[Elecraft] RF Noise canceller ?

[Peter Zenker]

 I think no. 
White noise by definition is no statistic, therefore IMO it cannot be
eliminated because at no time it has a defined phase angle.

73 de Peter  

> -----Original Message-----
> From: elecraft-bounces at mailman.qth.net 
> [mailto:elecraft-bounces at mailman.qth.net] On Behalf Of 
> Marinos Markomanolakis, M.D.
> Sent: Sunday, April 03, 2005 3:26 PM
> To: DL2FI at qrpproject.de
> Cc: elecraft at mailman.qth.net
> Subject: RE: [Elecraft] RF Noise canceller ?
> 
> Hi Peter,
> Would this type of noise canceler not work on "white" noise also ?
> 73,
> Marinos, ki4gin
> 
> >From: "Peter Zenker" <DL2FI at qrpproject.de>
> >To: "'Marinos Markomanolakis, M.D.'" 
> ><sv9dru at hotmail.com>,<elecraft at mailman.qth.net>
> >Subject: RE: [Elecraft] RF Noise canceller ?
> >Date: Sun, 3 Apr 2005 13:03:51 +0200
> >
> >Hello Marinos,
> >
> >There have been several schematics using such technics over 
> the last 20 
> >years. Most of them use a seperate short antenna, feeding the signal 
> >pase shifted into  a combiner which combines the main Antenna Signal 
> >with the phases shifted extra antenna signal. This construction can 
> >reduce a lot of man made noise.
> >I remember there was a commercial available stand alone unit 
> sold by a 
> >small english company.
> >I myself built such a unit to help reducing my noise problem 
> especialy 
> >at 160m (I live in the middle of Berlin, Noise level in the 
> evening is 
> >> S7) But I forgot the unit during the time because I do not have an 
> >160m Antenna any longer.
> >
> >73 de Peter, DL2FI
> >
> > > -----Original Message-----
> > > From: elecraft-bounces at mailman.qth.net 
> > > [mailto:elecraft-bounces at mailman.qth.net] On Behalf Of Marinos 
> > > Markomanolakis, M.D.
> > > Sent: Sunday, April 03, 2005 6:45 AM
> > > To: elecraft at mailman.qth.net
> > > Subject: [Elecraft] RF Noise canceller ?
> > >
> > > Just a question for the technically inclined group members:
> > >
> > > How feasible or worth the effort, would be the addition 
> of an option 
> > > to the
> > > K2 which would sample RF noise from a ferquency close to the used
> > > band,(tunable?) which is devoid of signals, phase invert and 
> > > reinject the noise to an IF stage or even the antenna 
> input in order 
> > > to cancel our the "white or pulse" noise components, 
> preserving the 
> > > desired signal ?
> > >
> > > Why similar circuits are not preferred in HF receiver designs 
> > > instead of DSP filters ?
> > >
> > > Similar circuits are commonly used in biomedical devices (called 
> > > linear averagers if I am not mistaken) and are very effective in 
> > > isolating electric signals from a particular organ eg 
> Heart in EKG 
> > > or brain area of interest in EEG, filtering out the 
> irrelevant noise 
> > > from the muscle cells...
> > >
> > > Just some food for thought.
> > >
> > >
> > > _______________________________________________
> > > Elecraft mailing list
> > > Post to: Elecraft at mailman.qth.net
> > > You must be a subscriber to post to the list.
> > > Subscriber Info (Addr. Change, sub, unsub etc.):
> > >  http://mailman.qth.net/mailman/listinfo/elecraft
> > >
> > > Help: http://mailman.qth.net/subscribers.htm
> > > Elecraft web page: http://www.elecraft.com
> > >
> >
> >
> 
> 
> _______________________________________________
> Elecraft mailing list
> Post to: Elecraft at mailman.qth.net
> You must be a subscriber to post to the list.
> Subscriber Info (Addr. Change, sub, unsub etc.):
>  http://mailman.qth.net/mailman/listinfo/elecraft    
> 
> Help: http://mailman.qth.net/subscribers.htm
> Elecraft web page: http://www.elecraft.com
>