Agreed Chuck,
I maybe read David's post differently than he meant it to read also.
This progression from TX antennas to loops to Beverages to 8 circle arrays
is exactly how Hi-Z began. It is because the 8 circle is head and shoulders
above all other choices at this location that Hi-Z Antennas even exists. Many
different antennas have been tried here as well including loops and long
Beverages. Many more comparisons have been made between different types that
say under correct hardware application conditions and propagation conditions
the best signal to noise reception for DX stations is with the 8 circles. All
this says nothing about bang for the buck, real estate, or ease of installation
which is a whole different way of looking at this.
Where low angle DX is concerned I have actually measured the signal to noise
ratio of signals from different receiving antennas and indeed at my location
the best signal to noise reception follows the best RDF antenna. It may be true
that a SAL-30 is appealing for other reasons but there is no way it would ever
produce as good a signal to noise ratio on 160 meter DX signals as a properly
operating 8 circle. Active or passive either one. The SAL antenna makes a great
contest antenna as it has a wider beam width which hears more contest stations
than the very narrow 8 circle patterns. Some Hi-Z contest users actually use
both antennas so when a weak one comes along they switch to the 8 circle.
I suggest ones that have not seen them to view Frank W3LPL's videos on
receiving antennas. This is a very good presentation.
Part 1 https://www.youtube.com/watch?v=RX4eLmJWNeo part 2
https://www.youtube.com/watch?v=fyZR9uMBnIo
Everyone's mileage may vary.
Lee K7TJR
Hi-Z Antennas
-----Original Message-----
From: Topband <topband-bounces@contesting.com> On Behalf Of Chuck Dietz
Sent: Thursday, August 1, 2019 10:40 AM
To: Rodman, David <rodman@buffalo.edu>
Cc: topband@contesting.com
Subject: Re: Topband: Which RX antenna is better?
Your results of the order of performance of these antennas are somewhat
different than other, published results. I wonder if the composition of your
ground would have something to do with that? Good or poor soil? Also, how long
was the Beverage?
I have a SAL-30, which is by far my best receive antenna since I had to take
down my Beverages, but my take away was the Beverages beat the SAL-30 most of
the time. This is over medium to good soil. I would have expected the 8 circle
to be better than all the others at least 90% of the time. (At least over good
soil.)
I have been pondering which receive array to put up in a new location with
plenty of room, so I have been looking at this.
Chuck W5PR
On Thu, Aug 1, 2019 at 11:19 AM Rodman, David <rodman@buffalo.edu> wrote:
>
>
>
> This is possibly a more complicated subject than just performance. I
> gave a lecture on this topic, comparing a Hi-Z circle 8, SAL-20,
> SAL-30, beverage (unidirectional and bidirectional and BOG) and the K9AY
> array.
>
>
> In this talk, I considered performance as a factor, but also
> considered maintenance, size, mechanical stability, cost and ease of
> construction and installation.
>
>
> All things considered, the top 2 at my QTH were the Hi-Z circle 8 and
> the SAL-30.
>
>
> Here is a quick summary of my findings.
>
>
> Circle 8: highest cost, most complex to install and construct,
> requires large footprint of land, best of all antennas as it requires
> almost NO maintenance and performance second overall to the SAL-30.
>
>
> SAL-30: modest cost, modest install and construct, modest footprint,
> requires minimal repairs (usually to the coupler wires) but overall
> performance best of all for directionality and gain.
>
>
> SAL-20: modest cost and somewhat simpler than SAL-30 to install and
> small footprint. Performance almost identical to the K9AY array.
>
>
> K9AY: modest cost but slightly more complex to construct as compared
> to
> SAL-20 and about the same size. Performance less than SAL-20 due to
> fewer directions.
>
>
> Beverage unidirectional: mechanical stability good when constructed
> with copper coated steel wire #14 or larger. Gain fine when desiring
> only 1 direction. Depending on the location may be placed in half a
> day from start to finish.
>
>
> Beverage bidirectional: mechanically unstable when constructed with
> commercial products using either RG6 or twin lead. Requires frequent
> repairs due to fatigue or failed connections. Performance overall is
> not on par with other directional arrays.
>
>
> BOG: simplest of all antennas to construct, install and maintain. Can
> be installed in an hour or two. Should be unfolded at spring time
> each year to keep wire from being incorporated into lawn. Convenient when
> only 200'
> available. Can be band specific.
>
>
>
> Just a quick summary. My location does not lend itself to beverage
> construction. about 2/3 of my 25 acres are heavily and complexly treed
> with brush so overgrown that it can be a chore to do almost anything
> for installation or repair. This is why I prefer the SAL-30 overall.
> The circle 8 took me one summer (as my only project to install) by the
> time the land was cleared, site measured, antennas constructed and all
> the coax installed. The trade off is that this antenna has been the
> most mechanically stable of any antenna that I have ever had.
>
>
> ---
> David J Rodman MD
> Assistant Clinical Professor
> Department of Ophthalmology
> SUNY/Buffalo
>
> Office 716-857-8654
> _________________
> Searchable Archives: http://www.contesting.com/_topband - Topband
> Reflector
>
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