As the 4 metre band is so quiet, it was decided that this antenna should be designed with forward gain as a priority over front to rear. However, this antenna still achieves a very useful 18 plus dB. F/R. The band is also very narrow, so any trading of gain to obtain bandwidth was unnecessary. With a gain of 15.5 dBi at 12 metres (8.6dBi free space), this antenna is a great little performer

Specifications:-
- Frequency range : 70-70.5 Mhz
- Gain, typical : 8.73 dBi
- Front to rear, typical : 18.5 dB
- Feed impedance : 50 Ohms
- Connector : 2 x 4mm threaded terminals
- Power handling : 1.5 Kw
- Matching : Hairpin
- Boom length/diameter : 1.48 metres / 44 mm
- Element diameters : 13 & 9.5 mm
- Weight : 3.1 KG

The HFV2 is a helical antenna resonant on the 40 metre amateur band. Designed with the ever decreasing antenna space available for amateurs in mind, it will provide surprisingly good DX performance from an antenna only 5.6 metres (18' 4") long.

Construction
Construction is of polyurethane coated fibreglass tubing (25mm & 19mm dia.) with heavily plated brass joining components, topped with a tapered stainless steel whip. The helix is encased in foam within the tubing, providing maximum protection. This antenna is extremely robust, and capable of withstanding the severest of weather conditions, including marine.
Mounting
As with all ground mounted vertical antennas, a good ground radial system will produce the most efficient radiation, however good DX has been achieved with simple counterpoise systems where good soil conditions are present, a small ground system is better than no system at all. If you wish to mount the antenna in a lofted position, radials will be necessary, we advise three, 66 ft. lengths of wire, evenly spaced, radiating from the base of the antenna. If mast mounting, the guy wires can be used as radials. Complete with mounting brackets &"V" bolts etc. Termination is an SO239 socket.
With it's ability to be broken down into three section, the two longest being 2.3 metres (about 8 feet), the HFV1 is easily transported, making it is also ideal for portable operation.
Weight - 3.5 Kg. Including mounting hardware.
Gain
We do not quote any gain figures for the HFV1- II, as performance is dependent to a great deal on it's mounting conditions, and subsequent ground losses, see above. The low angle of radiation achieved by vertical polarisation will show a marked increase in DX performance over horizontally mounted wire dipole type aerials. The technicalities of ground losses and radiation angles are far too complex to go into here, we recommend referring to any of the numerous amateur radio antenna handbooks.