On 11/5/2011 7:54 PM, Leif Asbrink wrote:
Snipped a bunch of interesting good stuff.
Such a narrow filter must be exactly centered on the carrier
and therefore an AFC (automatic frequency control) is needed.
You have to find the signal first, before AFC can be used.
That is trivial. Signals
Hi Alfred,
You can see it on the waterfall. I always operate with the panadaptor
and waterfall displayed, and can click on the signal of interest. I was
wondering if you had an automatic way of doing that.
No. There are typically many signals and I have no idea
about what the operator would
On 11/4/2011 2:20 PM, Leif Asbrink wrote:
I don't think the FLEX system is any better or worse in this regard, as
it is a fundamental limit to signal processing.
For SSB I think you are right, but not for CW, AM and FM.
CW we'll get to in a moment, but I don't consider AM or FM to be weak
Hi Alfred,
The signals I am talking about are at or just below the noise level.
Once the signal is +3dB or better then NR can make it more pleasant to
copy because I find it less fatiguing, but it certainly would be
copyable anyway.
That is what I have concluded from making some tests.
I
K0DAN k0...@comcast.net wrote:
You're right, there's many types of noise. A few (for example ignition
pulse) is easily handled
Yes:-)
but that damn propagation frying noise, power
supplies, splatter, etc., are another matter altogether.
Yes. I am trying to build a library of
-radio.biz
Subject: Re: [Flexradio] Setting up DSP Noise Reduction on PSDR 2.2.3
K0DAN k0...@comcast.net wrote:
You're right, there's many types of noise. A few (for example ignition
pulse) is easily handled
Yes:-)
but that damn propagation frying noise, power
supplies, splatter, etc
Hi Tony,
There is a lot of literature on this subject, just a Google away. There are
also labs devoted to developing commercial applications of DSP noise
reduction. Here are some links:
http://www.dspalgorithms.com/products/nr.html
http://www.bhi-ltd.com/
On 11/3/2011 12:29 PM, Leif Asbrink wrote:
I think commercial applications need a reasonable S/N to start with -
and as amateurs we would then be able to copy without DSP
assistance... 73 Leif / SM5BSZ
Yes. I have used many rigs, including some high-end ones and several
external DSP units, and
On Thu, Nov 3, 2011 at 2:29 PM, Leif Asbrink l...@sm5bsz.com wrote:
...I do not think available softwares are useful at the
detect threshold for amateur SSB
=
Probably not. There are really two issues here: the relative amplitude of
signal and noise, and the ability of software to tell
You're right, there's many types of noise. A few (for example ignition
pulse) is easily handledbut that damn propagation frying noise, power
supplies, splatter, etc., are another matter altogether.
Noise, at least to the ear and human acoustics, is subjective anyway.
Older ears and brains
, K0VM
On 11/1/2011 12:00 PM, flexradio-requ...@flex-radio.biz wrote:
Date: Tue, 1 Nov 2011 11:15:07 -0400
From: Joe Wordjoe.n...@gmail.com
To:flexradio@flex-radio.biz
Subject: [Flexradio] Setting up DSP Noise Reduction on PSDR 2.2.3
Message-ID:
calzppkhst-s+z04re6fxlodgd5sfjubmbftmsu0
in the way.
AL, K0VM
On 11/1/2011 12:00 PM, flexradio-requ...@flex-radio.biz wrote:
Date: Tue, 1 Nov 2011 11:15:07 -0400
From: Joe Wordjoe.n...@gmail.com
To:flexradio@flex-radio.biz
Subject: [Flexradio] Setting up DSP Noise Reduction on PSDR 2.2.3
Message-ID:
calzppkhst-s
-radio.biz
Subject: Re: [Flexradio] Setting up DSP Noise Reduction on PSDR 2.2.3
Part of the problem may be a matter of PC processing power forreal-time
noise removal. I use audio editing software on my PC that does an
outstanding job of removing complex noise from audio recordings.
However
well, I have to 'chime in..' after hesitating...
to me, 'it depends..' on what noise you're trying to get rid ofI spend
most of my time on 160m cw, but in the suburbs with all sorts of 'mystery
signals'...using small receiving antennas, which require external
pre-amps...it's a curious
On Wed, Nov 2, 2011 at 10:40 AM, K0DAN k0...@comcast.net wrote:
...Maybe our expectations of SDR are exaggerated...
===
Well, it doesn't really have anything to do with SDR. Just about all radios
today have DSP, and in fact the DSP in some superhet radios has more
processing power than most
Hello Bill,
Part of the problem may be a matter of PC processing power forreal-time
noise removal. I use audio editing software on my PC that does an
outstanding job of removing complex noise from audio recordings.
However, it takes over 10 seconds to clean-up 1 second from a recording,
Hello Dan,
I have read, and now believe, that analog rigs with
their crystal filters lengthen the noise pulses,
making them harder to get rid of
Yes. That is absolutely true. Here is an extreme example:
http://www.sm5bsz.com/lir/recordings/static-rain.htm
Static rain needs a sampling
On Wed, Nov 2, 2011 at 6:58 PM, Leif Asbrink l...@sm5bsz.com wrote:
...I am convinced that any processing that could be made on an audio
stream could
be made efficient enough to run in real time on a modern (super)
computer...
==
There is a lot of literature on this subject, just a
It would be nice if NR worked. I also have not found any settings that
were useful.
It would also be nice if NB and NB2 worked, if you set the level to
eliminate the noise, it distorts the audio and brings in splatter from
off frequency signals.
I hope Flex has plans to fix these issues.
Joe
Lots of confusion on NR vs. setting the AGC threshold (AGC-T) properly. Tim
definitely has it right that your first line of defense against
ear-unpleasantness is to properly set the AGC threshold. (It should be
automatic but it isn't. Yo! Flex! This is very basic functionality!) First
some
On Tue, Nov 1, 2011 at 10:53 AM, Brian Lloyd brian-wb6...@lloyd.com wrote:
... I have never found any combination of settings that seem to make it
usable
===
True. Flex is not alone in this; some other radios with extensive DSP
capabilities also do poorly with NR. The DSP filtering in
Brian you make a key point. I have yet to find a radio (and I use many, both
modern and boatanchor) that have noise reduction which really improves
things. Yes, occasionally engine impulse noise, the new Flex TNF's are
certainly outstanding for heterodynes and maybe some adjacent splatter,
Actually, Terry, the AGC-T works every bit as well on weak signals as on
strong ones. If you observe Flex's guidelines for use of the AGC-T, you
will find that there is an interactive sweet spot that can be located
through judicious use of the audio gain and the AGC-T. That sweet spot
actually
Can someone direct me to a good tutorial that will help me get the most out
of noise reduction on receive. I've played around in PSDR, read the manual
and tried the knowledge base. Help, anyone? Thank you.
Bill Roberts
Radio Station K8DXX
Don't use the NR and use the AGC-T control instead. It works better on
a greater variety of noise types.
http://kc.flexradio.com/KnowledgebaseArticle50153.aspx
-Tim
---
Tim Ellison, W4TME
Product Management, Sales Support
FlexRadio Systems^(TM)
4616 W Howard Ln Ste 1-150
Austin, TX 78728
Hello Tim
While I thank you for the tip regarding using the AGC-T control instead
of the NR, I am a bit dismayed that this implies the NR function is
basically not worth using. When NR is needed most is not on strong
signals but weak ones. Turning back the AGC-T control will reduce the
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