Topband: DSP and Latency

[Bill Cromwell]

Hi Jim,

I have begun playing with soundcard SDR and DSP software. "Latency" 
varies all over the place (from config to config) and can be somewhat 
managed. The real sticking place for me is the delay between pressing 
the key (CW of course) and the beginning of the dit or dah. Again when 
releasing the key and the end of the dit or dah. When the radio is right 
in front of me, I can use an external 'sidetone' and coordinate my 
keying hand with that. I am not sure how that is handled with a remote 
station setup. Perhaps the remote user is using a local sidetone or even 
sending with a keyboard. If it's computer generated CW from the keyboard 
any 'latency' just won't matter. It's milliseconds or less - not minutes 
or hours.

Maybe this comment will help some others get a better handle on this 
'latency'.

73,

Bill  KU8H


On 03/18/2015 07:27 AM, Jim Brown wrote:
> On Wed,3/18/2015 12:14 AM, Mark van Wijk, PA5MW wrote:
>> Audio latency 'differences' can be shown in the shack already;
>
> Yes. I mentioned that A/D and D/A conversions take time. So do DSP 
> processes. The word that describes this time is latency. It is not 
> limited to audio.
>
> I had to learn about all of this more than 20 years ago, because I 
> worked in pro audio, when we began to use DSP extensively in large 
> sound systems.
>
> 73, Jim K9YC