N1RIK'S 6 METER
MOXON
Editors note: Bill
is busy with converting this moxon into a 3 element moxon. We'll
post that info as soon as we get it.
My name is Bill, and the callsign is N1RIK. I have and still am
very impressed with your website here. I have since built a moxon for
6 meters, and one for 2 meters which I gave away to a local ham for
SSB.
I'm enclosing in this email pictures of my 6 meter Moxon. It looks much similar to WA0WOX's 6m moxon.
I
decided to build a PVC "U" frame out of 1/2" PVC. I opted out of using
an apoxy to hold the pvc together, and used a thin wrap of duct tape to
put on the ends of the pvc sections to twist into the pvc elbows and T
connectors for a tight fit.
On the driven element, I used 2
sheet rock screws to go through the pvc t connector and pvc arms for
extra strength, and to hold washers into place for the connections of
the RG-58 coax and the driven element.
3 inches below the
connection for driven element on the coax, I installed a Palomar BA-58
1:1 current balun bead set so I wouldn't have to add extra coaxial loss.
From the pvc T connector, I added a
2 ft. section of 1/2" pvc to hose clamp to my fabricated PVC mast. I
overlapped 1 ft. of the 2 ft. section, which keeps the Moxon 1 ft.
above the PVC mast.
I used zip ties to keep the elements onto
the PVC frame, and wrapped coaxial connections to the driven element
with silicon self-sealing wrap and Scotch 33 tape.
For element
materials, I used Radio Shack #8 gauge aluminum ground wire. Radio
Shack has discontinued this project, so I had to buy it on ebay.
PVC Mast:
My
19 foot PVC mast is made from a 10 ft. section of 2" Sch. 40 and a 10
ft. section of 1-1/2" Sch. 40, which overlap by 1 foot, and is held
together with 4 sheet rock screws. I currently have this mast bungy
corded to my porch up to 5 feet up, and seems pretty stable. At this
height, the antenna is a full wavelength above the ground.
Tuning:
I
built this antenna to specs on the software, however once I started
playing with it, I noticed my SWR @ 50.2 was 1.6:1. and 1:1 @ 48.2
MHz. I started trimming the antenna with my analyzer and now have it
1.1:1 @ 50.2 MHz. Here's the new dimensions :
A = 85.25 in B = 10.25 in C = 5.25 in D = 15.5 in E = 31.0 in
The
overall length of the driven element is 105.75 in and the reflector is
116.25, which is a 9% difference. I was thinking about shorting the
reflector, however the performance seems to be to spec.
Performance: I
was checking the F/B ratio on a station about 200 miles away in South
Carolina who was running about 1KW. He was S8 to 9 with me pointed on
him, however an S4 with my backside to him. That's a 4 S-unit
difference, and at 6 db per S-Unit, aprox. 24 db F/B ratio, which is
around spec.
During normal conditions via groundwave, I can talk about 200 - 250 miles out with my antenna 20 ft.
AGL.
SWR:
48.5 MHz - 2.0 49.0 MHz - 1.5 49.5 MHz - 1.2 50.0 MHz - 1.1 50.5 MHz - 1.1 51.0 MHz - 1.2 51.5 MHz - 1.3 52.0 MHz - 1.4 52.5 MHz - 1.5 53.0 MHz - 1.6 53.5 MHz - 1.7 54.0 MHz - 1.8 54.5 MHz - 2.0
My
2:1 SWR Bandwidth is greater than 6 MHz and 1.5:1 bandwidth is greater
than 3.5 MHz. This is antenna is very wide banded and covers the whole
6 meter band. Also it has a 2:1 bandwidth of 11 MHz from 158 - 169
MHz, and 162 - 164 MHz is flat 1:1.
I plan to rebuild this
antenna into a 3 element Moxon for some extra gain. I also may replace
my feedline, which is 29 ft. of RG-58.
From my home in Southern
Pines (Vass), NC (FM05), I can check into nets in Virgina and South
Carolina with actual signal readings on my S-Meter. The materials cost
me less than $10 for the antenna and $10 for the 19 foot mast.
Thank you for the website. I'm so glad I built this antenna
versuses paying about $100 for PAR's Stressed Moxon
73 ~ Bill, N1RIK
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