Halfewave Coax-cable Antenna (J-Antenna) according DJ8EI and DL5PCIn CQDL 2014/06 was an article by Hans, DJ8EI/PA8EI and Helmut, DL5PC about building a L/2-Coaxialcable antenna.
Since the construction is easy to do i decided to use our last (tech)talk meeting at our local RadioClub M21 to build a version for 2m.
The design is a J-Antenna build completely with coax-cable.
So i brought 7m RG58CU, BNC crimp-connectors and one BNC T-connector in.
Target was to get the antenna resonant at 144.800MHz since main usage is for APRS.
Since there is an calculator for the dimensions vailable i cutted the cable into pieces according the instruction and crimped the BNC connectors on. The radiator i kept a bit longer to be on the save side.
Finally a small rope was attached to the end of the radiator to be able to put the antenna on the ceiling for adjustment.
|Measuring and adjusting the antenna|
After cutting some small pieces off the radiator we reached nearly 144.800MHz.
|Resonance on 144.791MHz|
ConclusionThe Antenna is easy to build with minimum of costs and easy to adjust.
Building up and adjustment took ~30min overall.
|Antenna with Cable|
|5m RG58 and Halfewave J-Antenna for 144.800MHz|
|T-Connector and stub|
73' de Gerald
- dk7xe -
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