To: <topband@contesting.com>
>Date: Tue, 08 Oct 1996 07:50:32 -0400 (EDT)
>From: Bill Tippett <btippett@ctc.net>
>Subject: Re: TopBand: 160 Magic
>To: topband@contesting.com
>Sender: owner-topband@akorn.net
>
>At 08:38 10/7/96 -0500, you wrote:
>
>> Comparing receive antennas on ZB2FK produced interesting results...
>>With harvest not done yet here, all of my beverages are not up yet.
>>Currently I have them at 8, 43, 84, and 323 degrees. 323 was the best
>>of the four!
>
>Bill, best reception on Beverages at right angles to the desired path
>is often an indication of very high angle propagation conditions. When
>I used to observe this from Colorado, I would immediately switch to my
>dipole and often found that to be the best receive AND transmit antenna.
>If you have one, give that a try next time. Although mine had an apex
>at 45 meters with the ends at 30 meters, the radiation pattern was still
>straight up due to the low height in wavelengths above ground. This
>effect is especially noticeable around sunrise and sunset.
>
> 73, Bill W0ZV
>
Hi Bill,
Hope that you did well in this weekend's CQWWSSB Contest. Working
JA's on 15 meters on Sunday reminded me of this past note exchange.
I had my Yagi pointed SSW working the South Pacific. I heard some weak
JA's while pointed this way and immediately had thoughts of an opening
to Japan/Northern Asia similar to this morning's opening to Europe on
15. I turned the Yagi towards Japan and found that the signals almost
disappeared. Turning further east (past Japan) did not bring up the
signals again. I found a broad peak in signal from 210 - 270 degrees.
Immediately after the contest I listened on 17 meters. I heard a
JA calling CQ there. Using a different Yagi at a different height
17 meters high there vs. 27 meters high on 15) on a different tower,
I found that his signal peaked from the same direction (240). I've had
similar results from central European signals on 15 meters with their
signals peaking with the beam at 130 degrees.
Now a disclaimer on my past beverage memo: my 323 degree beverage was
(and still isn't) at its full length (due to the corn still not harvested)
and is not terminated at this shorter length (about 350'). It obviously
was actually a 143/323 degree bidirectional beverage.
Tonight's JA propagation made me want to test your high angle theory
on 160 beverage reception. Using EZNEC software and my actual beverage
modeling I found the high angle lobes at right angles to the beverage's
direction. However, in comparing dBi values, the dBi figure for high
angle reception in line with the beverage wire was a larger figure than
the dBi value for high angle reception on a side lobe. Assuming equal
noise from all directions, my beverage would still receive a high angle
signal better in-line with the wire rather than a second one at a
right angle to it.
That make's me feel that some past 160 meter European contacts along with
some on 15 meters (and tonight's to Japan) were made via a bent path...
I'll have to try some of my shorter (high angle) receive antennas
for another check of this...
There was no magic on 160 for me during this weekend's contest.
Static was high and polar path skip unheard in Nebraska. Hopefully
we won't get a repeat performance after a 27 day solar revolution...
73, Bill K0HA
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