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Message-ID: <D02A66602B1C4C0FB104CC081B9E0454@JimPC>
From: "James Moritz" <james.moritz@btopenworld.com>
To: <rsgb_lf_group@blacksheep.org>
References: <027601ca60a2$841cd150$0301a8c0@mal769a60aa920>
In-Reply-To: <027601ca60a2$841cd150$0301a8c0@mal769a60aa920>
Date: Sun, 8 Nov 2009 19:26:28 -0000
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Subject: LF: Re: WSPR
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Dear Mal, LF Group,

----- Original Message ----- 
From: "mal hamilton" <g3kevmal@talktalk.net>


>WSPR reports amongst stns indicate reception reports usually minus dB. Most 
>of these stations are usually PLUS dB >with me or very close to that 
>figure.
>So what does that prove.

It proves the SNR is higher at the output of your receiver than it is at 
whatever other stations you are talking about


>I would say it depends on the RX antenna and not necessarily propagation.

So how then does the signal reach the RX antenna? Radio wave propagation has 
always to be involved somewhere!


>A large antenna yields better results than a small loop or active whip.

Not if the small loop or whip are designed to achieve adequate SNR at the 
frequency of interest.


>When I switch from my 1/4 wave inv L for 500 khz to a smaller 40 m 
>resonated loop for 500 the signals then do go >down to a minus db figure.
>So what is all this all ABOUT ?

It is probably about the different directional patterns of the vertical and 
loop antennas, resulting in different signal and noise levels at the 
receiver, and therefore different values of SNR. Or maybe your loop just 
doesn't work very well.


>There is also the TX pwr to consider. Two transmitters from the same 
>location one using QRO and the other QRP will be >received at different 
>levels at a specified RX location. There is a lot of misrepresentation and 
>misleading information by >WSPR operator

This applies also to CW or any other type of signal. It is a bit rich for 
someone so shy of giving figures for his TX power to suggest others are 
being misleading...


>A trace of the signal is visible long before a decode takes place, 
>therefore why not use QRS in the first place.

Because a trace of signal is just that; a decoded WSPR signal contains 
station ID, location, and power information, making it much more useful, 
without the operator actually having to watch a computer screen 24 hours a 
day.


Cheers, Jim Moritz
73 de M0BMU