Posted by
David Woolley (E.L) on
Nov 01, 2010; 7:53am
URL: http://elecraft.85.s1.nabble.com/K3-APF-Adjustable-Q-tp5688670p5693005.html
Quote para 2, both points: Reciprocity still applies with respect to
gain and off axis effects. If the receive antenna is down by 3dB, it
will be down by 3dB EIRP when transmitting; if down by 10dB, the EIRP
will be down 10dB.
Quote para 3: Local noise does make a real difference and will
compromise reciprocity.
Top quoted only by list policy.
Kok Chen wrote:
> Although Reciprocity Theory states that if both of you use the same
> power, the received power at the two antenna terminals will be the same
> independent of what antennas are at each end, other things determine if
> he can copy you better than you can copy him.
> However, another factor, arguably more important, is the antennas'
> directivity and where the directivity are aimed at. If his antenna is
> more directive than yours by 3 dB, all else being equal, he has a 3 dB
> of SNR advantage. If the arrival angle of his signal at your antenna is
> 10 dB below where your antenna actually peaks, while your signal arrives
> at his antenna where the response of his antenna peaks, you have yet
> another 10 dB disadvantage, etc.
> The same SNR argument applies to how noisy his local RF environment is
> compared to your environment.
--
David Woolley
"we do not overly restrict the subject matter on the list, and we
encourage postings on a wide range of amateur radio related topics"
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