On Fri, 11 Jan 2002 17:40:38 -0800 (PST) Michael Watts <wy6k@yahoo.com>
writes:
> If a lower antenna is better only in some small percentage of cases,
> then it's not wise to advise
> a one antenna guy to put the antenna lower. There seems to be
> substantial agreement that higher
> antennas perform better a larger percentage of the time than lower
> ones. Is this not true? If
> you had only one antenna, would you put it lower or higher?
If you have only one antenna you should definitely put it
lower.
If you take a quick look at antenna patterns, you will see that
the higher the antenna, the narrower the lobe.
A low antenna (50' 20M) is 3 db down from a high antenna
(90' 20) at the lowest angles.
But, the high antenna will have a 30 dB null in the middle of prime
arrival angles (90' 20M, 22 degrees). You will get KILLED much
of the time.
Which would you rather have, -3dB or -30dB?
If you have only one antenna it should be less than:
50' on 10M
70' on 15M
90' on 20M
50' for a tribander during sunspot maxima. Minima 70'.
Now some of this depends on what type of operating you do.
Contesters have to work EVERYBODY, ALL THE TIME (ALL the
angles).
DX'ers are happiest when they are the first to get through
on some difficult propagation path (The lowest angles).
The best answer is to download YTAD and figure it out for
yourself.
Dave Hachadorian, K6LL
Yuma, AZ
K6LL@juno.com
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