An alternative to the 6M7JHV antenna for 6m / 50MHz
Design wish list
OK, so what would we consider the ideal characteristics of a 6m antenna
design to be that would make the effort of swapping out the 6M7JHVs worthwhile? Let's dream for a bit...
Compact design is essential. Living as we do in the UK with small gardens, close neighbours and aggressive local authority planning departments, any 6M7JHV replacements need to be around the same boom length.
Reduced secondary lobes will held reduce noise in the receiver. We live in very electrically noisy town locations and it is that local noise that effectively limits what can be heard. Any antenna that holds the possibility to reduce noise will be a big winner with us!
Low Q would be a major boon after using the 6M7JHV. The 6M7JHV is a hi-Q design and detunes very easily in the face of close by objects. This has been so bad at G3WOS that they actually resonate below the bottom of the band. Many comments have been heard about rain detuning as well.
Increased bandwidth will be a massive benefit if it makes possible the working of terrestrial DX around 50.110Mhz and JT65a EME QSOs above 50.200Mhz with low SWR.
Simple matching as it would be really great if we could get rid of the T-matching as used on the 6M7JHV. If we could get a design with a near 50 Ω impedance that would be great - one less thing to overheat and fail.
Easy to make as we want a design that can be made on the kitchen table with easily available tools.
Low cost goes hand in hand with making antennas at home rather than buying - possibly importing - very expensive commercial models.
Easy to repair to ensure that can be repaired easily and cheaply if problems occur such as wind damage. The cost of replacing 6M7JHV T-match elements is excruciatingly high for us Brits.
Reduced sensitivity to static rain is some times troublesome and it would be good to use a design that would be less sensitive if that would be possible.
British design would be a great as well when the commercial amateur radio market is dominated by US and Japanese designs.
Aesthetically beautiful - well OK maybe not for my neighbours.
In 2010, there is probably only one design that comes anywhere near matching this wish list - G0KSC's LFA2 designs, so we decided to ask Justin to design us an antenna and we would build a to just see how they performed.