[Elecraft] Clean 600hz signal, full dsp decoupling possible?

[pd0psb]

Hello Dick!

An SDR program called Winrad is capable of exactly what you thought.
It is a function called "despread" aimed for weak-signal copying (EME and
such)

http://www.sdrham.com/winrad/index.html
It's freeware working with several SDR receivers but you can also feed K3
audio into it.

There's a good audio example of "re-synthesized CW" on this page.

73'
Paul
PD0PSB 




PA3CW wrote:
> 
> Hi Geoff,
> 
> Thanks for your reaction. I am very curious whether the modern DSP
> technology can discriminate signal from noice (in CW) better than the
> human ear and I dont know if it would be boring to just hear a clean tone
> whilst the signal is at a minimum level. I think it will be an amazing
> thing to experience as you do expect having to put in a lot of effort to
> hear the signal through a lot of noise. The second step is if the DSP of
> the K3 is able to include such a setting or external 'tracking filter' is
> necessary.
> 
> Best,
> Dick ... . . .._
> 
> 
> 
> Geoffrey Mackenzie-Kennedy wrote:
>> 
>> Hello Dick,
>> 
>> I am not a DSP expert either, but a tracking filter keying an audio 
>> oscillator will do exactly what you want. In its simplest form a tracking 
>> filter is a phase locked loop, and ICs which can be used at audio for
>> this 
>> purpose have been available since the 1960s and are inexpensive. Also a 
>> tracking filter working at audio can be connected to a receiver's low
>> level 
>> audio output if one is not already in the receiver. I believe that the
>> DSP 
>> wizards have already designed something that does the same job.
>> 
>> Tracking filters are very useful when searching for signals below the 
>> receiver's noise floor, at VHF for example, but listening to a keyed
>> audio 
>> oscillator without noise can be quite boring.
>> 
>> 73,
>> Geoff
>> GM4ESD
>> 
>> 
>> 
>> ----- Original Message ----- 
>> From: "PA3CW" <pa3cw at planet.nl>
>> To: <elecraft at mailman.qth.net>
>> Sent: Saturday, October 17, 2009 8:57 PM
>> Subject: [Elecraft] Clean 600hz signal, full dsp decoupling possible?
>> 
>> 
>>>
>>> Hello forum friends,
>>> Not being an expert in the world of DSP, but being an experienced CW
>>> operator i often asked myself this question:  Why is there no full
>>> decoupling between the received signal and the tone in the headset or
>>> speaker? In other words is it possible that the dsp discrimiates enough
>>> between signal and noise and steers a clean LF oscillator making a clean
>>> 600hz or so tone?  Is such a setting possible or do i overlook something
>>> here? Just a little out of the box thinking...
>>> Dick PA3CW
>> 
>> 
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> 
> 

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