Hi Chaps,
Just to clarify things.
Helical antennas come in two flavours that are described by the mode of operation. The helix may be operated in the broadside mode or in the axial mode both are refered to as helical antennas. Normally one would clarify the subject by refering to a "broadside helix " or an "axial mode helix" . One does not construct arrays of broadside halix antennas but axial mode halices are very common and for most part when axial mode helix antennas are used they are just refered to simply as helical antennas. If a broadside helix was chosen it would be specifically refered to as a broadside helix. Each of these helicals has quite different characteristics. Axial mode halices are characterised by "highish" gain and very wide bandwidth.
Generally it is understood what one is refering to when one talks about helicals. At HF a helical antenna is further clarified as a helical whip antenna
at VHF helical generally means axial mode helical.
Regards,
Jerry
