Polarization / Wave Angle Effects at N4KG
My experiences on the high bands during SUMMER is that higher
antennas are usually better most of the time indicating low wave
angles which one would expect when the MUF is low whereas
in the FALL, Winter, and Spring, my low antennas are often better
during daylight hours.
On 80 meters in the SUMMER, I have heard VK's and even FR5DX
via the LP, up to an hour and a half past sunrise. This I attribute to
the slow rise in MUF during summer due to ionospheric heating
which pushes the ions higher in altitude resulting in lower ion
density. I expect this same phenomenon applies to 160M during
summer conditions. Before any conclusions are drawn, I believe
that observations need to be made during all 4 seasons.
I have recently added high dipoles on 80M to my antenna farm.
The flat dipole broadside to Europe with ends at 140 ft is usually
best to south, central, and western Europe, but on several
occassions to Scandanavia (30 degree heading), my GP will
often be stronger, sometimes by as much as 6 to 10 dB on
both receive and transmit, regardless of antenna polarization
of the Scandanavian station.
To South America, the Antarctic Islands, and SE LP (VK0IR) my
140 ft high inverted vee is usually best, especially before sunset.
A 90 ft high 100 ft center-fed (ladderline) dipole was noticably
better than my GP to 3Y0PI one morning before my sunrise,
enabling a one call QRP contact at their sunrise.
This past winter I was able to contact BV, BY, V85, 9M6, 9M0C
on 75M via the very long and difficult short path at my sunrise
using a new 140 ft high inverted vee which seemed to have
the edge over my 80M GP.
On 160M I often notice that guys further north cream me to close
in Caribbean stations. I expect that it is useful to have BOTH
vertical and horizontal polarization on 160M just as is the case
on 80M.
de Tom N4KG
............................
On Sat, 1 Aug 1998 12:08:09 EDT K3BU@aol.com writes:
>
>
><<de W8JI:
>When I compared a dipole at 160 feet to a 3/8 wl vertical with a GOOD
>ground system, the dipole NEVER beat the vertical at any time. Most
>contacts reported the vertical two S units or more above the
>dipole. The dipole was solidly better within the state of Georgia.
>>>
>
><<de W4ZV:
>I had somewhat different results in Colorado which indicated high
>angles after
>sunrise.
>1. Before sunrise (~1 hour to 10 minutes before), vertical was
>usually
>stronger by 1-2 S units.
>2. At sunrise (~10 minutes before to 5 minutes after), both antennas
>were about equal.
>3. After sunrise (~5 minutes to 40 minutes after), dipole was usually
>stronger by 1-2 S units.
>>>
>
>"Thank you for your support Bill!" After W8JI results I started to
>wonder what
>was wrong with my findings.
> From brief description of Tom's experiments, I just wonder if Inv
>Vee was
>too high (I usually had it between 40 - 80 ft), what time of the
>sonrise/sunset (season?) were reports compared, was reporting done
>only by RX
>or also TX. Appears to me that when high angle prop is happening, it's
>benefit
>is more pronounced on transmit.
> Also Bill, K0HA comments about "beaming wrong way" are valid. Year
>ago I
>was told that many US stations were calling me that I didn't answer,
>while I
>was using 4sq. and "slow-switchable" beverages beaming Eu. So in the
>last CQ
>WW I had two rigs, one with 4 sq and NE to S beverages on right ear,
>another
>rig with Inv Vee and NW, N, SW beverages on left ear. At the times
>when band
>was open "both ways" I was trasmitting on both antennas, and it sure
>helped,
>picked up quite a few stations that were not audible on the other
>setup. (What
>a weird stereo effect! Sometimes I could hear stations on "stereo",
>when they
>couldn't be copied on each channel alone!)
> It also appears that propagation is enhanced on the path where
>there is
>salt water in between. Caribbeans on 160 at VE1ZZ are unbelievably
>loud
>compare to my NJ QTH. On the other hand, rocky area, ground is like
>anechoic
>chamber, signals die there, sucked in by the rocks.
> 73 Yuri K3BU, VE3BMV maybe from VO1 in WW?
>
>--
>FAQ on WWW: http://www.contesting.com/topband.html
>Submissions: topband@contesting.com
>Administrative requests: topband-REQUEST@contesting.com
>Problems: owner-topband@contesting.com
>
>
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