Home made UHF Yagi Antennas
RE-A430Y10
By Guy, de ON6MU
Optimized 10-element UHF Yagi Antenna
Horizontal
stacking distance: 1075 mm
Vertical stacking distance: 933 mm
The elements diameter
of the antenna may vary between 5...10mm and the dipole diameter
may
vary between 8...12mm (12mm recommended) without the need of
changing anything to the length or spacing.
All elements except the dipole are electrically connected to the
boom and may be mounted on top or through it.
The thickness/diameter of the boom may vary between 10...17mm.
Bazooka tube (RF choke to prevent rf wave currents): not
critical, as long as it fits the coax snugly; examples: 15cm long
10mm diameter (for Aircel etc.), 15cm long 15mm diameter (for
H100, Aircom+ etc.). Or you can use a few ferrite beads placed
over the coax directly behind the driver instead.
Use a piece of isolator type boom (plastic tube, wood,
fiberglass) of +/- 40cm if you mount the antenna vertical to
prevent distorion of the radiation pattern.
The ideal SWR can vary a bit if the elements are isolated, raised
from the boom or do to construction. A bit of experimentation
with the driver length can solve this easily.
Note: the antenna can also be tuned
between approx. 428...446MHz by adjusting the driver
Images of the
70cm Yagi antenna,
How Greg
SP5LGN made it
Click to enlarge
Thanks Greg for the photo's!
Optimized 6-element UHF Yagi Antenna RE-A430Y6
The elements diameter
of the antenna may vary between 5...10mm and the dipole diameter
may
vary between 8...12mm (12mm recommended) without the need of
changing anything to the length or spacing.
All elements except the dipole are electrically connected to the
boom and may be mounted on top or through it.
The thickness/diameter of the boom may vary between 10...17mm.
Use an isolator type boom (plastic tube, wood, fiberglass) if you
mount the antenna vertical to prevent distorion of the radiation
pattern.
Pictures and details of
the optimized UHF Yagi antenna
430 Mc to 440 Mhz (420 Mc to 450 Mc @ 1:2 SWR)
Michel
F1SRC and how he made it:
http://f1src.free.fr/antenne/yagi/yagi_6el_70cm.htm
How Greg SP5LGN made it
Click to enlarge
Thanks Greg.
How Geert
ON3GVG made the antenna:
Note from Geert: he made the driver a few mm smaller to
obtain an obtimum SWR in the band segment.
Thanks Geert!
Optimized 4-Element UHF Yagi antenna RE-A430Y4
de ON6MU
Check this out:
The elements diameter
of the antenna may vary between 5...10mm and the dipole diameter
may
vary between 8...14mm (12mm recommended) without the need of
changing anything to the length or spacing.
All elements except the dipole are electrically connected to the
boom and may be mounted on top or through it.
The thickness/diameter of the boom may vary between 10...17mm.
The ideal SWR can
vary a bit if the elements are isolated, raised from the boom or
do to construction. A bit of experimentation with the driver
length can solve this easily.
Bazooka (RF choke): you can also use a few ferrite beads placed
over the coax directly behind the driver instead.
Image of the 70cm
Yagi antenna,
How dr Sasa Vasiljevic made it
Thanks Sasa!
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