[Elecraft] K3/KX3 Operating Tip: APF (audio peaking, filter) for weak-signal CW work

[drewko]

Just wondering if there are others who would prefer that the APF state
NOT be remembered by the WIDTH I/II preset? For some reason that has
always rankled me a bit. Would prefer to have APF changed only by
means of the DUAL PB button.

73,
Drew
AF2Z



On Thu, 28 Jun 2012 03:27:00 -0700 (PDT), you wrote:

>
>G3XDY wrote
>> 
>> I find the K3 APF invaluable for weak signal work on the microwaves. In 
>> the microwave NAC contest last night I worked three stations over 600km 
>> on 2.3 and 3.4GHz by aircraft reflection, and the APF really helped pull 
>> the weak signals out of the noise. I generally use 1kHz width for CW and 
>> my ears for the rest of the filtering, but the APF makes a really big 
>> difference on those signals that seem just too weak to copy.
>> 
>
>Coming from a totally different operating perspective (low band DXing), I
>agree with John.  For signals in white noise (i.e. at or below the noise
>floor), I use a wide XFIL (e.g. Inrad 500 with DSP setpoint at 600) and then
>carefully peak APF in 1 Hz steps using FINE.  With any other signals in the
>XFIL passband including impulse noise (e.g. lightning), I do better without
>APF.
>
>73,  Bill