[Elecraft] K3: APF effectiveness

Don Wilhelm w3fpr at embarqmail.com
Tue Jan 25 20:25:24 EST 2011


  Ralph,

You have heard that to reduce the ringing, increase the DSP bandwidth.  
The 50 Hz filter width has a bit of ringing by itself, so add the APF 
and the situation becomes more pronounced.

You can't have your cake and eat it too.  The bit of ringing will bring 
out weak signals just like the old Q-Multiplier used to do (and it 
caused "ringing").  The APF was not intended to be used full-time, turn 
it on only when it will help -- besides, it is too sharp for "tuning 
around".

73,
Don W3FPR

On 1/25/2011 7:40 PM, Ralph Parker wrote:
>> ...perhaps less gain and a little wider BW
>> or give the user the tools to do it ourselves.
> I was thinking exactly that myself last night on 160m - no problem with the
> bandwidth, but I'd gladly give up a db or two of APF gain to reduce the
> ringing.
> Because of the ringing, I can hear signals that aren't even there!
>
> Ralph, VE7XF
>
> ______________________________________________________________
> 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
>


More information about the Elecraft mailing list