Product number : 11-J-Pole
price : 169 euroGain: 2,4 dBI Gain: @ 10m height: 4,23 dBI SWR bandwidth: 1300 Khz Max Power: >10Kw Lenght: 8,0 meter Weight: 5 Kg Mast attachment: < 50mm Element diameter: 40 to 16 mm
The J-pole antenna is a mechanical 3/4 wave vertical antenna. With the main radiation coming from the top section.
In essence the J-pole is a halve wave radiator with a quarter wave matching stub underneath the antenna.
The matching stub illuminates the need for a coil (loss) and can handle immense high powers.
There are several different variants of J-pole antennas. ALL have a maximum gain of 2,4 dBI. (do not be mislead with figures higher as 2,4 dBI !)
Amongst those variety of J-poles you will find out there are difference in height and SWR bandwidth.
The HPSD J-Pole has the height advantage. It is slightly higher compared to those others.
With the additional length it is logical the “horizon” has moved further away providing a wider range of coverage.
For the above reasons the HPSD J-pole can be considered to be one of the best vertical antennas for 27 MHz communication.
The J-pole comes of course with a RG213UBX RFCHOKE (2Kw)
The “real” antenna elevation plot.
Real SWR Antenna PLOT
(click to enlarge)
The J-Pole made by HPSD, as ALL HPSD antennas is a heavy duty version, and will last a life time !
PDF DOWLOAD HPSD J-POLE HOW TO MAKE ONE IN DUTCH : J Pole versie 1.01