10m Band J-Pole Antenna

 Because the performance of my long wire antenna seemed to be lacking on the 10m band, I decided to build a J-Pole. I have built these in the past and used them on the free band frequencies to great effect. Quite often I had the opportunity to build and compare several antennas and this one always outperformed the others. Previously, I had erected one on the side of the house, but these antennas are very tall and are subject to being destroyed in a bad storm as I found out eventually.

So this time I have a plan. The antenna will be erected just above ground level with the bulk of the mast being fed up the trunk and through the inside of our palm tree. This will offer great protection from the elements and also hide most of the antenna from prying eyes.

(Practically invisible - except for the bit at the top poking out!)

I used an online calculator for the lengths and proceeded with the build. The bottom matching section was crafted from twin feeder since the gap between conductors is not critical. The top radiator section is just a piece of 1.5mm2 wire. I found that the feed point had to be moved considerably higher than the calculator suggested, but once the point was found everything was fine. The bandwidth for this type of antenna is usually quite narrow. The SWR was on average 1.5 between 27.5 and 29 MHz. With the ATU in the rig, this can be stretched considerably. The trusty Nano-VNA became invaluable once again. What a great little piece of kit this has been! The screenshots can be seen below:

(Scan from 20 to 30 Mhz)

(Scan from 100 to 150 Mhz. Surprisingly tuning into the 2m band)

Below you can see the plots produced by MMANA-GAL

When comparing the antenna to my long wire I found the reception to be a lot clearer without as much background noise. However the long wire takes some beating for all-round performance and multiband use. This antenna is excellent on its design frequency of 27 to 28 Mhz.