Return-Path: Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-df04.r1000.mx.aol.com (Internet Inbound) with ESMTP id 7533538000089; Mon, 2 Jan 2012 07:04:09 -0500 (EST) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1Rhgbl-00067m-UG for rs_out_1@blacksheep.org; Mon, 02 Jan 2012 12:03:17 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1Rhgbl-00067d-BS for rsgb_lf_group@blacksheep.org; Mon, 02 Jan 2012 12:03:17 +0000 Received: from smtpout1.wanadoo.co.uk ([80.12.242.29] helo=smtpout.wanadoo.co.uk) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1Rhgbj-0006yh-7s for rsgb_lf_group@blacksheep.org; Mon, 02 Jan 2012 12:03:17 +0000 Received: from AGB ([2.26.28.129]) by mwinf5d02 with ME id Gc361i00F2n8F8q03c36s5; Mon, 02 Jan 2012 13:03:09 +0100 Message-ID: <217817DAAB1B456F9B6E13A90A4B8944@AGB> From: "Graham" To: References: <24EF41C85642406DBC109E6B63190CBD@AGB> In-Reply-To: Date: Mon, 2 Jan 2012 12:03:06 -0000 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal Importance: Normal X-Mailer: Microsoft Windows Live Mail 14.0.8117.416 X-MimeOLE: Produced By Microsoft MimeOLE V14.0.8117.416 X-Antivirus: avast! (VPS 120102-0, 02/01/2012), Outbound message X-Antivirus-Status: Clean X-Spam-Score: 0.2 (/) X-Spam-Report: autolearn=disabled,RCVD_ILLEGAL_IP=0.234 Subject: Re: LF: OPERA The new CW / QRSS replacement data mode Content-Type: text/plain; format=flowed; charset="Windows-1252"; reply-type=original Content-Transfer-Encoding: 8bit X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.1 required=5.0 tests=MISSING_OUTLOOK_NAME autolearn=no version=2.63 X-SA-Exim-Scanned: Yes Sender: owner-rsgb_lf_group@blacksheep.org Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group X-SA-Exim-Rcpt-To: rs_out_1@blacksheep.org X-SA-Exim-Scanned: No; SAEximRunCond expanded to false x-aol-global-disposition: G X-AOL-SCOLL-SCORE: 0:2:436837376:93952408 X-AOL-SCOLL-URL_COUNT: 0 x-aol-sid: 3039ac1d40d84f019d39178a X-AOL-IP: 195.171.43.25 X-AOL-SPF: domain : blacksheep.org SPF : none Andy, Luckily I only suggested the idea ... Yes your right over the limits and with phase/frequency component , it would of been quite simple to code something that 'worked' out of the box , This was/is slightly novel as it allows a simple xtal cw tx to send data and is not really a attempt on the noise floor , but , in actuality, the data rate is very low , with quite high time and frequency stability limitations , eg , its not possible to decode the longer versions via the web-sdr system due to timing errors and a drift tolerance of +/- 1 hz in 60 mins for the longest mode (which may reduce to 30 mins) As to exact internals , well , your guess is as good as mine at the moment !. The latest download link will be posted shortly 73 -G.. -------------------------------------------------- From: "Andy Talbot" Sent: Monday, January 02, 2012 9:38 AM To: Subject: Re: LF: OPERA The new CW / QRSS replacement data mode > So what is the coding, the error correction, the decoding scheme. > Come on, in the amateur radio world there's no need for keeping such > things secret > > You can't beat Shannon - ON/OFF in a particular bandwidth with decent > FEC will always give the same performance, so what are the innards of > this one? > > Andy > www.g4jnt.com > > > On 2 January 2012 00:08, Graham wrote: >> All, >> >> >> >> After some time in development the 136/500 version of the Opera >> data mode is ready for experimental use . >> >> >> >> Download links are available from myself or Gary, G4WGT as the >> versions may change , these may also change , >> >> >> >> Users are invited to join the Opera yahoo group >> http://groups.yahoo.com/group/O_P_E_R_A_/?yguid=131323118 >> >> >> >> At the moment , spots are distributed to other OP users on line at >> the time ,. future intent is to link to the PSK-Reporting network >> and for a HF version and possible limited QSO mode , allowing >> under the noise qso's with a simple xtal tx >> >> >> >> There is a on line chat mode to facilitate tests etc >> >> >> >> The software is available for all , free to use , >> >> >> >> Happy new year to all and good luck >> >> >> >> 73-G .. >> >> >> >> >> >> >> >> >> >> >> >> >> >> OPERA The new CW/ QRSS replacement data mode >> >> >> >> There is always the assumption that all armature radio stations >> can effectively translate what ever new soundcard data mode >> that >> is coded to radio frequency.. >> >> >> >> The question I posed was ‘What about those who cannot , and only >> have CW transmission facility’s’? … >> >> >> >> Never did get a reply >> >> >> >> So after a long exchange of emails , the concept of a serial >> data >> mode that used only one tone , on/off keyed , with a eye on the >> qrss system, was finally discussed and coding work begun, an >> initial statement that in software , could be achieved a lower >> level >> of detection than that required to produce a line on a spectrum >> plot >> set the scene for a what was originally proposed to be a simple >> data mode, turned into to a race to the noise floor. >> >> >> >> >> >> OPERA >> >> >> >> Is a totally new Data / Beacon mode , profiled for the 136 and >> 500 bands , with HF possibility’s later in the project . The >> beacon >> mode is the version under test at the moment. >> >> >> >> Opera was designed as an alternative to the QRSS transmission >> system >> and provides for a limited number of characters to be transmitted >> by >> a serial single keyed tone , as is QRSS or live CW, 6 at the >> moment. >> >> >> >> It is live ‘data’ mode and there is no requirement for time >> synchronisation of the tx/rx station . >> >> >> >> The mode can be transmitted by any transmitter SSB/CW , there >> being provided a keyed tone and Comm. Port CW key interface >> >> >> >> There is a windows ‘gui’ interface and the requirement for RX >> audio feed, based round 1500 Hz , Tx audio at 1500 Hz may also be >> used to drive a audio/rf conversion , changes of Tx audio tone >> prevent collisions, and the software scans for a slot of minimum noise >> . >> to place the TX carrier in. >> >> >> >> If the CW key option is used, then the Tx frequency is selected by >> the Tx master oscillator only. >> >> >> >> Once a signal is decoded, the decode-spot is distributed to other >> web-connected users, future development will link to the >> PSK-Reporting >> network . >> >> >> >> >> >> OPERA is coded at the moment for 136 and 500 Khz and still >> under >> development. >> >> >> >> As a basic out line the system (at the moment) codes the six >> characters of the call sign and transmits them as a serial ‘pulse’ >> train using either conventional audio to RF translation , or by >> the use of a COM port and transistor keying cct that simply >> replaces the CW key , >> >> >> >> Reception, as the data is spread out along a time line , decoding >> is completed during the final stages of the transmission , due to >> this >> ,,it is not possible to include a receive progress monitor, >> however >> the system will track and decode multiple transmissions of both >> time >> bases simultaneously >> >> >> >> >> >> Transmit times are used to denote the mode >> >> >> >> 500 Khz >> >> >> >> 2 Minuets >> >> 16 Minuets >> >> >> >> 136 Khz >> >> >> >> 8 Minuets >> >> 65 Minuets >> >> >> >> >> >> >> >> S/N, The mode is capable of decoding under the noise level , >> beyond >> that of WSPR or the ROS-MF-2 system with a maximum data loss of >> 33% before the decode Fails. >> >> >> >> Opera 2 similar to WSPR >> >> >> Opera 8 6dB better than WSPR. >> >> >> >> Opera 65 9 dB better than Opera8, >> >> >> >> >> >> >