[Elecraft] [K3] K3 NR

[Joe Subich, W4TV]

> I prefer the sound of the 3.25 version for ssb, its cleaner 
> and somewhat less bright (flatter in response).  I had to 
> tweak the RX EQ to add some bass in the 3.27 version or it 
> sounds "harsh" in my headsets (I dont use speakers hardly 
> ever, btw). 

What is the impedance of your headphones?  With anything less 
than 100 Ohms or so, the stock 10 uF headphone coupling caps 
cause a significant LF roll off - particularly with 8 Ohm cans. 

73, 

   ... Joe, W4TV 
 



> -----Original Message-----
> From: elecraft-bounces at mailman.qth.net 
> [mailto:elecraft-bounces at mailman.qth.net] On Behalf Of Lu 
> Romero - W4LT
> Sent: Wednesday, August 26, 2009 10:09 PM
> To: elecraft at mailman.qth.net
> Subject: Re: [Elecraft] [K3] K3 NR
> 
> 
> 
> Lyle:
> 
> Just played with the NR in both SSB and CW, on 80 and 40.
> 
> First, I can hear the change of the filters now without 
> turning things on and off, as you mentioned it would work.  
> The frequency response is decidedly less "flat" (less bassy) 
> than the sound of 3.25.  For CW, the 3 and 4 settings are 
> much more efficient, not so in SSB, where the 1 and 2 
> settings are much cleaner sounding and better copy.  I found 
> that with no antenna and with the RF gain turned to 12 
> o'clock... Turn on the NR and all receiver white noise mutes 
> and slowly ramps up.  That's a recursive effect, I guess.
> 
> I prefer the sound of the 3.25 version for ssb, its cleaner 
> and somewhat less bright (flatter in response).  I had to 
> tweak the RX EQ to add some bass in the 3.27 version or it 
> sounds "harsh" in my headsets (I dont use speakers hardly 
> ever, btw).  Inteligibility is marginally better with 3.27 on 
> ssb and quite a bit better on CW, so you have drifted a bit 
> to the CW side of the equation, but with a decent compromise for SSB.
> 
> No more boingy peakyness in any mode, which is good, and the 
> level while it still drops a bit, is better behaved.
> 
> Can I assume from some comments I have read here that the NR 
> process is pre
> EQ and AGC?  How exactly do the processes "stack" in the 
> radio architecture?   
> 
> If NR is at the top of the stack, a decent "fix" might be to 
> somehow gang these three processes using presets so that they 
> can be set up ahead of time and recalled from a memory button 
> by the user.
> 
> As an old brodcaster, we used to preset things in Switchers 
> (vision mixers to UK readers) using a process called E-MEM... 
> Which could recall preset parameters in "salvos" to preset 
> multiple settings.  This might work here.
> 
> This would be handy in a contest environment where a minimum 
> of tweaking and rapid adaptation to changing conditions is 
> needed... You could play outside of a contest and create the 
> settings then in the heat of battle, recall them with a 
> single button push from a "canned" setup.  It wouldnt be 
> perfect for any environment, but it might mean the difference 
> between working a mult and not working a mult.  And 
> multipliers, after all, are.... :)  
> 
> As you said, every receiving environment is different, but 
> some generalizations can be made and being able to recall the 
> multiple settings would be a definite plus feature of the radio.
> 
> Thanks for letting us test these iterations. 
> 
> Lu Romero - W4LT
> K3 # 3192 
> 
> 
> Lyle Johnson wrote:
> > 
> >> ...For now I'll treat the parameter as an opaque
> >> series of magic numbers.
> > 
> > The way the new beta NR works is:
> > 
> > Fx-y
> > 
> > x selects the length of the filter.
> > 
> > F1 = 121 taps, F2 = 91 taps, F3 = 61 taps, F4 = 31 taps
> > 
> > (The Beta 3.25 release used FIR filters of 61 taps.)
> > 
> > y selects values of Beta (gain), decay, and delay (how long the NR
> > algorithm waits to process a signal)
> > 
> > (The Beta 3.5 release used the "x" parameter for these selections)
> > 
> > 73,
> > 
> > Lyle KK7P
> > 
> > ______________________________________________________________
> > 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
> > 
> > 
> 
> -- 
> View this message in context: 
> http://n2.nabble.com/K3-NR-tp3515659p3520809.html
> Sent from the [K3] mailing list archive at Nabble.com. 
> ______________________________________________________________
> 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