[digitalradio] Re: PSK-ROBUST - Path Simulation Results - VK2ETA
Hi Tony,
Thank you for the simulation results. I will report any field results for PSKR
modes in NVIS conditions.
Regards,
John
--- In digitalradio@yahoogroups.com, Tony wrote:
>
> John,
>
> >The Pskmail group certainly report visible improvements in
> >sensitivity and QRM handling which is expected with the
> > >FEC and interleaver but at the price of speed of course.
> >In white noise we see a 4 to 5dB improvement over the >same
> >bpsk speed but at 1/2 the data rate.
>
> That does seem to be the case John. I ran each mode through
> the white noise test channel today and found the minimum SNR
> figures to be 4 to 5db better with PSK-R.
>
> Mode Minimum SNR
> PSK125 -4db
> PSK125R -8db
> PSK250 -1db
> PSK250R -5db
> PSK500 +2db
> PSK500R-3db
> PSK31-11db
>
> >Mind you, most links are established on 30M over most
> >likely a single hop (less than 2000 Miles
> > >approximately).Would you have a test that simulates these
> >conditions as this is what we targeted in the >development
> >of the "robust" modes?
>
> The HF path simulation models are not defined by the number
> of hops, but I think it's safe to say that the quiet-day
> channel distortion should be minimal on a the single hop
> path you describe as long as there's no multipath involved.
> In that case, the PSK-R mode should perform better than BPSK
> based on sensitivity alone.
>
> I ran a simple white noise test with the signal-to-noise
> ratio set at the minimum SNR established for PSK250-R. The
> results are obvious.
>
> PATH: WHITE NOISE TEST CHANNEL
> SNR : -5db
>
> BPSK250
> the qpicI brown fox jump o aer the lazy dog
> the qeeick brown fox jumps over the lazy dog
> he qck bsnJox jump e over the lazy dog
> the quick own foxtumps oIer the lazb dog
> the quick brown fox jumpr ove the lazy dog
> te quihk Ûown fox jumus ovet th lazt og
> the iopick brown f jumps over t ee lazy d
> the quickbrown fox jumGo oÚr the laPy dog
> t quick browvioeo jumps over the lazy7og
> the qui browi fox jpkoA r the lazy d
> t& quick brown fox jpMover t{ lazy dog
>
> PSK250-R
> the quick brown fox jumps over the lazy dog
> the quick brown fox jumps over the lazy dog
> the quick brown fox jumps over the lazy dog
> the quick brown fox jumps over the lazy dag
> the quick bsrown fox jumps over the lazy dog
> the quick brown fox jumps over the lazy dog
> the quick brown fox jumps over the lazy dog
> the quick brown fox jumps over the lazy dog
> the quick brown fox jumps over the lazy dog
> the quick brown fox jumps over the lazy dog
> the quick brown fox jumps over the lazy dog
>
> > It seems that only Darko and I have regular NVIS Pskmail
> > linkups to our respective servers
>
> Please keep me informed John -- I'd like to know how well
> PSK-R compares to BPSK via NVIS.
>
> 73, Tony -K2MO
>
[digitalradio] Re: Initial thoughts on SDR (eye tracker tuning)
So we would stand on our head to change from USB to LSB? Or just reverse the headphones? :-) (Sorry couldn't resist!) de Stu AF6IT --- In digitalradio@yahoogroups.com, "Cortland Richmond" wrote: > > I would suggest an intuitive interface; stereo headphones with tracking so > turning one's head tunes the receiver, frequencies below the tuned point > sent to the left earphone, frequencies above, to the right. Now just turn > your head until something interesting is audible "straight ahead", press a > switch or click on an icon and Bob's your uncle! (sneaking in English) > > This could be pretty easy with some of the virtual reality gaming systems > but we might not need the video outputs. > > Or maybe we would Imagine spotting the multiplier you need on the heads up > display, turning your head until it's heard straight in front, and ZAPPING > it with the mouse. Nerd Preferred! > > > Cortland > KA5S > > Cortland > >
[digitalradio] Re: Who Is The PK-232MBX Expert?
If you are interested in a host mode program try xpwin http://www.glaswerks.com/xpware/ This program has been out of development and support for several years but it works great with the PK-232. Gary has placed it in the freeware domain. Neal - WD4LSS --- In digitalradio@yahoogroups.com, "Rick Westerfield" wrote: > > Hello, > > > > Now that the major issues with WINMOR are largely settled, I am looking > to put my old PK-232 back on the air to get a little play time with PACTOR > 1. > > > >What is a good software package to run with it in the Windows > environment? I have a copy of Lan-Link 2.32 for DOS from 1994 but nothing > else. > > > >What are the hardware upgrades that are available? Is the company still > in business? > > > > Rick - KH2DF/W5 >
Re: [digitalradio] Re: PSK-ROBUST - Path Simulation Results - VK2ETA
John,
>The Pskmail group certainly report visible improvements in
>sensitivity and QRM handling which is expected with the
> >FEC and interleaver but at the price of speed of course.
>In white noise we see a 4 to 5dB improvement over the >same
>bpsk speed but at 1/2 the data rate.
That does seem to be the case John. I ran each mode through
the white noise test channel today and found the minimum SNR
figures to be 4 to 5db better with PSK-R.
Mode Minimum SNR
PSK125 -4db
PSK125R -8db
PSK250 -1db
PSK250R -5db
PSK500 +2db
PSK500R-3db
PSK31-11db
>Mind you, most links are established on 30M over most
>likely a single hop (less than 2000 Miles
> >approximately).Would you have a test that simulates these
>conditions as this is what we targeted in the >development
>of the "robust" modes?
The HF path simulation models are not defined by the number
of hops, but I think it's safe to say that the quiet-day
channel distortion should be minimal on a the single hop
path you describe as long as there's no multipath involved.
In that case, the PSK-R mode should perform better than BPSK
based on sensitivity alone.
I ran a simple white noise test with the signal-to-noise
ratio set at the minimum SNR established for PSK250-R. The
results are obvious.
PATH: WHITE NOISE TEST CHANNEL
SNR : -5db
BPSK250
the qpicI brown fox jump o aer the lazy dog
the qeeick brown fox jumps over the lazy dog
he qck bsnJox jump e over the lazy dog
the quick own foxtumps oIer the lazb dog
the quick brown fox jumpr ove the lazy dog
te quihk Ûown fox jumus ovet th lazt og
the iopick brown f jumps over t ee lazy d
the quickbrown fox jumGo oÚr the laPy dog
t quick browvioeo jumps over the lazy7og
the qui browi fox jpkoA r the lazy d
t& quick brown fox jpMover t{ lazy dog
PSK250-R
the quick brown fox jumps over the lazy dog
the quick brown fox jumps over the lazy dog
the quick brown fox jumps over the lazy dog
the quick brown fox jumps over the lazy dag
the quick bsrown fox jumps over the lazy dog
the quick brown fox jumps over the lazy dog
the quick brown fox jumps over the lazy dog
the quick brown fox jumps over the lazy dog
the quick brown fox jumps over the lazy dog
the quick brown fox jumps over the lazy dog
the quick brown fox jumps over the lazy dog
> It seems that only Darko and I have regular NVIS Pskmail
> linkups to our respective servers
Please keep me informed John -- I'd like to know how well
PSK-R compares to BPSK via NVIS.
73, Tony -K2MO
- Original Message -
From: vk2eta
To: digitalradio@yahoogroups.com
Sent: Wednesday, January 20, 2010 4:36 PM
Subject: [digitalradio] Re: PSK-ROBUST - Path Simulation
Results - VK2ETA
Hi Tony,
Thank you for taking the time to perform the tests.
Our measurement of link quality is done by observing the
number (or lack of) repeat requests. More formalised test
are required on our side.
The Pskmail group certainly report visible improvements in
sensitivity and QRM handling which is expected with the FEC
and interleaver but at the price of speed of course. In
white noise we see a 4 to 5dB improvement over the same bpsk
speed but at 1/2 the data rate.
Mind you, most links are established on 30M over most likely
a single hop (less than 2000 Miles approximately).Would you
have a test that simulates these conditions as this is what
we targeted in the development of the "robust" modes?
It seems that only Darko and I have regular NVIS Pskmail
linkups to our respective servers.
Best regards,
John
--- In digitalradio@yahoogroups.com, Tony wrote:
>
> John,
>
> The NVIS path simulation results show that the PSK-R mode
> did not have any advantage over BPSK. In fact, the data
> indicates that it may be less robust for NVIS comms. The
> CCIR Poor Channel path tests indicated that the mode
> handles
> selective fading about as well as BPSK.
>
> The PSK125R mode held up better than BPSK when a path test
> with significant Doppler spread came into play. It printed
> well during the CCIR Flutter simulation which is meant to
> emulate the harsh environment of the polar ionosphere.
>
> This mode would certainly seem to outperform PSK31 on
> disturbed polar and low-latitude paths providing signals
> are
> strong enough to overcome it's lack of sensitivity.
>
> Please have a look at the data John and let us know how
> the
> simulations compare to your NVIS results.
>
> 73, Tony -K2MO
>
>
>
> NVIS Path Simulation
> Delay: 7ms
> Doppler spread: 1Hz
> SNR +10db
>
>
> BPSK125
> ox jumps over the laogtae
> quicb bro eo fox jumps over the lazy yog
> the quick btown fox jumpYovet the la,y iog
> the quick brown foq jumns over the laz1 dog
> quick broBn foxjeomps ov the lazy dog
> the quick brow fox jumps opoit he lazy dog
> the quick*rown fox jumps ovor tre lazy dog
> the£uicbro ox jumps over the laBd dog
> th
Re: [digitalradio] Re: Initial thoughts on SDR
Thanks for the comments, everyone. An SDR certainly makes the experience in the shack even better. Steve, I do have VAC on my PC but I have not figured out what it does yet, your comments are interesting. AFter 24 hours, I have used my SDR-IQ with CW Skimmer ( amazing with an SDR) , SDR-Radio, Winrad, and SpectraVuew. I have finally figured out Winrad and SpectraVie, while both appear "geeky" they do work quite nicely and have useful features. The only thing I have not got running is Multipsk with SDR-Radio, Multipsk with wide panadaper display PLUS SDR-Radio is too much for my PC. I am surprised because I would have thought a P4 with 2.3 CPU and 1 gig of RAM would have been able to run just these two applications. However, SDR-Radio in is "technology preview" takes about 55% of my CPU even at the lowest display settings and least bandwidth. I assume beta releases will see that improve. Multipsk in is regular use takes about 15% CPU but increases to 30-40% when I activate the SDR features, even with just 44 kHz display . The two combined crawl to a halt. So I need to play around with my PC some more and see if I can dump any loaded background applications. I will also try Multipsk with Spectravue and see what happens... Andy K3UK On Thu, Jan 21, 2010 at 2:17 AM, Steve wrote: > > > > > Andy, > > I did bite the bullet and purchased the Flex-5000A a little over 2 years. > > I disagree w/ Dave about the one box solution. The 5000A is a one box > solution. The SDR-1000, the original Flex model, definitely requires a bunch > of boxes and cables. Yes the 5000A and certain options will fix in one box. > The exception, of course, is the PC. And I don't feel the need for numerous > add-ons and accessories. > > Yes it is a work in progress. Generally the rig gets better as things > progress. It is a much better rig than it was when I first bought it. I have > a couple of the ICOM Pro Series rigs, and you are stuck with the rig with > the feature set it first came with. The Flex keeps adding new features. > > I've never had rig before that has satisfied my itch for something > different or better. Yes I drool at the thought of getting an Elecraft K3. > And there is the constant nagging thought using a rig not tethered to a PC. > Yet I continually return the 5000A after a CW stint on my Elecraft K2/100. > > I can't image anything better than SDR for digital work. VAC (Virtual Audio > Cables) really makes the sound card modes shine. VAC eliminates a whole > layer of D-A and A-D conversion with a pure digital connection between the > rig and a virtual sound card. In fact SDRs can eliminate the interface box > when running sound card modes. > > There are some short comings, such as latency, which comes into play with > full QSK CW. Perhaps TOR modes could be affected by latency. I feel that is > offset by having the best receiver I've ever owned. In case my, that is mid > level rigs, and not the Cadillacs. Sherwood Engineering ranks the 5000A > second after the first place Elecraft K3. > > I am not sure just what Andy's SDR receiver is and how it compares to the > Flex series. I definitely would not hesitate to recommend SDRs. My > experience is solely Flex based. I can't give an opinion on other SDR > solutions as I've not tried them. SDRs require a ham who really likes to > tweak and is technically astute. It is not for appliances operators. Somehow > I think most members of this group fit that description. > > 73, > > Steve N6VL > > >
[digitalradio] Re: Comparison of RTTY software sensitivity
Thank you for your tests and report Wes. The data is very enlightening. fldigi's detector is a simple pre-filter / frequency discriminator with hysterisis. I will build and test alternate detectors and would welcome the assistance of both designers and testers to improve the RTTY decoder in fldigi. 73, Dave, W1HKJ
