There is another form of long wire antenna which provides uni-directional coverage and is easy to build.
From the transmitter or transceiver, you go to an antenna tuner via coaxial cable. The tuner is placed at the base of the antenna, not at your operating position.
From the tuner's single ended output comes a wire that first goes STRAIGHT UP for about ONE WAVELENGTH at 50 mHz...
Then the wire is bent and slopes VERY GENTLY in the direction of the desired coverage, You want the wire to extend itself for no less than 5 wavelengths, although shorter versions work quite well too, but are not SO DIRECTIONAL.
The wire SLOPES until it ends at a height of about ONE TO TWO METERS ABOVE GROUND.... There you tie it to a small mast... THEN.... tied to this small mast you need to place no less than 3, and much better 5 one quarter wavelength radials , that act as a counterpoise... The radials will kindly help to hold the small mast in a vertical position... You can use very small insulators for the radials, or tie them with dacron or nylon lines ( I prefer to use dacron lines similar to those used for sailboats ).
REMEMBER to aim your antenna to SLOPE in the DIRECTION that you want to communicate with....
It shows a gain of no less than 5 to 6 dB over a horizontal dipole when the wire length is about 30 to 40 meters....
The antenna seems to work also on 10 meters , with the appropriate tuner, and I have tested it on 2 meters too, but have yet to do some really good comparative tests against my "standard" 5 element portable yagi.
This VERTICAL 1 wavelength + HORIZONTAL SLOPING 5 to 7 wavelength antenna + RADIALS, can be taken on a reel, and the wire can be really light... a lot easier to transport than a YAGI or a QUAD, and certainly a lot easier to build and to put in place. YES... YOU ARE RIGHT... I always USE A TREE ( when available) to hold the VERTICAL PART OF IT !!!
Hope this helps those in need of a very simple, low cost, unidirectional field antenna for VHF use
Arnie Coro CO2KK
Host of Dxers Unlimited
Radio Havana Cuba
e-mail : firstname.lastname@example.org
Radio Havana Cuba
Po Box 6240