[Elecraft] Antennas for Field Day

[Ron D' Eau Claire]

> I am planning new antennas for Field Day and could use some advice on what
> configuration will give the best-cost performance ratio....
> Jeff Burns
> AD9T

At 30 feet up, the 20 meter dipole is showing about 10 dB of directivity.
That is, signal off the 'ends' is about 10 dB below the main lobe off of the
sides. "Crossed dipoles" on that band might be an advantage.

You can do away with  the pattern altogether by using something vertically
polarized, but that would reduce your signal in all directions by 6 dB - the
'ground reflection' gain you are enjoying by having a horizontal antenna up
at 30 feet on 14 MHz. I'd stay horizontal at that height and keep the gain.

On 40 and 80 the situation is a lot different. At 30 feet up, the horizontal
is no better than a vertical at elevations of 20 to 30 degrees above the
horizon. You are too low to get any advantage from the ground reflection
except virtually straight up. The near-vertical radiation will help with
close in contacts (out to a few hundred miles), but won't be much help
beyond that.

On 40 and 80, I'd take a hard look at something vertically polarized -
probably a loop to avoid the issues of radials, counterpoises, etc., - and
possibly something that is somewhat directional such as a phased array. A
lot of that depends upon how many bands you want to cover. Arrays can get
tricky as you try to hop from band to band. It's not just a matter of being
able to 'load up' but also what happens to their patterns as you change
bands.

Field day is about the only contest that I've been very active with. In the
club efforts I have seen, there is always a lively discussion between going
for 'high gain and high directivity' to kill QRM and 'reach out' and going
for low directivity that doesn't require twiddling with the beam all the
time. Personally, I like something that is not too directive.

Ron AC7AC