[Elecraft] Impossible mission? USB with the 13khz filter for PSK31on Digipan

[Thomas Tumino]

OK now I am a little confused.
I just took a look at the audio output from the K3 in AM and FM, and I cannot get more then the 4Khz out just as you said.
 
Typical FM bandwidth is 5Khz, so the DSP really needs to be changed as in its current state the K3 is chopping off 1Khz of received signal in FM, or 20% of the bandwidth.  I believe the situation is even worse for AM....which I guess is what you were alluding to.
 
Is there a way to completely disable the DSP?  Is there a reason the rig was designed this way?  It seems so out of character for an otherwise fine quality rig.
 
73,
Tom

--- On Thu, 1/29/09, Joe Subich, W4TV <lists at subich.com> wrote:

From: Joe Subich, W4TV <lists at subich.com>
Subject: RE: [Elecraft] Impossible mission? USB with the 13khz filter for PSK31on Digipan
To: thomastumino at yahoo.com, elecraft at mailman.qth.net
Date: Thursday, January 29, 2009, 5:39 PM

> I wonder why they setup the radio that way....thats
> a limiting factor when using programs like CW skimmer
> which like Digipan decodes a 3Khz+ swath of CW stations
> all at once......

It looks like DigiPan will run/display up to 5500 Hz - 
that doesn't seem to be a significant benefit above 
the K3's 4200 Hz limit.  

CW Skimmer requires separate I/Q sources in order to do 
broadband decoding and that's not available from the 
K3 audio interface (Line Out).  

I don't know the DAC clock rate is but if possible 
it would be nice to be able to sretch the response to 
5500 or 6000 Hz for occasional use with AM/SWL/etc. 
However, I'd rather see per mode EQ and some extensions 
to the CAT interface first. 

73, 

   ... Joe, W4TV 
 



> -----Original Message-----
> From: Thomas Tumino [mailto:thomastumino at yahoo.com] 
> Sent: Thursday, January 29, 2009 4:35 PM
> To: elecraft at mailman.qth.net; lists at subich.com
> Subject: RE: [Elecraft] Impossible mission? USB with the 
> 13khz filter for PSK31on Digipan
> 
> 
> > Unfortunately, despite specifically enabling the KFL3B-FM
> > 13Khz filter in USB mode, I cannot get 13Khz of bandwidth in 
> > USB receive.  As a matter of fact, I cannot seem to get much 
> > more then 4Khz of receive in USB receive mode. 
> 
> You will not see more than 4 KHz of audio in any mode.  The 
> DSP includes a "brickwall" cut-off at 4200 Hz in SSB, DATA, 
> AM and FM with a lower (2800 Hz) cutoff in CW. 
> 
> 73, 
> 
>    ... Joe, W4TV 
> 
> Joe,
> I wonder why they setup the radio that way....thats
> a limiting factor when using programs like CW skimmer
> which like Digipan decodes a 3Khz+ swath of CW stations
> all at once......
> 73-Tom-N2YTF   
>  
> 
> 
> 
> > -----Original Message-----
> > From: elecraft-bounces at mailman.qth.net
> > [mailto:elecraft-bounces at mailman.qth.net] On Behalf Of Thomas Tumino
> > Sent: Thursday, January 29, 2009 12:59 PM
> > To: elecraft at mailman.qth.net
> > Subject: [Elecraft] Impossible mission? USB with the 13khz 
> > filter for PSK31on Digipan
> > 
> > 
> > Hi there,
> > 
> > I am running my K3 with Digipan computer software on PSK 31.
> > I also have a full complement of 5 filters in the K3, with 
> > the widest being the KFL3B-FM 13Khz filter.
> > 
> > Because Digipan can receive many PSK signals at once
> > (Multichannel Window), I would like to set my K3 to receive 
> > USB through the 13Khz filter.  
> > 
> > Unfortunately, despite specifically enabling the KFL3B-FM
> > 13Khz filter in USB mode, I cannot get 13Khz of bandwidth in 
> > USB receive.  As a matter of fact, I cannot seem to get much 
> > more then 4Khz of receive in USB receive mode.  I can get the 
> > XFIL display to tell me I am receiving through the 13Khz 
> > filter, but only about 4Khz of audio will pass through 
> > (perhaps the DSP??).
> > 
> > Am I missing something here, or is this just an oversight in
> > firmware design?  Multichannel simultaneous receive of a 
> > massive chunk of bandwidth is a great feature of Digipan that 
> > I would love to take advantage of with my K3.  
> > 
> > Does someone know how to receive USB at a 13Khz bandwidth 
> with the K3?
> > 
> > 73,
> > Tom-N2YTF
> > 
> 

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