[Elecraft] APF question

[Bill W4ZV]

VE3WDM wrote:
> 
> When using the APF function on my K3 I am getting a real tinny sound to
> the point were it is difficult to understand the code. I was wondering if
> settings were ok. 
> Here is what I do.
> 1. Zero beat the CW signal with the spot feature and tuning is set to
> fine.
> 2. The filter is set at either 400hz or 350hz
> 3. The APF setting is a .60 I also adjust this setting to see if the audio
> improves but it does not seem to. 
> 4. I do try to fine adjust the VFO (fine setting) for the signal to jump
> out. All that happens is it gets more tinny. 
> Any suggestions?
> 

APF is not intended for signals much stronger than the noise floor.  On
stronger signals it sounds tinny because its 30 Hz filter is on the verge of
ringing.  If you can hear a CW signal Q5, you don't need or want APF.  It's
intended for the 339 and 449 signals buried in noise.  It can bring these
signals to Q5 but must be peaked carefully because the BW is so narrow.

73,  Bill

--
View this message in context: http://elecraft.365791.n2.nabble.com/APF-question-tp6986325p6986495.html
Sent from the Elecraft mailing list archive at Nabble.com.