[Skimmertalk] Skimmer and Live Audio

[Pete Smith]

At 04:15 PM 12/8/2008, Stan wrote:
>Pete,
>
>This is something I wanted to ask about anyway.  Are those numbers pretty 
>accurate or relatively accurate to each other?
>
>Perhaps it is just a bad assumption to think that stations are running 
>anywhere close to 1500W.  It is hard to see how some stations are 30 dB 
>higher in Europe than others in close proximity with antennas that are 
>within 3 dB of the same gain.  Seems a lot more than could be explained by 
>QSB if it is accurate.
>
>I guess a good trial would be to call CQ with a given amount of power, 
>quickly cut it in half and call again to see if the results are a decrease 
>by 3 dB.  Has anyone done this?

Hi Stan - not to my knowledge.  It would be a good test, particularly if 
repeated a number of times.

As to the accuracy, QSB in the time between observations would certainly 
affect the accuracy of the comparisons, as would QRM.  The software is 
certainly capable of accurately comparing the signal strength during a dot 
or dash and the noise level between dots and dashes.  Of course, for any 
given station noise and antenna gain and directivity all would affect the 
absolute numbers.


So far, in looking at the SNRs of the east coast multi-multis I've been 
surprised by how little difference there is.  I would expect, particularly 
at the beginning and end of an opening, to see some real differences 
because of antenna height or antenna selection.  For example, if the op at 
K3LR is running EAs on 15 while the person at KC1XX has just switched to 
the top yagi in order to pickup a whisper-weak UA6, there might be a big 
difference between their signals at the two locations.  Other than that ... 
but then, we know that a lot of those big signals require 3-phase power, 
don't we?

73, Pete N4ZR