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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