[DSP-10] Getting Started on First DSP-10

[Perry Ogletree]

The "IF" they are talking about is a 19 KHz. or so IF created by mixing the 
receiver IF (455 KHz. in your example) down to the lower frequency.  The 
DSP-10 is designed to produce the lower IF for the DSPx or EZKit Lite. 
Unfortunately, most affordable, commercially available, DSPs will only 
handle audio frequencies.  Sound cards suffer from the same limitation.

----- Original Message ----- 
From: "Paul Black" <paulb at triode.net.au>
To: <dsp-10 at mailman.qth.net>
Sent: Wednesday, November 10, 2004 1:27 AM
Subject: Re: [DSP-10] Getting Started on First DSP-10


> I've taken the plunge and ordered the DSPx and the adaptor board from 
> TAPR. More S/N is always a good thing. As I live in Sydney Australia it 
> will take about two weeeks to arrive. But hey I'm good at waiting (well 
> not really).
>
> I was reading that the DSPx could be used with the DSP-10 program without 
> all of the RF hardware. I also read that this could be done by feeding in 
> the audio out from your receiver. As I am basically a SWL this seems to me 
> to be a good way to get started. I could then use the DSP-10 software as a 
> programmable filter to improve the quality of my received amateur 
> transmissions.
>
> As I've been searching around the internet I've also read about a program 
> called LinRad which works using a sound card. Now here is where I start to 
> get confused. The LinRad docs talk about needing to feed the IF output 
> from my receiver into the LinRad program to perform signal processing, but 
> the DSP-10 program does much the same thing by feeding in the audio out 
> from my receiver.  How does a PC soundcard manage to digitize a 455 KHz 
> signal taken directly from the IF? What is gained by directly processing 
> the IF signal? Can the DSP-10 do the same sort of thing and take an input 
> directly from the IF out of a receiver?
>
> Cheers.   Paul
>
>
> Perry Ogletree wrote:
>
>> I have used the DSPx and it works better than the EZKit Lite board.  I 
>> have not used it with the DSP-10 yet as I am still building it, but I 
>> have played with the DSPx and the EZKit Lite.  The DSPx is based on a 
>> later DSP chip in the same family as the EZKit.  You will need the 
>> customized code from the DSPx site as it uses a different ADC/DAC chip 
>> (the one the EZKit used is on longer generally available).  Also, there 
>> was a mix-up of one of the output pins that requires a minor wiring 
>> change in the DSP-10 harness.  All this is detailed via links form the 
>> DSPx site.  The overall benefit of the DSPx is improved S/N and since it 
>> has more "horsepower" it would be possible to write your own code that 
>> includes advanced modes.
>>
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