Re: [digitalradio] Re: New emcomm tool now available

2007-10-26 Thread Robert Thompson
On 10/18/07, Andrew O'Brien [EMAIL PROTECTED] wrote: Alas, the Linux nature of it has scared some people away. Well, given that FLTK is ported to win32, it shouldn't be impossible to port (either cleanly or using something like cygwin) to windows, for wider acceptance... I haven't yet looked at

Re: [digitalradio] Re: New emcomm tool now available

2007-10-26 Thread David
Hi Robert...thats a round about wayusually its Win programs being ported to Linux and you want to go the other way ;-) .as you can guess im a Linux opwe of course use Wine to work Win programs (if they will work)...the ECM .iso can be burnt to a CD and will work in any PC machine

Re: [digitalradio] QEX Article on HF Digital Propagation

2007-10-26 Thread Omar Shabsigh
Is there a way of getting the article for the group. It is very important. Thanks Omar YK1AO (now operating under 6C60O commemorating 60 years amateur radio in YK-land) - Original Message - From: Rud Merriam To: digitalradio@yahoogroups.com Sent: Thursday, October 25, 2007

[digitalradio] Re: QEX Article on HF Digital Propagation

2007-10-26 Thread Demetre SV1UY
--- In digitalradio@yahoogroups.com, Walt DuBose [EMAIL PROTECTED] wrote: Rud Merriam wrote: After a comment off list from Demeter I checked the Pactor specifications. It uses DBPSK or DQPSK. Why do the reports about Pactor indicate it is more robust than the QEX article would

[digitalradio] Re: QEX Article on HF Digital Propagation

2007-10-26 Thread Vojtech Bubnik
PSK31 failed, bad copy even under good SNR, with 3 ms multipath and 10 Hz Doppler. It did not do well with 2 ms multipath and 1 Hz Doppler. Since Pactor uses PSK I wondered if it would similarly fail as shown by the PSK31 results. I suspect that it handles Doppler better through frequency

[digitalradio] PSK under ionospheric flutter, was: QEX Article on HF Digital Propagation

2007-10-26 Thread Vojtech Bubnik
Why do the reports about Pactor indicate it is more robust than the QEX article would indicate? I did not read the QEX article, but I hope I learned something about PSK modulation with regard to ionospheric flutter over the years I am developing PocketDigi. 1) PSK is very efficient in white

[digitalradio] Re: RSS Feed

2007-10-26 Thread w1mnk
Andy, are you aware that RSS access to the group has been deleted? RSS is a great way to keep your inbox from getting jammed. --- In digitalradio@yahoogroups.com, w1mnk [EMAIL PROTECTED] wrote: What happened to the RSS feed. It stopped working on 10/22, and the link is gone from the home page.

[digitalradio] Re: 30m 2.8KHz wide digital signal QRM

2007-10-26 Thread Les
--- In digitalradio@yahoogroups.com, John Becker, WØJAB [EMAIL PROTECTED] wrote: not a thing here in the midwest of the US. Hi John You missed it as it switched of on the 24th but since then I have heard something on the same frequency using different modes. I'm not sure if it's been heard as

[digitalradio] How to check my PSK modulation?

2007-10-26 Thread charmquark69
Hi all, just joined the group and have been using digital modes (=PSK only) for a couple of weeks now. I've occasionally got a bad modulation report - two or three times out of maybe fifty contacts - and was wondering how I could personally check the modulation as the signal is transmitted.

Re: [digitalradio] How to check my PSK modulation?

2007-10-26 Thread Mike Blazek
Hi, Rob; You might want to consider this - http://www.usinterface.com/IMDMeter.html I'm planning on buying one. Good luck, Mike N5UKZ charmquark69 wrote: Hi all, just joined the group and have been using digital modes (=PSK only) for a couple of weeks now. I've occasionally got a bad

Re: [digitalradio] How to check my PSK modulation?

2007-10-26 Thread Heinz-Juergen Kronemeyer
On Fri, 26 Oct 2007 08:03:10 -, charmquark69 wrote: ALC set really low It's better to have no sign of ALC. If the Circuit must work, the Input is to High and the Audio could be dissorted. I use a Kenwood TS-480. My Setup of the RIG and the Audio is as follow: HF-Power Output is on

[digitalradio] Re: How to check my PSK modulation?

2007-10-26 Thread ad1y1
Hi Rob, I've found this very helpful: http://www.usinterface.com/IMDMeter.html Good luck and look for you on the bands. 73, Tony, AD1Y --- In digitalradio@yahoogroups.com, charmquark69 [EMAIL PROTECTED] wrote: Hi all, just joined the group and have been using digital modes (=PSK

[digitalradio] Re: CQ DRCC...

2007-10-26 Thread jhaynesatalumni
--- In digitalradio@yahoogroups.com, Rick [EMAIL PROTECTED] wrote: I think that I have mentioned some of this before, but unless you have a club of some kind where interested hams join and buy in to a concept, a numbering system may not be something that many will gravitate toward. I'll

Re: [digitalradio] Re: QEX Article on HF Digital Propagation

2007-10-26 Thread Rick
Something that has long been unclear to me is how can we have all these modes that work far below zero db S/N and yet the Eb/No (energy per bit relative to noise) can theoretically not go much lower than between 1 and 2 dB below zero dB according to the Shannon Limit? Then you need to take the

Re: [digitalradio] Re: How to check my PSK modulation?

2007-10-26 Thread Patrick Lindecker
Hello Rob, To measure the IMD you can transmit PSK31 or better PSK63 or 125 idling. An Ham close to you QRA will be able to give you an indication of your IMD (approximative but sufficient). Here an extract of the Multipsk help about IMD (you can do this measure with all PSK31 softs). 73

Re: [digitalradio] PSK under ionospheric flutter, was: QEX Article on HF Digital Propagation

2007-10-26 Thread Patrick Lindecker
Hello Vojteck, I think Patrick has a similar mode in MultiPSK, which limits further the character table, making the mode work with even lower S/N. You are right, I have tried PSK10 and PSKAM10. The big problem with these low speeds is the ionospheric Doppler modulation. Without any Doppler in

RE: [digitalradio] PSK under ionospheric flutter, was: QEX Article on HF Digital Propagation

2007-10-26 Thread Rud Merriam
Vojtech, Good points. After some further reflection on the article I am not sure many conclusions can be made from the material beyond its specific results about the modes covered. The various modes are to dissimilar in all aspects to draw any conclusions on whether PSK is better than MFSK, for

[digitalradio] Pactor OFDM??

2007-10-26 Thread Rud Merriam
I just read the Pactor 3 specification. I am not sure that it is OFDM. It is multi-tone but the spacing of the tones seems wider than OFDM requires. But I may be missing something in the technical definition OFDM of that differentiates it from MT. Rud Merriam K5RUD ARES AEC Montgomery

Re: [digitalradio] Re: QEX Article on HF Digital Propagation

2007-10-26 Thread Patrick Lindecker
Hello Rick, S/N in dB is measured versus a conventional noise bandwidth (3 KHz in general). This permits to compare modes against gaussia noise as you consider the signal power (indifferently of the way you modulate and the coding you use) and the noise power (the same for all modes). Eb/N0

RE: [digitalradio] Re: QEX Article on HF Digital Propagation

2007-10-26 Thread Rud Merriam
Rick, The measurement of SNR and Eb/No are two different measurements. The confusion comes because they are both cited in dB. It took me quite a lot of rereading material to clearly understand them. I dumped my understanding of it onto my web site at

[digitalradio] Test in the new ALE400 system (ALE on 400 Hz bandwidth)

2007-10-26 Thread Patrick Lindecker
Hello to all, For the ones interested by doing ALE and ARQ FAE in small bandwith (400 Hz), I have derived from the standard ALE a new ALE which bandwidth is 400 Hz (instead of 2000 Hz) and which name is ALE400. This ALE system has exactly the same functions as the standard ALE (in Multipsk)

[digitalradio] Sub Channel DQPSK

2007-10-26 Thread Rud Merriam
Would the phase distortion that can corrupt a PSK signal occur the same on a M-PSK signal? If the phase distortion affects all the sub channels then doing differential PSK among the sub channels would work where symbol to symbol DxPSK would not work. Rud Merriam K5RUD ARES AEC Montgomery

Re: [digitalradio] Re: QEX Article on HF Digital Propagation

2007-10-26 Thread Rick
My understanding is that the Eb/No is more of what you would find at the antenna terminals, without the bandwidth of the receiver? Using your data on your web site, how does this relate to say, PSK31 modulation? Would the SNR also be at zero with the 31 bps baud rate with the B/C (Bandwidth in

Re: [digitalradio] Re: QEX Article on HF Digital Propagation

2007-10-26 Thread John Becker, WØJAB
How wide is 45 baud RTTY ? At 07:52 PM 10/26/2007, Rick, KV9U wrote in part: How do you make a wider bandwidth for a given mode? Isn't the bandwidth based on the baud rate to begin with?

RE: [digitalradio] Re: QEX Article on HF Digital Propagation

2007-10-26 Thread Rud Merriam
Rick, Good questions. My only response right now is I dunno. g Back to the books. The QEX article based its results on a rate of 2% character error rate. PSK-31 with AWGN needed -11 dB. Crunching the numbers that at -10 dB you need a bandwidth of 227 Hz for 31.25 bps. At -11 dB would need

Re: [digitalradio] Re: QEX Article on HF Digital Propagation

2007-10-26 Thread Jose A. Amador
Rick wrote: Something that has long been unclear to me is how can we have all these modes that work far below zero db S/N and yet the Eb/No (energy per bit relative to noise) can theoretically not go much lower than between 1 and 2 dB below zero dB according to the Shannon Limit? That's

Re: [digitalradio] Re: QEX Article on HF Digital Propagation

2007-10-26 Thread Jose A. Amador
I thought about the same. On pactor, the doppler perturbation is 31/100 of the signalling rate, thus, results less affected, even without taking into account the FEC and QRQ strenghts that Pactor also packs along. 73, Jose, CO2JA Vojtech Bubnik wrote: PSK31 failed, bad copy even under good

[digitalradio] Digital Propagation Tests

2007-10-26 Thread Tony
All, For what it's worth, I ran several digital modes through a high-latitude ionospheric path simulator and recorded the results. The signal spread was set to 30Hz and path delay was 7 milliseconds. With these settings, the audio sounds much llike the most extreme polar path distortion and

Re: [digitalradio] Sub Channel DQPSK

2007-10-26 Thread Jose A. Amador
Rud, You can see the variations in the ionosphere as a phase modulator embedded in the channel. So, it will phase modulate whatever you attempt to get thru it. Actually, it has a phase modulator embedded for each arriving path. With differential encoding, and signalling speed higher than the