[Elecraft] Glitches in K3 Filter response

[Joe Subich, W4TV]

The "glitch" shown in the USB plots here are the response 
on the other side of zero beat.  It will be visible if the 
DSP bandwidth is set to 0 - 4000 Hz because the IF filter 
will be placed with the "corner" at the carrier frequency 
and there will be response on the other side of the carrier 
on the filter skirt.  

The "notch" effect is due to audio response in the DSP as 
the audio frequency gets close to DC. 

73, 

   ... Joe, W4TV 
 


> -----Original Message-----
> From: elecraft-bounces at mailman.qth.net 
> [mailto:elecraft-bounces at mailman.qth.net] On Behalf Of Jack Smith
> Sent: Wednesday, January 21, 2009 7:15 AM
> To: AD6XY; 'Elecraft'
> Subject: [Elecraft] Glitches in K3 Filter response
> 
> 
> As I understand it, the K3 switches to a different input 
> bandpass filter 
> at 10.000 MHz which I believe is the source of the artifact. You will 
> get a cleaner response with K3 Filter if the test signal is 
> not at 10 MHz.
> 
> That's unfortunate, as it's easy to find a clean strong 10 
> MHz reference 
> from test gear.
> 
> Perhaps Mike should add a reminder in the help file, when he 
> completes 
> the higher priority items.
> 
> Jack K8ZOA
> 
> 
> AD6XY wrote:
> > And why not use it.
> >
> > http://n2.nabble.com/file/n2191129/27k1.jpg 27k1.jpg
> > http://n2.nabble.com/file/n2191129/2k72.jpg 2k72.jpg 
> >
> > http://n2.nabble.com/file/n2191129/400H1.jpg 400H1.jpg
> > http://n2.nabble.com/file/n2191129/400H2.jpg 400H2.jpg 
> >
> > http://n2.nabble.com/file/n2191129/13kH1.jpg 13kH1.jpg
> > http://n2.nabble.com/file/n2191129/13kh2.jpg 13kh2.jpg 
> >