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FW: Re:spectran,dspfil, please clarify (Arie Dogterom Oct 01 2002)

-----Original Message-----
From: owner-linrad@xxxxxxxxxxxxxxxxxxxxx
[mailto:owner-linrad@xxxxxxxxxxxxxxxxxxxxx]On Behalf Of Arie Dogterom
Sent: Tuesday, October 01, 2002 10:44 PM
To: linrad@xxxxxxxxxxxxxxxxxxxxx
Subject: Re: [linrad] Re:spectran,dspfil, please clarify

Bonjour Dom,

Yes that could be interesting. But..... till now the waterfalls on my
windows dsp programmes are much much faster than on linrad with 5000, 8000
or 16000 hz sampling. Higher rates are not possible with my linrad. But in
Windows I easily can run 48 kHz sampling.
I currently of course only can view the 3 kHz audio as I have not made any
convertor to audio from RF.
But in practice ( contests) the frequency uncertainty even on 10 GHz has not
made too much of a problem. I can almost always find the other station as
the beamheading is known ( we normally start on 23 cms if there is no
rainscatter and the beam then is almost ok) by slowly tuning. If the signal
is copyable I always can find it so I did not feel the need for a waterfall.

----- Oorspronkelijk bericht -----
Van: DEHAYS Dominique <Dominique.DEHAYS@xxxxxxx>
Aan: <linrad@xxxxxxxxxxxxxxxxxxxxx>
Verzonden: 1 oktober 2002 9:03
Onderwerp: Re: [linrad] Re:spectran,dspfil, please clarify

> Hi Arie and the list ,
> what is very interesting with LINRAD ( among many other nice features)
> when you are a microwave ham , is to be able to look at 90Khz of the band
> and find signals even if they are very weak . You know like me that
> frequency accuracy is a pb on microwaves so you never know if the guy you
> are trying to work will be on the right frequency or not , LINRAD solves
> that problem...
> One problem with weak microwave signals is that LO's are obtained by
> multiplication of a 100Mhz signal to 5/10/23/xx Ghz , so the signal has
> quite a poor phase noise , and it is difficult to get improvement by using
> a sharp filter . I can see , for example, this problem on a 23cm beacon
> located about 250km from here , when I look at the spectrum on the BSZ
> PC-RX ( DOS version) the CW signal is very , very broad compared to a 2m
> beacon.
> 73's Arie
> Dom/F6DRO