[Elecraft] NG7M / 2 Videos on FSK RTTY timings generated with EXTFSK/64 on new and older PC's via USB FTDI Com Ports

[Michael Blake]

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
k9jri at mac.com


> On Mar 24, 2018, at 2:46 PM, Joe Subich, W4TV <lists at 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
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