This plot shows my low inv-V (30m apex is only 0.19 wavelengths) compared
to my 3 element parasitic vertical. Study the relative gain vs TOA plots
carefully:
Ooops...bad link. Use this one:
http://users.vnet.net/btippett/new_page_10.htm
On Mon, Apr 2, 2018 at 7:10 AM, Bill Tippett <btippett@alum.mit.edu> wrote:
> FYI in response to two recent threads:
>
> http://lists.contesting.com/archives//html/Topband/2018-03/msg00139.html
> http://lists.contesting.com/archives//html/Topband/2018-04/msg00043.html
>
> This plot shows my low inv-V (30m apex is only 0.19 wavelengths) compared
> to my 3 element parasitic vertical. Study the relative gain vs TOA plots
> carefully:
>
> http://lists.contesting.com/archives//html/Topband/2018-03/msg00139.html
>
> My observations over the past 14 years comparing both:
>
> 1. The vertical array is best 99% of the time. Usually by ~10 dB to the
> NE (e.g. EU/W1 from here). From the plots you can see this equates to TOAs
> (<20 degrees).
>
> 2. The inv-V (wires running NNW/SSE) is occasionally (1%of the time) much
> better to EU or other directions at my local sunset or sunrise. This is
> striking when it happens and is easy to detect since the inv-V is also
> better for RX than either Beverages or an RX4SQ. This is clearly some sort
> of high angle mode around SR/SS and it usually lasts for <30 minutes.
>
> 3. The inv-V BW is much broader than the vertical array which is very
> narrow (~30 kHz).
>
> 4. TX antennas are separated by about 100m on different towers and the
> 30m inv-V height is near optimum for maximum radiation straight up
> (intentionally).
>
> 5. The inv-V also works well to the SE (Caribbean/SA) even without SR/SS
> enhancement. I have no idea whether how it would behave if rotated 90
> degrees since my site doesn't allow for that.
>
> Just FYI,
>
> Bill W4ZV
>
>
>
>
>
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