Return-Path: Received: from mtain-mj02.r1000.mx.aol.com (mtain-mj02.r1000.mail.aol.com [172.21.164.86]) by air-mb05.mail.aol.com (v129.4) with ESMTP id MAILINMB053-a5b94c2dfabf3b9; Fri, 02 Jul 2010 10:42:07 -0400 Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by mtain-mj02.r1000.mx.aol.com (Internet Inbound) with ESMTP id 0C0E538000103; Fri, 2 Jul 2010 10:42:03 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1OUhPS-0000cH-JI for rs_out_1@blacksheep.org; Fri, 02 Jul 2010 15:40:06 +0100 Received: from [193.82.116.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1OUhPR-0000c8-Vg for rsgb_lf_group@blacksheep.org; Fri, 02 Jul 2010 15:40:05 +0100 Received: from out1.ip02ir2.opaltelecom.net ([62.24.128.238]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1OUhPQ-00088H-49 for rsgb_lf_group@blacksheep.org; Fri, 02 Jul 2010 15:40:05 +0100 X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: Ak8FAOOWLUxOlkCm/2dsb2JhbACBQp4hcb8ShSQEims X-IronPort-AV: E=Sophos;i="4.53,526,1272841200"; d="txt'?scan'208,217";a="327203784" Received: from unknown (HELO laptopcore2) ([78.150.64.166]) by out1.ip02ir2.opaltelecom.net with ESMTP; 02 Jul 2010 15:39:56 +0100 From: "g3zjo" To: Date: Fri, 2 Jul 2010 15:39:55 +0100 Message-ID: <000a01cb19f4$709293c0$0202a8c0@laptopcore2> MIME-Version: 1.0 X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook, Build 10.0.2616 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.2670 In-Reply-To: <441C40E5D38B4E0FBAF138D14BCE5C5D@AGB> Importance: Normal X-Spam-Score: 0.0 (/) X-Spam-Report: autolearn=disabled,HTML_MESSAGE=0.001 Subject: RE: LF: 137.500 kHz ROS MF-1 beacon Content-Type: multipart/mixed; boundary="----=_NextPart_000_000B_01CB19FC.D256FBC0" X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: ** X-Spam-Status: No, hits=2.2 required=5.0 tests=HTML_70_80,HTML_FONTCOLOR_RED, HTML_FONTCOLOR_UNKNOWN,HTML_MESSAGE,WEIRD_PORT 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-VSS-INFO: 5400.1158/60449 X-AOL-VSS-CODE: clean x-aol-sid: 3039400c89a44c2dfabb73af X-AOL-IP: 193.82.116.20 ------=_NextPart_000_000B_01CB19FC.D256FBC0 Content-Type: multipart/alternative; boundary="----=_NextPart_001_000C_01CB19FC.D256FBC0" ------=_NextPart_001_000C_01CB19FC.D256FBC0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit I am monitoring 502kHz ROS MF1 Eddie G3ZJO -----Original Message----- From: owner-rsgb_lf_group@blacksheep.org [mailto:owner-rsgb_lf_group@blacksheep.org] On Behalf Of Graham Sent: 02 July 2010 13:33 To: rsgb_lf_group@blacksheep.org Subject: Re: LF: 137.500 kHz ROS MF-1 beacon Reply from R . MF1 ROS is 0.837053 symbols/second. If you can decode at -33dB (presumably in the reference bandwidth of 2.5kHz) that's +1.7 dB S/N in a symbol bandwidth, that in the case of 16FSK with Viterbi Decoder is possible. ROS calculate S/N for 100Hz, after tx , show's S/N for an equivalent system of 2500Hz >> CANCEL> -36 dB << (end of rx text string) From: Andy Talbot Sent: Friday, July 02, 2010 8:01 AM To: rsgb_lf_group@blacksheep.org Subject: Re: LF: 137.500 kHz ROS MF-1 beacon A thought. MF1 ROS is one symbol per second isn't it. If you can decode at -33dB (presumably in the reference bandwidth of 2.5kHz) that's -1dB S/N in a symbol bandwidth. Which I'm not sure I can believe. FSK with good Feed Solomon, or whatever, FEC needs 2 - 3dB S/N. Is the S/N calculation being a bit optimistic? The calculation in WSJT / WSPR gives an artificially high S/N value if the input bandwidth is restricted below a complete 2.5kHz's worth, and if impulsive noise is present. So could ROS be suffering some similar effect? Andy www.g4jnt.com On 1 July 2010 23:47, Graham wrote: Gary, Just a couple of db's short of a decode via the web , -36 is going some though http://websdr.ewi.utwente.nl:8901/ RX1: 21:55 @ 13.8 Hz: *[:]V-KFY:32DM5#("")EM3H#/F[_ -36 dB G .. From: Gary - G4WGT Sent: Thursday, July 01, 2010 6:35 PM To: LF Group (RSGB) Subject: LF: 137.500 kHz ROS MF-1 beacon Hi LF, My ROS MF-1 beacon is transmitting now with 3 minute timer. Frequency is 137.500 kHz (dial 136.500 kHz USB), reports & QSO attempts very welcome. ERP about 50mW. 73 Gary - G4WGT - IO83QO ------=_NextPart_001_000C_01CB19FC.D256FBC0 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable

I am monitoring= 502kHz ROS MF1

 

Eddie G3Z= JO

 

-----Original Message-----
From: owner-rsgb_lf_gro= up@blacksheep.org [mailto:owner-rsgb_lf_group@blacksheep.org] On Behalf Of Graham
Sent: 02 July 2010 13:3= 3
To: rsgb_lf_group@black= sheep.org
Subject: Re: LF: 137.50= 0 kHz ROS MF-1 beacon

 

Reply = ; from R .

 

MF1 ROS is 0.837053 symb= ols/second.  If you can decode at -33dB (presumably in the reference bandwidth of 2.5k= Hz)  that's +1.7 dB S/N in a symbol bandwidth, that in the case of 16FSK with= Viterbi Decoder is possible.

ROS calculate S/= N for 100Hz, after tx ,  show's  S/N for an equivalent system of 2500Hz   >>  CANCEL> -3= 6 dB <<  (end of rx text string)

 

 

From:= Andy Talbot

Sent:= Friday, July 02, 2010 8:01 AM

Subject: Re: LF: 137.500 kHz ROS MF-1 beacon

 

A thought. =

MF1 ROS is one= symbol per second isn't it.  If you can decode at -33dB (presumably in the= reference bandwidth of 2.5kHz)  that's -1dB S/N in a symbol bandwidth. = ;  Which I'm not sure I can believe.   FSK with good Feed Solom= on, or whatever, FEC  needs 2 - 3dB S/N.

 

Is the S/N calcu= lation being a bit optimistic?  The calculation in WSJT / WSPR gives an artificially high S/N value if the input bandwidth is restricted below= a complete 2.5kHz's worth, and if impulsive noise is present.  So= could ROS be suffering some similar effect?

On 1 July 2010= 23:47, Graham <g8fzk@g8fzk.f= snet.co.uk> wrote:

 

Gary,

 

Just a&nbs= p; couple of db's   short  of a  decode  via the  web= , -36 is going some though

 

RX1:

21:55 @ 13= .8 Hz: *[:]V-KFY= :32DM5#("")EM3H#/F[_ <CANCEL> -36 dB

G ..

 

 

From:= Gary - G4WGT

Sent:= Thursday, July 01, 2010 6:35 PM

Subject: LF: 137.500 kHz ROS MF-1 beacon

 

Hi LF,

 

My ROS MF-1 beac= on is transmitting now with 3 minute timer.

 

Frequency is 137= .500 kHz (dial 136.500 kHz USB), reports & QSO attempts very welcome.

 

ERP about 50mW.<= /span>

 

73=

 

Gary - G4WGT -= IO83QO

 



------=_NextPart_001_000C_01CB19FC.D256FBC0-- ------=_NextPart_000_000B_01CB19FC.D256FBC0 Content-Type: text/plain; name="g0nbd-500khz.txt" Content-Transfer-Encoding: 7bit Content-Disposition: attachment; filename="g0nbd-500khz.txt" RX1: 13:14 @ 0.4 Hz: G0NBD -24 dB ------=_NextPart_000_000B_01CB19FC.D256FBC0--