Hi ….. but why route the key *through* the computer if you are generating the side tone off of RF…
Bob On Jul 26, 2013, at 6:16 PM, Brian Alsop <als...@nc.rr.com> wrote: > Actually computers generate probably 98% of the code during so called radio > contests. During a contest weekend it is not at all unusual for individuals > to make thousands of contacts. Computers automate the drudgery of sending > your call thousands of times and most exchanges. > > However even during these contests, the manual key has to sometimes be used > to provide corrections or handle situations not covered by "canned" messages. > > Because of the tremendous adjacent and even on frequency interference, > computers have proved incapable of decoding code with the accuracy and speed > of a human in real time. > > Brian > > On 7/26/2013 22:04, Bob Camp wrote: >> Hi >> >> There's also the time honored approach of generating the side tone off of >> the generated RF. In that case the latency to the transmitter would matter >> quite a bit. I have no idea *why* you would run the key through a computer >> in that case …. >> >> Bob >> >> On Jul 26, 2013, at 4:52 PM, Jim Lux <jim...@earthlink.net> wrote: >> >>> On 7/26/13 12:50 PM, Didier Juges wrote: >>>> There is a difference between managing the latency (as in ensuring that >>>> sound and video are synchronized, but latency itself is acceptable) and >>>> minimizing the latency as in a Morse code keyer where the operator has to >>>> manually control the generation of elements that can be as narrow as 20mS >>>> (one dit at 60 words per minute) while getting timely aural feedback. That >>>> means you need the sound to start and stop within less than about 5 mS >>>> following the key closing and opening. >>>> >>>> It is trivial to do on a microcontroller running at 1MHz but surprisingly >>>> harder to do on a 2GHz Windows machine. >>>> >>>> It is not just a matter of time stamping the key closure, you have to get >>>> the sound system starting and stopping. >>>> >>> >>> Yep. although, since the propagation path is on the order of 100 >>> milliseconds, providing feedback to the user directly from the interface >>> works quite well (e.g. generating tones directly from the keying). >>> >>> The challenge is trying generate the sidetone through Windows. But >>> really, there's no reason why you can't have a "keying box" that provides >>> the direct side tone and sends the events to the host computer. Then the >>> issue is more about keeping constant latency (or else the CW will be >>> really, really hard to copy) >>> >>> It's not like an extra 10 milliseconds of delay between keying and the >>> emitted RF waveform makes any difference at the other end. >>> >>> >>> _______________________________________________ >>> time-nuts mailing list -- time-nuts@febo.com >>> To unsubscribe, go to >>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>> and follow the instructions there. >> >> _______________________________________________ >> time-nuts mailing list -- time-nuts@febo.com >> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >> and follow the instructions there. >> >> >> ----- >> No virus found in this message. >> Checked by AVG - www.avg.com >> Version: 2012.0.2242 / Virus Database: 3209/6023 - Release Date: 07/26/13 >> >> >> > > > > > ----- > No virus found in this message. > Checked by AVG - www.avg.com > Version: 2012.0.2242 / Virus Database: 3209/6023 - Release Date: 07/26/13 > > > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
