"P.P.S. You might want to consider a clover-leaf aerial. That enables what they call 'circular polarity' transmission, which is really useful for drones when the transmitting aerial is performing contortions in the air. For boats, a vertical aerial pumping out vertically-polarised waves may suffer from 'bounce' off the water surface, which turns the reflected waves horizontal. But these are very cheap anyway, and can be experimented with"
Yes I'd noticed the clover leaf. Not the most efficient antenna but agree it's a nice compact design. Agreed the reflections can cause some polarisation distortion.
A vertical antenna (properly earthed) also produces a ground wave propagation which travels especially well over water, but admittedly not so long range at 5.8Gigs. Works best at lower frequencies where the absorbtion rate in water is lower. Those operating in salt water lakes on the coast are better off in this respect than us fresh water sailors!
So I was thinking of using antenna diversity, one vertical and one horizontal.
Just like most 2.4Gig TX/RX sets already do. A vertical stub antenna at the top of the TX case and a horizontal antenna in the handle usually.
Of course if you hold the TX flat on it's back then you are relying on the horizontal antenna component!! At the RX end two 12,5cm wires, one vertical, one horizontal is the counter part.
Works well in my Sea Scout.
For 5.8 Gigs the wavelength is a little less than half that at 5.1688cm so the clover leaf is a reasonable compromise.
Didn't spend my professional life working on all types of radio systems, from VLF/HF through personal mobile and cellular systems up to full COMMS suites with datalinks on naval vessels for nuffink. Some of it stuck! 😉
Having successfully hijacked Ken's thread (Sorry Ken😭) I guess we should continue this discussion (if required) in a new thread! Cheers, Doug 😎