What is the timing accuracy using the K3s built in RTTY via the K3 Utility or other applications that use the KY commands?
Michael Blake k9...@mac.com > On Mar 24, 2018, at 2:46 PM, Joe Subich, W4TV <li...@subich.com> wrote: > > > Unfortunately the demonstrations are not accurate representations of > real world conditions. The EXTFSK64 tests were done on a six core, > 3 GHz CPU with less than 40% CPU load. The "low end" laptop with > ETFSK was not faced with anywhere near the CPU load exhibited in most > RTTY contest situations. Neither demo stressed the USB bandwidth > (polling two rigs, and running a sound card based panadapter) or > stressed the memory capability (processing a cluster feed at > 100 > spots per minute, polling two rigs with multiple commands every 10 > to 50 msec, logging and duping QSOs from other stations on a multi- > station LAN). > > A significant number of amateurs run "hand me down" processors that > barely meet the N1MM+ minimum standard (1.6 GHz processor, 512MB/1GB > RAM) which are then "loaded to the gills" with CPU and memory intensive > processes. > > Measurements at microHAM in 2010 showed +/- 2ms jitter with EXTFSK and > an FTDI USB to Serial UART. 4 ms p-p jitter already represents nearly > 20% of a bit period - equivalent to changing the path length by more > than 700 miles within each bit - and will result in a noticeable loss > in decoder signal to noise ratio even with "strong" signals. > > 73, > > ... Joe, W4TV > > >> On 3/24/2018 1:43 PM, M. George wrote: >> This is a bit of a cross post related to Elecraft K3/K3S internal FSK >> timings generated with a USB FDTI chipset com port. I wanted to get some >> hard measured numbers in a video so I took the time to make the following >> two videos. Sorry if you are subscribed to multiple lists and get a >> duplicate or two on the video links. I do think it's interesting... if you >> can make it through my verbose videos! They don't lack for details on >> making sure I'm transparent with the setup. If anything, it will give >> something to reference as the discussion/debate continues. >> Video #1 <https://www.youtube.com/watch?v=FN0SlOHcMQw> Showing Higher End >> PC's Generating FSK Diddle Timings: >> https://www.youtube.com/watch?v=FN0SlOHcMQw >> Video #2 <https://www.youtube.com/watch?v=L48mebqLigs> (new as of this >> morning) Showing a 13 year old single core, 1.1ghz Pentium Laptop >> Generating FSK Diddle Times (32 bit Win 7 with MMTTY): >> https://www.youtube.com/watch?v=L48mebqLigs >> Max NG7M > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:Elecraft@mailman.qth.net > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to k9...@mac.com ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
