Firstly, before make an micro-exped, there are some major factors to set up:
- How many time will I be active ?
it's a fact ! if you have only some hours free to activate your lighthouse or your isle, you'll not have to spend so much time by putting the antenna(s) ! it means that for a less than 6 hours on radio, simple ground plane or verticale or horizontal dipole or G5RV will do the job. take care about guy roppes...you need many time to put guy wires. Try to find a system that can be erected without guys.
- Where will I be able to put antenna ? what place available ?
a wire dipole need some free space. A ground plane with radials need also a nice set up with good electric ground and more than 5 meters plan land to put radials as much horizontal as possible.
a verticale dipole will need very short place and like also the sea water to provide low angle pattern. This antenna on a normal ground will not outperform a horizontal dipole.
A Yagi/Quad will need a good mast at more than 1/2 wave of height to have a minimum of results. these antennas need guy wires and place to put up/down. Using these horizontal antennas near salt water is a lack of time and efforts...We prefer to put some verticales as close to the sea. If you can't put a verticale at less than 2 waves lenght of the sea water, verticale will not outperform the horizontale at 1 wave lenght high. Put a verticale means that you'll do the best to put it as close as possible of the salt water. You can use also more radials on the GP to help the lack of electric ground.
- What bands will I be QRV ?
Sure ! if you need to be multiband, you need or a multiband auto switching antennas (G5RV, FD4,multiband dipôles,...) when free time is limited. Anyway, monoband antennas still have the best results and if you look for gain, good angle pattern, some monobands with different coaxials will do a better work.
it's also a good solution to build a manual band switch antenna. An horizontal dipole or a wire ground plane with some "fast-on" clips is a good solution and you'll need only 1 minute to change band. no need of tuners, etc...
GROUND PLANE MONOBAND 20m with 8 radials 1/8wave length
More radials or most close to the sea = better results on DX stations
A ground plane monoband 40m (10m high) with 16 radials 1/8 wave on the ground (during TK1INT)
Some "fast-on" clips are on the radiator wire, that permit to transmit on 10-12-15-17-20 or 40m. Even if you don't put some other tuned radials, it work perfectly. I usually use 8 radials of 5.20 meters long (for 10-20-40m) + 4 radials of 4m (17m band) + 4 radials of 3.35m (15m band) but more you'll put radials, more the antenna will have a low angle pattern.
During a 1 day exped, putting radials need some minutes to put on the grass..it's not in my mind to put 164 radials !
This is a verticale pola MOXON 2elts, made with a 10m glass fiber mast and 2 glass fibers mast of 2m70 at 1m high and at 8m high. it provide a good front/back ratio, a low angle pattern when the antenna is close to the sea. I made some tests on the beach anyway no good propagation...I plan to put a vert. dipole and a switch coaxial to make some tests "moxon 2 verticale vs vertical dipole"