Caro Colega João Gonçalves<br><br>Já vi o manual sim e este site também.<a href="http://www.southgatearc.org/news/february2010/ros_proving_popular.htm">http://www.southgatearc.org/news/february2010/ros_proving_popular.htm</a>. Até agora só oiço Olivia nas frequencias que lá indicam. 2.2Khz é um bocado e não é propriamente um 'narrow band mode'. Mas fiquei curioso só isso. Vou experimentar um pouco de 'escuta'.<br>
<br>Cordiais 73s<br><br>JC.<br>CT2JVH<br>Lx.<br><br><div class="gmail_quote">2010/2/24 João Gonçalves Costa <span dir="ltr"><<a href="mailto:joao.a.costa@ctt.pt">joao.a.costa@ctt.pt</a>></span><br><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
Boa Tarde Jorge Capela, CT2JVH.<br>
<br>
Efectivamente existe ainda muito a clarificar sVHobre este novo software e respectivo modem.<br>
<br>
Já tentas-te ler a apresentação e fazer o download do manual: <a href="http://rosmodem.wordpress.com" target="_blank">http://rosmodem.wordpress.com</a> ..?<br>
<br>
Segundo as ultimas declarações do seu autor, o novo software ROS, trabalha numa espécie de "técnica áudio de Spread Spectrum..???", para assim não violar a regulamentação FCC sobre a matéria em HF. O que criou, imediatamente, uma série de duvidas; ler mais em: <a href="http://forums.qrz.com/showthread.php?p=1869017" target="_blank">http://forums.qrz.com/showthread.php?p=1869017</a><br>
<br>
Sendo que a técnica de spread spectrum consiste originalmente em codificar e modificar o sinal de informação executando o seu espalhamento num espectro de radiofrequências, fica-se sem saber muito bem o que é neste caso é uma "técnica áudio de Spread Spectrum" .<br>
<br>
Assim e na minha opinião e salvo futuros desenvolvimentos, o ROS pertence à grande família dos FSKs, neste caso, usando até 144 tons, não me parecendo uma nova e revolucionária técnica antes uma evolução.<br>
<br>
João Costa, CT1FBF<br>
________________________________<br>
<br>
De: <a href="mailto:cluster-bounces@radio-amador.net">cluster-bounces@radio-amador.net</a> [mailto:<a href="mailto:cluster-bounces@radio-amador.net">cluster-bounces@radio-amador.net</a>] Em nome de Jorge Capelo<br>
Enviada: quarta-feira, 24 de Fevereiro de 2010 10:41<br>
Para: Resumo Noticioso Electrónico ARLA<br>
Assunto: Re: ARLA/CLUSTER: Novo software ROS - é possível recuperar sinais a -35dB SNR!<br>
<div><div></div><div class="h5"><br>
<br>
Caro colega João Gonçalves Costa<br>
c/c Flávio PY2ZX<br>
<br>
Não sendo eu entendido em modos digitais, tenho curiosidade e queria perguntar-lhe se o ROS usa o protocolo de algum dos modos digitais já existentes (entendo que é da família dos FSKs), apenas tendo a capacidade de lidar com estas espantosamente baixas relações sinal-ruído ou é um novo modo em si mesmo (o modo 'ROS'...). Isto é, se a comunicação só é possível entre correspondentes usando o programa ROS, ou será possível por exemplo entre o HRD e ROS, por ex.? Cordialmente, obrigado.<br>
73.<br>
Jorge Capelo<br>
CT2JVH<br>
Lisboa<br>
<br>
<br>
<br>
2010/2/22 João Gonçalves Costa <<a href="mailto:joao.a.costa@ctt.pt">joao.a.costa@ctt.pt</a>><br>
<br>
<br>
ROS<br>
Enviado por: "PY2ZX" <a href="mailto:py2zx.ham@gmail.com">py2zx.ham@gmail.com</a> py2zx<br>
Dom, 21 de Fev de 2010 3:40 pm<br>
<br>
<br>
Olá pessoal,<br>
<br>
Informações na zsvhf e debate no <a href="http://qrz.com" target="_blank">qrz.com</a> sobre o novo software ROS que<br>
trabalha em Spread Spectrum. Segundo o manual é possível recuperar um<br>
sinal a -35 dB SNR!<br>
<br>
Flávio PY2ZX<br>
<br>
====================================<br>
Date: Sun, 21 Feb 2010 12:45:46 +0200<br>
From: "Derek" <<a href="mailto:derek@fotogravett.com">derek@fotogravett.com</a>><br>
Subject: Re: [ZSVHF] New Digital mode<br>
<br>
ROS is a digital communications software based on Spread Spectrum<br>
techniques. It is designed to fully optimize the power available and<br>
make contacts in the toughest conditions, for HF, EME or Meteor Scatter.<br>
The software has two Symbol Rates: 16 and 1 baud (the latter aimed at<br>
weak signals until -35 dbs of S/N) and can automatically synchronize any<br>
Symbol Rate. ROS also automatically reply to the operators that include<br>
an email in any of your messages, reporting on the parameters of the<br>
received signal.<br>
<br>
The decoding is done in real time, even in the case of 1 baud, and<br>
automatically synchronizes in frequency within a range of + -200 Hz. So,<br>
ROS simplifies the work of the operators.<br>
<br>
Hardware & Software Requirements<br>
<br>
. a SSB transceiver connected to an antenna<br>
. a computer with WindowsT.<br>
. 700 MHz or faster CPU and 32 MB of available RAM<br>
. Monitor with at least 1024 x 768 resolution<br>
. a 16 bit sound card<br>
. a serial port radio interface (to use PTT).<br>
<br>
Download manuals and software here.<br>
<br>
<a href="http://rosmodem.wordpress.com/" target="_blank">http://rosmodem.wordpress.com/</a><br>
<br>
73's ZS5Y<br>
===================================<br>
<br>
Recorded at University of Twente (Netherlands) Web SDR:<br>
<a href="http://websdr.ewi.utwente.nl:8901/" target="_blank">http://websdr.ewi.utwente.nl:8901/</a><br>
<br>
2205z ROS: PA3FWM, one hour ago has place the first offcial QSO with<br>
ROS, and it was received at this SDR. Thank you<br>
2205z PA3FWM: Ah, I had seen your repeated advertisements for your<br>
experiment, so it's nice to know that it worked out!<br>
2206z ROS: It was a historical moment. It was on 7065 LSB<br>
<br>
The First QSO<br>
18 February 2010, at 20:56 UTC took place the First Official QSO with<br>
ROS from Vitoria (Spain) to University of Twente (Netherlands) covering<br>
a distance of 1265 Km. on 7.065 Mhz. The first Ham Radio Operator to get<br>
it was EA2LE.<br>
<br>
The First Automatic Reply<br>
ROS notification: EATEST has received your Radio Message<br>
********** Please don't reply to this email ********************<br>
EATEST has received your Radio Message sent at: 21:03 UTC<br>
Received Message: 'CQ CQ CQ de EA2LE EA2LE EA2LE pse k My email is:<br>
<<a href="mailto:ea2le@ure.es">ea2le@ure.es</a>> <<a href="mailto:ea2le@ure.es">ea2le@ure.es</a>> <<a href="mailto:ea2le@ure.es">ea2le@ure.es</a>>'<br>
Operator Info:<br>
Callsign: EATEST<br>
Name: Jose Alberto Nieto Ros<br>
E-mail: <a href="mailto:nietoros@hotmail.com">nietoros@hotmail.com</a><br>
QTH: La Aljorra-Cartagena SPAIN<br>
Locator: IM97lq<br>
Station: web SDR<br>
ROS Version: 1.6.1 beta<br>
Signal Info:<br>
Symbol Rate: 16 bauds<br>
Frame Acquisition: 20/20<br>
Final Acquisition: 15/16<br>
Frequency Shift: -39,1 Hz<br>
Symbol Errors detected by Viterbi: 2/50<br>
Metric: 0 dB<br>
Vumeter Level: -8 dB<br>
CPU Usage: 20 %<br>
<br>
Download the ROS beta Software and give it a try, sounds cool.<br>
<a href="http://rosmodem.wordpress.com/" target="_blank">http://rosmodem.wordpress.com/</a><br>
Requires WinRaR or similar Rar unzipper.<br>
=====<br>
<br>
I have pretty good evidence: For starters, if you use the supplied WAV<br>
file on the website (labeled as a test sample of -35 dB S/N), you get<br>
-35dB S/N. This noise has fairly high peaks and some good troughs.<br>
<br>
I've been playing with Audacity and playing recording of the mode and<br>
noise at the same time, and I've gotten at least -31dB with fairly<br>
reliable copy. I used the white noise generator in Audacity, and read<br>
the "Metric" scale in ROS. Audacity's "white noise" is a worse-case<br>
scenario - absolutely NO nulls or peaks. I would say -31dB in this<br>
scenario is pretty darn good, considering real-life noise will wax and<br>
wain over time.<br>
<br>
-31dB is beyond WSPR mode, and ROS is real-time, whereas WSPR requires<br>
~2 minutes to decode before you can read it.<br>
<br>
KE7HQY<br>
--------------<br>
Up on the wide open spaces of VHF it may not be a problem but there just<br>
isn't enough space for digimodes that wide on HF. Fine when it's just a<br>
couple of experimenters using it, but the more who use it where are they<br>
all going to go?<br>
Julian, G4ILO<br>
--------------<br>
That's true if, and only if, the baud (a.k.a. signaling) rate equals the<br>
bit rate. According to Shannon-Hartley, the maximum error-free bit rate<br>
that can be sent on a noisy channel with a bandwidth of 2.2K Hz and a<br>
signal-to-noise ratio of -35dB is 1 bps.<br>
<br>
Shannon-Hartley formula...<br>
<br>
S/N = 10^(dB/10)<br>
S/N = 10^(-35/10) ~= 0.000316<br>
C = 2200 * (log(1 + 0.000316) / log(2)) ~= 1 bps<br>
<br>
N3RQ<br>
=================<br>
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</div></div></blockquote></div><br>