feet (one-half wavelength). They are kept
vertical by PVC bases. The phasing lines are half-wave RG-8X coax
and measure 28 feet, four-and-a-half inches (allowing for velocity
factor). They attach to the back of the radio by a coax "tee", and to
homebrew matching units at each antenna's base. How well does it
work?
This evening I drove 20 minutes from home and set up in a mountain
park at 8,100 feet. It has a good, low horizon in all directions. The
antenna is supposed to have a 60-degree beamwidth in two directions,
and 4dB of gain compared to a single antenna. I wanted to aim the pair
toward the South Pacific and Europe, so I settled for a heading of
235/055 degrees. My first contact was CU7X, a DXpedition to
Faial Island in the Azores. The very next QSO was with F5PFP, in
France. In order to change directions, I lift the antennas one at
a time and
move them. A thin 35-foot rope is tied between them to keep the spacing
accurate. I verified the new setting with a handheld GPS. I should
note: The antenna was maximized for 14.060, but it seems to work fine
for the phone portion where I operated. Credit for the antenna design
goes to Paul Stroud, AA4XX from his Adventure Radio Society article.
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All contacts were made with 5 watts SSB using an FT-817 and a $20 computer headset.
For future reference, the A index was 6, the Kp was 1 and the Solar Flux was 70. Nice and quiet.
Here is a log of tonight's QSOs and the compass headings of the antenna. (I operated from 0100-0500Z, July 16.)
Heading: 235/055 degrees true
CU7X Azores
F5PFP France
KU6T California
VA3DZ Ontario
AC0CX Western Nebraska
Heading: 313/133 degrees
PY5/SP7VC Brazil
K4PPK Florida
K4RAR Florida
KH6KW Hawaii
VE6AO Alberta
Heading: 245/65 degrees
ZL1LU North Island, New Zealand [He was a bearing of 230
degrees I discovered later.] (He had rough copy on me, but we made it.)
K6SAD California
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I heard quite a few DX stations, but never broke the big pileups:
F0/F6CTL; LA/SV2KBS; F4FAZ; EA1TU; VK2AEV; etc. I could have stayed out
later, because the band was still open, but the park closes at 11:00
p.m. (0500Z).
My next project? Three half-wave verticals phased with ladderline and end-fed at the center antenna.
