2 meter quarter wave antenna


This is the first transceiving antenna I've ever built. It is perhaps the simplest 2 meter quarter wave design.
Element sizes are based on the formula:

length of elements in feet = 234 ÷ freq

Using 146 MHz as midway in the 2 meter band:

234 ÷ 146 = 1.6 ft

1.6 ft x 12 in/ft = 19.23" for main vertical element & for each ground radial

1/16" welding rod for elements

horizontal elements: rod ends curled with needlenose to allow fastening beneath machine screws:
rodcurl

vertical element soldered to SO-239:
solderrod

4 horizontal radials fastened with machine screws & lock washers:
4horiz

completed quarter wave 2 meter antenna located barely above patio, next to I-Max 2000 10 meter flag pole:
qtr+iMax

short PVC mast, painted, capped, siliconed:
close


RG-213 coax connects the tranceiver to the SO-239 on the antenna.
The SWR is 1.35:1 across 2 meters.

Although this design was not supposed to cover 70 cm, the resonance in that band is even better: 1.1:1

The dual band 5w 144/440 BaoFeng UV5RA's we use get good signal & audio reports. This antenna allows me to reach several repeaters that I could not while using a 7" or 15" rubber duck indoors.
Note: Both the BaoFeng UV5RA's we own have been tested for spectral purity and are Part 97 compliant.
We also have a pair of BTech 5w UV-5X3's, and both of our tri-band 144/440/220 units tested as fully compliant with no significant spurious emissions. The UV-5X3's are also Part 15 approved.

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There is 8' additional PVC mast below the patio roof line, recessed in the corner post. In emergencies the antenna could easily be raised for better performance.


updated 16 February 2018   © 1932-2018 Derrick Garbell    All Rights Reserved    Radio page