[TenTec] DSP in CW transmit?

[Jim Brown]

On Fri, 13 Aug 2004 10:28:03 -1000, Ken Brown wrote:

>I agree with you on a lot of the points you have made.

DSP can be a double-edged sword. You can do all sorts of wild and wonderful 
things with it, but you can easily "outrun your headlights" if you aren't careful. The 
biggest issue is, indeed, latency -- the time that it takes DSP to do it's thing. I 
work in pro audio, where we use DSP extensively. In our world, 5 ms is a big 
deal, and it takes close to that to do A/D, simple processing, and a D/A to feed 
loudspeakers. 

On the other hand, when you're sending and receiving CW and trying to 
accomplish QSK, 5 ms is not a lot, and shouldn't degrade performance a lot if 
you are reasonably 1) careful and 2) skillful. That is, the processing that you are 
doing on transmit can go in sequence with the processing on receive, so as long 
as the 5ms is simply an overall delay (as opposed to being added to the 
transitions from keydown to keyup). 

Likewise, the quality of the DSP algorithms has a lot to do with how well it works. 
That seems to boil down to the DSP power available and the skill/experience of 
the programmers. There are clearly learning curves at play, and later generation 
DSP is clearly more satisfactory than earlier stuff, both in pro audio and ham 
radio.

The bottom line is that I don't think it's correct to say that just because there is 
DSP that QSK has to suffer. It MAY, but I don't think it MUST. It really does 
depend on the implementation. 

Jim Brown  K9YC