A J-Pole antenna is a common first build. Most are built out of copper pipe and are rigid. A rigid J-Pole for 2m is a bit big to take portable so, I decided to see if a J-Pole would operate well made out of stranded wire. Wire would make the antenna flexible and easily coiled up.
The measurements for this antenna are the same as the rigid type. To calculate the length of the wire, I used M0UKD.com. It also has instructions for building a Slim Jim Antenna. This site is very informative.
Since the antenna is not rigid, I had Macarr Labs 3d print me some parts to form and hold the wire in place. Zip ties are used for strain relief. If this antenna performs well this will be redesigned.
First check with the analyzer was promising. The antenna is resonant around 144 Mhz. This was expected. Usually I cut a little long so wire does not have to be added while tuning.
The J-Pole roles up nicely. Even with the choke it does not take up much room. The coax may be shorten while tuning to make it more compact. Tuning and testing will be done in a future post.
- Using a LM317 Adjustable Regulator
- Basic Weather Station Using a D1 Mini Pro
- Single Lever Paddle For the uBITX
- uBITX 3.2″ Touch Screen
- Installing a uBITX in a Case.