[R-390] Best approach for SSB mod on R-390A

[Steve Byan]

On Jan 3, 2010, at 8:11 PM, 2002tii wrote:

> Andy wrote (regarding synchronous detection):
> 
>> (2) The classy way to do it is put a computer and DSP in the loop where the
>> oscillator is tuned with a D/A converter from the computer. The computer and
>> DSP do digital spectral analysis and look at the signals all around, then
>> decide what number (frequency) to stuff into the D/A, and consequently what
>> the oscillator frequency should be. This can be made arbitrarily smart,
>> although more often than not it is still pretty dumb. On some of the $$$
>> receivers, this "digital detector" is pretty good, like the high-end R&S
>> offerings these days. Not for the casual listener, of course. If you have
>> enough DSP horsepower, you do it all digitally with no hardware PLL at all.
>> Being a DSP-head, this is my preferred implementation, but it takes a lot of
>> careful DSP programming to make it work well.
> 
> It's an intriguing notion, and I'd love to see a good DSP 
> implementation.  I have no doubt that Andy knows lots more about DSP 
> than I do.  Even with substantial DSP horsepower, I've never gotten 
> decent results trying to implement synchronous detection in DSP, nor 
> have I seen a decent commercial DSP implementation (though I have not 
> seen an R&S DSP receiver).

I've been wanting to try a DSP Costas loop synchronous detector when I get a round tuit. The analog one in the Sony 2010 works very well.

Best regards,
-Steve

-- 
Steve Byan <stevebyan at me.com>
Littleton, MA 01460