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

Rick WA6NHC wa6nhc at gmail.com
Sun Mar 25 16:37:15 EDT 2018



On 3/25/2018 12:15 PM, Joe Subich, W4TV wrote:
>
> Even today the number/percentage of amateurs using liquid cooled, hex 
> core 3 GHz i7
> processors like you used for your first "demonstration" is exceedingly
> small.  As I have told you multiple times, based on my support work
> the average amateur system is something like an 2.4 GHz Core2Duo with
> 1 - 4 GB of RAM and typically a single USB Root Hub to serve CAT, CW,
> FSK, digital sound card, *and* software panadapter.
>
> *NONE* of your demonstrations showed that level of system under *FULL*
> load.  Your first demonstration may have been running rig control and
> software panadapter but it wasn't processing a cluster feed at contest
> rates (your panadapter was clearly visible with only one or two signals
> on the band) and your CPU did not exceed roughly 40% utilization. Your
> second demonstration did not include rig control, panadapter or cluster
> yet by, your own measurements, had more than 10% *per bit* jitter which
> is enough according to Chen to reduce SNR by several dB.

Joe, I suspect you're selling the ham community short.  While 'thrifty' 
(ok, most hams are just plain cheap but it IS a hobby in a world of life 
issues) there is a LOT of computing power available in the used market.  
One can pick up an I-5/6/7 for a pittance and memory is dirt cheap.

I guess I'm on the bleeding edge for once.  A couple years ago I 
assembled a system specifically FOR the station; it's wasn't free but it 
also didn't break the bank.  It's a 4 GHz (slightly overclocked to 4.3 
GHz and air cooled) I-7 with 32 GB of ram and the C: drive is a 520 GB 
SSD M3 chip mounted on the mboard (multiple data paths).

NOTHING slows it down (although Windows tries), as intended.  I've only 
found one ham program that actually causes load levels to rise but it's 
short duration and never maxed out.  It wasn't a repurposed system, it 
was created to last a long time.  Not even Photoshop causes a stutter 
(and that is a demanding suite of software).

It also captures weather data, produces a live wx web page, collects 
images from 4 critters cams and puts that on another live video web 
page, along with the usual mundane tasks like email and browsing. (What 
I DO need is fast Internet but I didn't move to North Idaho for the 
Internet ;-) )

I use 'real' serial ports, not USB for station control and FSK data.  
It's all in the details.  I've had poor performance from USB not from 
path overload but because it's sensitive to RFI at the worst moments; 
serial is more bullet proof.

So I agree Joe, as often as you're spot on, that your data may be a bit 
dated on this topic.  I'm positive I'm not the only one using more than 
a dual core CPU in the station as most of the software these days (if 
not the OS) requires better performance.  A dual core for ham stations 
these days is self-flagellation.  My only use for one is to play music 
into the home theater, Skype with the family gathered or stream web 
based video on the large flat screen.  Every tool has a use but the days 
of dual core for stations are long over.

Jitter is a documentable problem, it exists for a variety of reasons 
(not always the path used to transfer data), some of which are not 
resolvable unless taken to extreme measures.  In severe cases, a move to 
AFSK is an acceptable alternative and easily managed.

Let's move on and end this thread please.

Rick nhc



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