[Elecraft] AM receive band width on K3

[Don Rasmussen]

I have the FM filter.

I learned last week after experiencing less than optimal
FM audio quality on receive that the Rx EQ is enabled
on all modes. I've never seen that on FM. 

The complicating factor is that the 8 equalizer sound
band values vary from the K3 documentation whenever the 
filter width changes (this always happens with
mode changes). 

I had Rx Eq frequency band 8 set to -16 (who needs
that much high end response), only to find that on SSB
the expected attenuation was at 3.3khz, but on FM the
attenuation was at 2.7 khz in the audio. 

I also had band 7 reduced from level. 

AM is also different with respect to the 8 Rx Eq
bands than is documented.

The spectragram displays are enligtening.

So, widen it up then make sure the Eq is correct. 



[Elecraft] AM receive band width
Erik N Basilier ebasilier at cox.net 
Sun Feb 1 17:21:39 EST 2009 

Previous message: [Elecraft] AM receive band width 


Very interesting Ron!This suggests that the radios where AM broadcast sounds good (portable radios and car radios) have built-inbass suppression and/or treble emphasis for AM, which supports the need to use the equalizer on the K3.Since the K3 is primarily for amateur communications, and many amateurs have microphones that emphasizethe highs, it makes sense for the K3 to rely on the equalizer rather than impose a non-flat response on all.(However, it helps make the case for eventually getting mode-specific equalization on the K3.)When it comes to the living-room stereo that sounds lousy on AM I guess spec-manship prevents themanufacturer from counteracting the broadcasters' roll-off, lest the expensive box look non-flat on paper.73,Erik K7TV