J-Pole Vertical Antenna -VHF 70Mhz (4m) Amateur Band



J-Pole Vertical Antenna -VHF 70Mhz (4m) Amateur Band

J-Pole Vertical Antenna -VHF 70Mhz (4m) Amateur Band

£150.00 — £255.00

Product Code – 70-JPOLE

A J-Pole Antenna for the 70Mhz (4m) Amateur band. The ‘J-Pole’ Antenna consists of a half wave vertical radiator and an adjacent quarter wave tuning stub which forms the classic ‘J Shape’. The J-Pole has an added advantage that tuning can be varied over a fairly wide frequency range by moving the feed-point location up or down. This also gives the user finer control over the impedance and match. The antenna is end fed and has an omni-directional radiation pattern and requires no ground plane or radials.

J-Poles should include a 1 to 1 ‘Choke Balun’ close to the feed-point, which prevents feed-line radiation. A simple and cost effective solution is to wind a small length of coaxial cable around a former as shown in the images. Vortex can also supply this if required in commercial grade ®Westflex 103 Coaxial Cable . A Vortex Antenna Systems premiumFerrite Core 3kw Choke Balun (Sealed to IP67 rating) is also available as an optional extra.

No Knowledge of Antennas? Our 70Mhz antenna is pre-tuned from the factory and all set-up measurements are included. However the system is fully adjustable should the user require to finely tune the system for their own requirements. We include a full set-up instruction sheet with each antenna.

All Vortex Antenna Systems J-Poles use heavy duty components including our h/duty element clamps with M10 Stainless Steel Allen Head Bolts and hardware as also used in our lower frequency base antennas. The main element section of the antenna is genuine VORTEX 16mm 6082-T6 or *AA6082-T6 Aluminium which telescopes down using 2 sections, with 12mm tube for the matching section. The feed from the SO239 socket is twin 6mm 762 strand low-loss oxygen free copper flex to minimise losses.

® WH Westlake Electronics
Antenna shown – 2m J-Pole for illustration purposes

See info below for mechanical and electrical details

  J-Pole Vertical Antenna – VHF 70Mhz (4m) Amateur

Band(s):  6m (50MHz) Amateur
Element Material:  6082-T6/*AA6082-T6
Optional Mounting Kit:  Genuine ‘Vortex’ Stainless Steel U-Bolts and Saddle Clamps
Gain:   2.9dbi
Feed:   Coax via SO239 socket
Matching:   None – Direct Twin Line to Feedpoint. Twin Line is positioned for best match
Rating:   3.5kw
Element Clamps:   Stauff (Germany) – heavy duty polyamide series
Antenna Weight:   3kg
SO239 to Antenna Feed:   6mm 762 Strand Oxygen Free Multistanded Copper Twin Conductors
Hardware:   304/316 stainless steel

*If available