Hardware Chat

Nothing magic about the VFA, a variant on mobile HF loaded whip.
The single wire feeder was an integral part of the antenna and would also have been radiating. Illustrates that very simple short antennas can still give plenty of contacts on HF.
Another version at http://www.hamuniverse.com/g3xovjoystick.html

73 Trevor M5AKA

I saw that - but there are not a lot people talking about actually using one at present. There is some fairy dust suggested - such as the coil section using a wooden former to dampen Q (I can believe that). Otherwise, as you say, it is what it is, with potential for high RF voltages.

I suspect the open wire feed may be a bit of a QRM magnet, so I am also looking to mess about about with 50/300 ohm feeders and baluns

I'm also having a go at designing a varicap/pin switched tuner and preamp/buffer to feed 50/75 coax or balanced 300, for location well away from noise, that can be located at the feed point on to the bottom for RX only applications. I might even try driving a 100 ohm pair in the Cat5 cable needed to tune and switch it. I suspect this thing may have some of the attributes of a loop (hi Q/ noise immunity) without the physical awkwardness and with omnidirectional attributes. We shall see. I bet there is a huge electrical storm the day it goes up..

Many fun hours of experimentation ahead this summer.