At 11:26 AM 1/7/2007, W7CE wrote: >----- Original Message ----- > > At 08:41 AM 1/7/2007, K0MV wrote: > >>Those of you who have Tivo boxes will recognize this. > >> > >>The feature is a continuous recording of the last 5 minutes of the > >>received signal. You can rewind and go back to see if you copied that > >>DX callsign correctly, or maybe try a narrower filter. > >> > >>Regards, > >>Chuck k0mv > > > >I suggested this TIVO-like replay feature while chatting just before the >11/1 Town Meeting. I'd like to see it work just like the TIVO replay >feature: a pre-determined amount of recorded history in a moving window >(circular buffer) with the ability to rewind, fast-forward, slow-motion or >just go back 15 seconds at a time. Additionally, when going in slow-motion >the audio could be scaled to normal pitch. This would really help when >trying to pull out that weak one that insists on sending CW at 30+ WPM. I >think the IF should be recorded so that filters can be adjusted during >playback. Total size of the recording window should be adjustable. At 192 >KHz sampling, the storage requirements are not that large. Just use a file >for the buffer. My TIVO box maintains a 30 minute buffer for two separate >channels. Doing the same here requires a lot less storage. > >How would I use it? Primarily for getting the callsign of a weak station in >a pileup (usually on 160M or 80M), but I can also see using it for >weak-signal VHF/UHF work. I can't imagine using it much in a contest. >There usually isn't time for that kind of instant playback, unless you're >much better at multi-tasking than I am.
You use it for, ahem, post contest "log checking". Hey, at least the signal was received over the air, which is a lot more sporting than "reading the callbook". But I see all these things as just sort of gradations of various strategies.. There are a number of CW decoders out there, and for the typical contest exchange, they'd probably work pretty well. Over lunch, we've talked about how it would be possible to build a piece of software that would do multiple parallel sequential decoding to dig out the weak signals (find the strong ones, subtract them, etc.), and while you're at it, totally automate the exchange (QSL, UR 59, PLS RPT ALL). Just think, you could sleep while your cluster computer racks up the big points in the contest for you. Instead of losing sleep during the contest, and spending all those hours refining your contesting skills, you'd be losing sleep in the months before, trying to get all that signal processing software working. This would, of course, be just another instance of a Cognitive Radio... Conceptually, it's not much different than playing chess vs writing software to be successful at chess. Neither is easy, they're just different, and would interest different types of people. What's cool about the new crop of SDR peripherals (SDR1000 being but one) is that they actually make stuff like this easier, because they DO provide a "closer to the air" audio stream, as opposed to something that has had a lot of analog processing. Jim, W6RMK _______________________________________________ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://www.mail-archive.com/flexradio%40flex-radio.biz/ FlexRadio Homepage: http://www.flex-radio.com/ FlexRadio Knowledge Base: http://kb.flex-radio.com/
