[TowerTalk] Re: Can takeoff angle be too low?
Dick pechie - KB1H
rpechie@snet.net
Mon, 18 Dec 2000 09:01:18 -0500
Here at KB1H we have a stack of Hy-Gain 105CAs. 84'/65'/45'. The top two
rotate on the same mast and the bottom antenna is fixed on Europe. Using
a WX0B Stackbox we can pick any single antenna, combination of any two,
or all three. Usually we run the complete stack when running Europe but
during non-contest times I play around. Many times the lowest antenna
alone is the best antenna to Europe at midday. When you hear the
tri-bander stations doing well then you can almost always predict the
lower antenna is the antenna of choice.
With almost 25dB of terrain gain towards Europe I suspect the usual
poorer performance of the top antenna can be contributed to this gain
and the installed height. I actually stopped my 20M tower at 90' because
analysis said 120' was not as good!
de Dick KB1H
n4kg@juno.com wrote:
> Here is more corroborating evidence that a LOW
> antenna is sometimes best during daytime operation
> on the high bands. In this case, N2IC/0 found a 6L10
> at 45 ft was better than his high KT34XA stacks to Europe
> on 10 Meters during the CQ WW CW DX Contest in November
> where he set a new all time W0 record.
>
> Any other similar observations?
>
> de Tom N4KG
>
> >>>>>>>>>>>>>>>>>>>>>
>
> CQ WW SUMMARY SHEET
> >
> > Callsign Used : N2IC
> > Mode : CW
> > Category : Single-Op All Band High Power
> >
> > Station Used : N2IC/0
> > QTH : Colorado
> >
> > BAND Raw QSOs Valid QSOs Points Countries Zones
> > ___________________________________________________________
> >
> > 160CW 18 18 40 12 10
> > 80CW 162 162 451 36 18
> > 40CW 520 511 1483 85 31
> > 20CW 624 616 1788 96 33
> > 15CW 833 826 2380 112 35
> > 10CW 1101 1079 3089 115 32
> > ___________________________________________________________
> >
> > Totals 3258 3212 9231 456 159 -->
> >
> >Total Score : 5,677,065
> >
> >Equipment and Antennas
> >
> >Station 1 - Kenwood TS-950SDX + Alpha 76PA
> >Station 2 - Kenwood TS-930S/PIEXX + Alpha 76CA
> >
> >Tower 1 - 120' Rohn 25G
> >KT-34XA at 120'/65' in upper/lower/both stack
> >
> >Tower 2 - 120' Rohn 45G
> >KLM 40-3 at 120'
> >KT-34A at 115'
> >6 el 10 OWA Design at 45' fixed NE
> >160 meter half sloper
> >
> >2 phased 80 meter verticals with 4 elevated radials each
> >
> >600' Beverages NE, E, SE, SW, NW
>
> SNIP
>
> > Around 1600Z I noticed that I could run on 10 meters
> > using the KT34XA stack, and listen on the other radio
> > on 10 meters on the 6 element OWA yagi. So....
> > I could do same-band 2nd radio S&P.
>
> SNIP
>
> > I opened up on 28001 at 1525Z, but was quickly chased away
> > after 11 QSO's in 6 minutes. I didn't want to waste time finding
> > a run frequency, so I went right to 28158 ! It was a good run,
> > with OZ6PI and ER0ND being new mults. Today, I found that
> >the 6 element OWA at 45' was much better than the stacked
> >KT34XA's - On some stations as much as 2 S-units. I had never
> > seen this much of an advantage for the low antenna before.
>
> SNIP
>
> > Steve N2IC / 0
> ________________________________________________________________
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