"Question, why not put the 40 at 135 ft? At that height it would be 1
wavelength high and perform even better!! I have my upper 40M beam at
134
ft! Check out my web site: http://www.erols.com/n3rr "
73
Bill, N3RR
...................
Bill (et. al.),
Since you have stacked 40M beams, I'm sure you have found times
when your LOW beam is better than the high one. They will become
even more prevalent as the sunspots increase.
When W3LPL was at his old QTH, he had a 3L40 at 130 ft. It didn't
take him long to add another LOWER 2L40 beam at 65 ft. to improve
his competitiveness during the afternoon / early evening openings
which tend to peak at 20 to 30 degrees (or so) to Europe and Africa.
When N4ZC had only one 40M beam, a 4L KLM at 130 ft, he used
to curse all of the guys with lower "shortie forties" who would beat
him out consistently before sunset. He now has a LOW beam to
solve that problem.
IMHO, 80 to 100 ft is optimum for the evening openings.
The HIGH 40M beams (150 to 200 ft) pay off during the early
morning hours and on the skew path (SSW) to SE Asia
around sunrise.
After sunrise, the JA's are easily worked with 80 to 100 ft high
antennas, peaking about 30 minutes past sunrise and sometimes
lasting until 3 hours past sunrise. ( I once worked V85 3 hours
past my sunrise, with a good 559 signal, on my 2L40 at 95 ft. )
My first 300 countries on 40M were worked with rotary dipoles
at 80 ft. Since adding fixed wire beams, and later a CC 2L40
at 95 ft., I have worked all countries except A5, BS7H, BV9P,
and P5 on 40 meters.
Starting from scratch, I would recommend stacked 2L40's at
160 / 80 ft. as possibly the most cost effective approach for
gain and flexibility. These heights give the maximum stacking
gain for 2L40's and can be implemented with Rohn 45 tower
guyed every 40 ft. An upper / lower / both switch box is desirable.
If F/B is important to you, then 3 elements will provide the
desired pattern but at considerably higher antenna, rotor,
and tower costs.
de Tom N4KG
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