[Elecraft] APF measurements: FW 4.17 better results by 2 dB

[Don Wilhelm]

  Bill,

I am not suggesting Elecraft do anything other than the explanations 
that have already transpired.
Yet even with such dialog and tests that say "Q. E. D.", there will be 
many who remain unconvinced, and will want to stick with the old version 
"because it is better".  They will not be convinced until they have 
received countering information with their own ears.

There may be other factors involved -- although there were no 
intentional changes in the DSP firmware to change the noise response of 
the K3, that is one possible factor that comes to mind.  Another factor 
is operator induced -- it is known that the 50 Hz filter has some 
ringing which will change minute by minute with band noise.  Add APF on 
top of that, and the perception from one moment to another can be all 
"over the map".

I believe the test data, and look seriously for other factors that may 
influence the perception of "better or worse" when confronted with the 
facts that things (like APF) are equal.  I believe Wayne has explained 
that there are many variables (QSB, band noise) that can influence the 
final APF response, and to my mind, that is sufficient.  But there will 
be those who will remain unconvinced and will continue to use 4.16 
because the APF is "better".  There is no cure for perceptions - it is 
just something to be accepted.

Pixie dust may help, measurements will not.

73,
Don W3FPR

On 1/27/2011 7:55 PM, Bill W4ZV wrote:
>
> Don Wilhelm-4 wrote:
>>   I had a sage manager many years ago who often stated "Perception is 99%
>> of reality".  Being of a scientific mind, I had my doubts at the time
>> thinking "people will be convinced by the facts of science".
>> In later years, I have mellowed and now agree with that manager.
>> Perception IS 99% of reality!
>>
> OK let's follow your logic.  Let's assume Elecraft now wants to duplicate
> the "magical" 4.16 APF performance.  The firmware code is identical
> according to the author and the frequency response curve is identical.  What
> do you suggest they do?  Sprinkle pixie dust?
>
> 73,  Bill