[Elecraft] k3 NR Audio level increase

[Steve Ellington]

Interesting. For CW I always use the NR to dig out the weak ones. The effect 
is amazing. I believe the reason we all see this differently is due to AGC 
settings. THR, SLP etc. really affect the NR.
Steve Ellington
N4LQ at carolina.rr.com
----- Original Message ----- 
From: "Don Wilhelm" <w3fpr at embarqmail.com>
To: "Joe Planisky" <jplan at jeffnet.org>
Cc: <Elecraft at mailman.qth.net>
Sent: Saturday, April 25, 2009 5:14 PM
Subject: Re: [Elecraft] k3 NR Audio level increase


> Joe,
>
> I tried your suggested settings, and yes I found an increase in audio
> volume.  I also observed that the NR worked as a squelch at that
> aggressive setting.   I normally use F1-3 or F1-4 for NR and have no
> problem.
>
> I don't use NR when attempting to copy a weak signal.  When the weak
> signal is down in the noise level, the NR algorithm cannot distinguish
> between the noise and the signal with certainty.  My ears do a better
> job despite the noise, so I turn NR off when digging for the weak ones.
>
> 73,
> Don W3FPR
>
> Joe Planisky wrote:
>> Don,
>>
>> Try this:
>>
>> 1. Set mode to CW, BW to 2.00, RX EQ = flat.
>>
>> 2. With no signal tuned in, hold NR and set to F4-4. Tap NR twice to
>> turn off NR.
>>
>> 3. Tune in an S9 signal, or better yet, use a signal generator (I use
>> an XG2).
>>
>> 4. Set RF gain to max, AF gain for a comfortable volume.
>>
>> 5. Tap NR to turn on noise reduction. (You might want to keep one hand
>> on the AF gain control :-)
>>
>> On my K3 (with FW 3.11), turning on NR under these conditions boosts
>> the audio output voltage by 17.2 dB according to the built-in AFV meter.
>>
>> Using less aggressive NR parameters results in less of a boost, down
>> to 6.3 dB at F1-1.
>>
>> Now tune in a weak signal (say, S3) and repeat the steps.  The boost
>> is still there, but very much reduced (On my rig at S3 and NR=F4-4,
>> the boost is 6.3 dB, at NR=F1-1 it's 1.4 dB)
>>
>> Now imagine trying to copy a signal that rapidly fades between S3 and
>> S9 with NR on.
>>
>> 73
>> --
>> Joe KB8AP
>>
>>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:Elecraft at mailman.qth.net
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html