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Date: Sun, 03 Sep 2006 13:28:12 +0200
From: Wolf DL4YHF <dl4yhf@freenet.de>
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Subject: Re: LF: sri for RX troubles
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Status: O

Hello Dick,

Thanks for the QSO this morning. I would never have thought that the 
program runs on a machine with 16 MB RAM !

About the overloading problem: I have similar problems here when strong 
stations are on the band. There is:
A) a certain spectral leakage from the FFT calculation, which is normal, 
but usually in the 10-Hz-range
B) deafening of the receiver, which usually much worse and cannot be 
cured by post-processing.
I can imagine that PA0BWL (hello Wil !) is extremely strong at your 
location. He is also one of the strongest signal here.
The IC706 which use a the club (after the 136 kHz <-> 10 MHz 
transverter), the S-meter usually shows nothing on the LF band, only 
occasionally S1. If it shows S9, the sensitivity of the whole system may 
be decreased by 54 dB (worst-case), because most comercial receivers 
actually show the AGC voltage as fieldstrength indicator. To get away 
from that problem would mean building a receiver without AGC, which 
would require an enormous dynamic range (it can be done, though, using 
software-defined radio principles).
But usually, there is so little activtiy that we are happy to see 
anything at all ;-)

BTW Jeff F6BWO was calling you too, but I guess he was a bit weaker than 
usual. Nice to have some regular CW activity too - worked G3XDV again 
after a very long time.

Best regards,
  Wolf DL4YHF  /   DK4U (on LF) .

Dick schrieb:
> Hello all,
>  
> I've been (and will be on again this afternoon)  on DFCW 137.7kHz.
> I have some trouble with my computer, which is an laptop with only 
> 16MB workmemory.
>  
> So, therefore it often takes some time to switch from RX to TX  
> (Speclab to QRSS window)
>  
> I also haven't optimized the settings off spectrum Lab, not able to 
> read weak signals.
> I saw DK6NJ?? calling me, and later somebody else, but couldn't get 
> the dashs and dots all
> that clear on my screen.
>  
> Also have problems when a strong signal is on the band.....it blocks 
> other weak signals that are within 50Hz or so.
> Hopefully this is just a way of wrong computer settings,hi.
>  
>  
> I'll go on now
>  
> 73
>  
> Dick, PA4VHF