Return-Path: Received: from mtain-mc11.r1000.mx.aol.com (mtain-mc11.r1000.mx.aol.com [172.29.96.83]) by air-mf05.mail.aol.com (v129.4) with ESMTP id MAILINMF053-8beb4c5285a668; Fri, 30 Jul 2010 03:56:23 -0400 Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by mtain-mc11.r1000.mx.aol.com (Internet Inbound) with ESMTP id 0D09E380000C5; Fri, 30 Jul 2010 03:56:19 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1OekQl-00050H-4y for rs_out_1@blacksheep.org; Fri, 30 Jul 2010 08:54:59 +0100 Received: from [193.82.116.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1OekQk-000508-KR for rsgb_lf_group@blacksheep.org; Fri, 30 Jul 2010 08:54:58 +0100 Received: from mail-bw0-f43.google.com ([209.85.214.43]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1OekQj-0005kf-Em for rsgb_lf_group@blacksheep.org; Fri, 30 Jul 2010 08:54:58 +0100 Received: by bwz13 with SMTP id 13so716540bwz.16 for ; Fri, 30 Jul 2010 00:54:56 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:received:received:in-reply-to :references:date:message-id:subject:from:to:content-type; bh=vYuvGFJUzrmhpmBXLIf0Jdwe7ZwLKi5pB2Jjng+4J94=; b=oyCrpR0CyrX97T1JHU/6EqwM4GgHitdP1KhSTnY0fkoJ9DKVFs254b3UriZov8BCDa 6TQmGOvQQPY2R8XZSZONQORd6xaXnUnCCUbVo5lkRuAgzyeuWLbYtZzthEBmM2CoMn2Z ArhMpdvXsX/NTX882fGhbODrFA4KKJTZ9tcHM= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type; b=T9pYAZDCHHXR5OekyqaEosU5XS+jJecPF3EmKL0COpR5lBInsMjtx8Do2SHV7NGZ0i gP3w+3z2mz73uoUVzZx2HoyUbfDYNw28RLDeUT+kxrIPRKAOaSOY7vVrRm1e/XuJJ6EM SNo3l3f3S5p/Yiar8nl+ng+6xd3+k6wzoBLG8= MIME-Version: 1.0 Received: by 10.204.136.71 with SMTP id q7mr877204bkt.111.1280476496090; Fri, 30 Jul 2010 00:54:56 -0700 (PDT) Received: by 10.204.122.148 with HTTP; Fri, 30 Jul 2010 00:54:56 -0700 (PDT) In-Reply-To: References: <4C51FA69.1030202@iup.uni-heidelberg.de> Date: Fri, 30 Jul 2010 08:54:56 +0100 Message-ID: From: Roger Lapthorn To: rsgb_lf_group@blacksheep.org DomainKey-Status: good (testing) X-Spam-Score: 0.0 (/) X-Spam-Report: autolearn=disabled,HTML_MESSAGE=0.001 Subject: Re: LF: Digital modes comparison Content-Type: multipart/alternative; boundary=0015174befdcb155b8048c962a62 X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.5 required=5.0 tests=HTML_20_30,HTML_MESSAGE 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-AUTHENTICATION: mail_rly_antispam_dkim-m229.1 ; domain : gmail.com DKIM : pass x-aol-sid: 3039ac1d60534c5285a30075 X-AOL-IP: 193.82.116.20 X-Mailer: Unknown (No Version) --0015174befdcb155b8048c962a62 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Presumably "QRSS very very slow" is better still, but here this issue is= the time to get data through. Andy, I assume that you're saying WSPR or JT4A give the best "data per bandwidth per given time"? 73s Roger G3XBM On 30 July 2010 08:17, Andy Talbot wrote: > Try WSPR at 6Hz bandwidth or JT4A at less that 20Hz. They are both MS= FK > constant envelope schemes. > > > Andy > www.g4jnt.com > > > 2010/7/29 Stefan Sch=E4fer > > Andy, LF, >> >> Which digital mode could be most suited for a band where one has just= an >> antenna bandwidth of some Hz? You know what i mean... And what could be= the >> "gain" compared to DFCW-600. Gain means here, how far(er) could it be >> detected, not how much more information can i transmit within the same= time. >> >> 73, Stefan/DK7FC >> >> PS: I see that e.g. JT65 needs abt 200 Hz, so this NOT suited! >> >> >> Am 29.07.2010 23:07, schrieb Andy Talbot: >> >> It would be very interesting to see those figures normalised to a const= ant >> data rate / bandwidth. For example, PSK31 shown at -10dB is identical= to >> PKK63 at -7dB - well it would be, its the same modulation, just faster.= Ie >> plot Bits/second/Hz vs. Eb/No, then stick the Shannon limit on the grap= h and >> see which lie nearest. >> >> The fact that JT65 is at the top is probably because it sits at around >> 0.27 chars / second, or something like 1.2 B/s. Although even after >> normalisation, it would no doubt still score well up. >> >> >> Andy >> www.g4jnt.com >> >> >> On 29 July 2010 21:48, John Bruce McCreath wrot= e: >> >>> Hello LFers, >>> >>> I found this while web browsing....interesting reading and Mal's >>> favourite mode isn't top dog. >>> >>> >>> http://kb2hsh.blogspot.com/2010/05/capabilities-of-weak-signal-digital= .html >>> >>> I was looking for sites having info about digital modes on 1,800 kHz.= and >>> lower frequencies. >>> >>> 73, J.B., VE3EAR >>> >>> LowFER Beacon "EAR" >>> 188.830 kHz. QRSS30 >>> EN93dr >>> >>> >>> >>> >>> >>> >>> >> > --=20 http://g3xbm-qrp.blogspot.com/ http://www.g3xbm.co.uk http://www.youtube.com/user/g3xbm G3XBM GQRP 1678 ISWL G11088 --0015174befdcb155b8048c962a62 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Presumably "QRSS very very slow" is better still, but here this= issue is the time to get data through. Andy, I assume that you're say= ing WSPR or JT4A give the best "data per bandwidth per given time&quo= t;?

73s
Roger G3XBM

On 30 July 2010= 08:17, Andy Talbot <andy.g4jnt@googlemail.com> wrote:
Try WSPR at 6Hz bandwidth=A0 or JT4A at less that 20Hz.=A0=A0 They ar= e both MSFK constant envelope schemes.
=A0
2010/7/29 Stefan Sch=E4fer &l= t;scha= efer@iup.uni-heidelberg.de>

Andy, LF,

Which digital= mode could be most suited for a band where one has just an antenna bandwi= dth of some Hz? You know what i mean... And what could be the "gain&q= uot; compared to DFCW-600. Gain means here, how far(er) could it be detect= ed, not how much more information can i transmit within the same time.

73, Stefan/DK7FC

PS: I see that e.g. JT65 needs abt 200 Hz, so= this NOT suited!


Am 29.07.2010 23:07, schrieb Andy Talbot:=20
It would be very interesting to see those figures normalised to a con= stant data rate / bandwidth.=A0 For example, PSK31 shown at -10dB is ident= ical to PKK63 at -7dB - well it would be, its the same modulation, just fa= ster.=A0=A0 Ie plot Bits/second/Hz vs. Eb/No, then stick the Shannon limit= on the graph and see which lie nearest.
=A0
The fact that JT65 is at the top is probably because it sits at aroun= d 0.27 chars / second, or something like 1.2 B/s.=A0 Although even after= normalisation, it would no doubt still score=A0well up.
=A0
On 29 July 2010 21:48, John Bruce McCreath <weazle@hurontel.on.ca> wrote:
Hello LFers,
I found this while web browsing....interesting reading and Mal's= favourite mode isn't top dog.

http://kb2hsh.blogspot.com/2010/05/cap= abilities-of-weak-signal-digital.html

I was looking for sites= having info about digital modes on 1,800 kHz. and lower frequencies.

73, J.B., VE3EAR

LowFER Beacon "EAR"
188.830 kHz.= QRSS30
EN93dr











--
http://g3xbm-qrp.blogspot.com/
http://www.g3xbm.co.uk
http://www.youtube.com/user/g3xbm
G3XBM=A0 =A0 GQRP 1678=A0 =A0 =A0 ISWL G11088
--0015174befdcb155b8048c962a62--