[Elecraft] K3 - RX audio degradation with ANF

[Lu Romero]

I agree, in more ways than one, that we are talking apples
and oranges here.  The code between the devices has similar
applications, but a Sabine Feedback Destroyer has multiple
instances operating in a dedicated processor with nothing
else to do but find the "carriers" while the K3 ANF is
sharing its runtime with lots of other "priorities".

Another issue is that the ANF cannot "remove" the audio
covered up by the interfering carrier, NOTHING can do this. 
All ANF can do is throw a notch over the interfering
frequency... That is what it does, it cant actually REMOVE
the coherent interferance from the "incoherent"
intelligence.

I was just at the NAB show where I saw a demonstration of a
technology that does extract the underlying audio, which was
truly magic. Also saw a demo of a video editing system
(Adobe Premiere) that has a similar feature built in. Lots
of non real time processing is needed to do this magic,
however. 

If the ANF can be made better, great.  I find it acceptable.
 Not perfect, but acceptable.  If making it better doubles
the price of the radio, then Im not for it, for what its
worth :)

-lu-w4lt-



Message: 24
Date: Sat, 19 May 2012 16:50:24 -0500
From: W4ATK <w4atk at bellsouth.net>
Subject: Re: [Elecraft] K3 - RX audio degradation with ANF
To: Bill <bill at w2blc.net>
Cc: elecraft at mailman.qth.net
Message-ID:
<74BDCAF3-FCA6-44DF-A0E5-21728E101625 at bellsouth.net>
Content-Type: text/plain; charset=us-ascii

I think we may be comparing apples to oranges here.

In the K3 digital ANF, the notch filter is looking for
coherent signals. The premise
is that audio is less coherent than a CW carrier.  Thus the
ANF "finds" the
coherent CW carrier and notches it out,  leaving the
remaining audio.