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<DIV><FONT face=Verdana><IMG class="aligncenter size-medium wp-image-110"
title="pantalla principal" height=225 alt=""
src="http://rosmodem.files.wordpress.com/2010/01/pantalla-principal.jpg?w=300&h=225"
width=300></FONT></DIV>
<DIV>
<H2 style="MARGIN: auto 0cm"><SPAN lang=EN style="mso-ansi-language: EN"><A
title="Permanent Link to New Digital Mode"
href="http://rosmodem.wordpress.com/2010/01/30/ros/"><SPAN lang=PT
style="mso-ansi-language: PT"><FONT size=4>New
Digital Mode</FONT></SPAN></A></SPAN><FONT size=4><SPAN lang=EN>
</SPAN><SPAN style="FONT-SIZE: 10pt">by José Alberto Nieto
Ros</SPAN></FONT></H2></DIV>
<DIV>
<H1>First ROS contact on 500 kHz</H1>
<P><FONT face=Tahoma>On Friday April 30, <STRONG>Graham G0NBD</STRONG> and
<STRONG>Gary G4WGT </STRONG>achieved the first contact on 500 kHz using the data
mode <STRONG>ROS</STRONG>.</FONT></P>
<P><FONT face=Tahoma>The contact between Graham G0NBD and Gary G4WGT took place
on April 30 over a 30 mile path. Initially they used ROS 500/16 mode and then
the ROS "eme" mode. During the contact power was reduced from 3 watts output to
30 mW. The antennas were 35ft top loaded whips.</FONT></P>
<P><FONT face=Tahoma>Practical Amateur antennas for this band are very
inefficient due to the wavelengths involved. It can require 50+ watts
transmitter output just to get 100 mW ERP. Efficient weak signal modes such as
ROS can help extend the range that is achieved.</FONT></P>
<P><FONT face=Tahoma>Later in the evening, Jim M0BMU called Graham G0NBD using
ROS 500/8 over a distance of 200 miles. they had a 30 minute contact with 100%
copy.</FONT></P>
<P><FONT face=Tahoma>Download the latest version of ROS from<BR></FONT><A
href="http://rosmodem.wordpress.com/" target=_blank><FONT
face=Tahoma>http://rosmodem.wordpress.com/</FONT></A></P>
<P><FONT face=Tahoma>To use ROS you just need your HF radio, a PC and a sound
card interface. Information on sound card Interfacing can be found
at<BR></FONT><A
href="http://www.southgatearc.org/articles/g0ftd/data_dummy_interface.htm"
target=_blank><FONT
face=Tahoma>http://www.southgatearc.org/articles/g0ftd/data_dummy_interface.htm</FONT></A></P>
<P><FONT face=Tahoma>and</FONT></P>
<P><A
href="http://www.southgatearc.org/news/september2007/psk31_soundcard_interface.htm"
target=_blank><FONT
face=Tahoma>http://www.southgatearc.org/news/september2007/psk31_soundcard_interface.htm</FONT></A></P></DIV></BODY></HTML>