<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2//EN">
<HTML>
<HEAD>
<META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=ISO-8859-1">
<META NAME="Generator" CONTENT="MS Exchange Server version 5.5.2658.2">
<TITLE> Bytes/Minute</TITLE>
</HEAD>
<BODY>
<P><FONT SIZE=2>On page (17) from KN6KB's SCAMP presentation at the DCC in Nov. 2004 (<A HREF="ftp://winlink.org/SCAMP/SCAMPdccPresentation.ppt" TARGET="_blank">ftp://winlink.org/SCAMP/SCAMPdccPresentation.ppt</A>), it shows the throughput of Pactor I/II/III as measured by KN6KB using KC7WW's channel simulator.</FONT></P>
<P><FONT SIZE=2>I am unsure about his Net Bytes/Minute...if that is different that Bytes/minute?</FONT>
</P>
<P><FONT SIZE=2>The chart shows, as nearly as I can determine, a throughput of about 500 net bytes/minute for Pactor II/III and somewhat less (perhaps 250 net bytes/minute) for Pactor I.</FONT></P>
<P><FONT SIZE=2>MT63 has an advertised throughput of 200 WPM at -5 dB SNR on a poor CCIR channel as shown by KC7WW in his testing on MT63 on his channel simulator (<A HREF="http://www.johanforrer.net/hfpsk.htm" TARGET="_blank">http://www.johanforrer.net/hfpsk.htm</A>).</FONT></P>
<P><FONT SIZE=2>And the copy appears to be error free when comparied to the original "test text" and "MT63-2K -5 dB SNR text" below.</FONT>
</P>
<P><FONT SIZE=2>If I am correct, 200 WPM is 1200 CPS or 1200 bytes/second or 7200 bytes/minute. </FONT>
</P>
<P><FONT SIZE=2>Is something wrong with my math? Surely MT63 can't be 14 times faster than Pactor III at a </FONT>
<BR><FONT SIZE=2>-5 dB SNR on a poor CCIR channel?</FONT>
</P>
<P><FONT SIZE=2>Please advise.</FONT>
</P>
<P><FONT SIZE=2>Walt/K5YFW</FONT>
</P>
<P><FONT SIZE=2>==========================================================================================</FONT>
<BR><FONT SIZE=2>Test Text</FONT>
<BR><FONT SIZE=2>=====</FONT>
</P>
<P><FONT SIZE=2>The TUNER program - TUNER.COM</FONT>
</P>
<P><FONT SIZE=2>-----------------------------</FONT>
</P>
<BR>
<BR>
<P><FONT SIZE=2>1. This is a tuning aid to help get a received tone exactly on 800.0 Hz.</FONT>
</P>
<P><FONT SIZE=2>It should accept COM2, COM3, COM4 command line parameters (default is COM1)</FONT>
</P>
<P><FONT SIZE=2>and report CLIPPING (audio signal too strong for the sigma-delta circuit).</FONT>
</P>
<BR>
<BR>
<P><FONT SIZE=2>2. Unfortunately it takes too many computing cycles to incorporate this</FONT>
</P>
<P><FONT SIZE=2>in COHERENT, so run TUNER first if necessary, using an 800 Hz sinewave</FONT>
</P>
<P><FONT SIZE=2>with no modulation on it (a steady carrier in other words).</FONT>
</P>
<P><FONT SIZE=2>It may be slightly useful on a carrier that is phase-modulated, but</FONT>
</P>
<P><FONT SIZE=2>the indicator will jump around trying to follow the modulation, and in</FONT>
</P>
<P><FONT SIZE=2>any event the useful frequency range would be limited.</FONT>
</P>
<BR>
<BR>
<P><FONT SIZE=2>3. The idea is to get the little yellow line centered between the 2 green</FONT>
</P>
<P><FONT SIZE=2>lines, and staying within the green lines at all times. The nominal</FONT>
</P>
<P><FONT SIZE=2>frequency is 800.0 Hz.</FONT>
</P>
<BR>
<BR>
<P><FONT SIZE=2>4. The range of this tuning indicator is 800 Hz plus or minus 20 Hz.</FONT>
</P>
<P><FONT SIZE=2>If your signal is not ALREADY tuned to within better than 20 Hz, this</FONT>
</P>
<P><FONT SIZE=2>indicator will be useless and quite likely confusing as hell!</FONT>
</P>
<BR>
<BR>
<P><FONT SIZE=2>5. There will be some rejection of other signals outside this range, but</FONT>
</P>
<P><FONT SIZE=2>if the signal you want is weak and the interfering signals are strong there</FONT>
</P>
<P><FONT SIZE=2>will no doubt be problems.</FONT>
</P>
<BR>
<BR>
<P><FONT SIZE=2>6. If you can hear the tone, there is no substitute for zero-beating it</FONT>
</P>
<P><FONT SIZE=2>with a good crystal-derived 800 Hz sinewave sidetone.</FONT>
</P>
<BR>
<BR>
<P><FONT SIZE=2>7. TUNERC.COM is for anyone who still uses CGA graphics - I slowed down</FONT>
</P>
<P><FONT SIZE=2>the update rate to accommodate sluggish LCD displays.</FONT>
</P>
<BR>
<BR>
<P><FONT SIZE=2>VE2IQ - November '95.</FONT>
</P>
<P><FONT SIZE=2>==========================================================================================</FONT>
<BR><FONT SIZE=2>MT63-2K -5 dB SNR</FONT>
<BR><FONT SIZE=2>=====</FONT>
</P>
<P><FONT SIZE=2>The TUNER program - TUNER.COM</FONT>
</P>
<P><FONT SIZE=2>-----------------------------</FONT>
</P>
<P><FONT SIZE=2> </FONT>
</P>
<P><FONT SIZE=2> 1. This is a tuning aid to help get a received tone exactly on 800.0 Hz.</FONT>
</P>
<P><FONT SIZE=2>It should accept COM2, COM3, COM4 command line parameters (default is COM1)</FONT>
</P>
<P><FONT SIZE=2>and report CLIPPING (audio signal too strong for the sigma-delta circuit).</FONT>
</P>
<P><FONT SIZE=2> </FONT>
</P>
<P><FONT SIZE=2>2. Unfortunately it takes too many computing cycles to incorporate this</FONT>
</P>
<P><FONT SIZE=2>in COHERENT, so run TUNER first if necessary, using an 800 Hz sinewave</FONT>
</P>
<P><FONT SIZE=2>with no modulation on it (a steady carrier in other words).</FONT>
</P>
<P><FONT SIZE=2>It may be slightly useful on a carrier that is phase-modulated, but</FONT>
</P>
<P><FONT SIZE=2>the indicator will jump around trying to follow the modulation, and in</FONT>
</P>
<P><FONT SIZE=2>any event the useful frequency range would be limited.</FONT>
</P>
<P><FONT SIZE=2> </FONT>
</P>
<P><FONT SIZE=2>3. The idea is to get the little yellow line centered between the 2 green</FONT>
</P>
<P><FONT SIZE=2>lines, and staying within the green lines at all times. The nominal</FONT>
</P>
<P><FONT SIZE=2>frequency is 800.0 Hz.</FONT>
</P>
<P><FONT SIZE=2> </FONT>
</P>
<P><FONT SIZE=2>4. The range of this tuning indicator is 800 Hz plus or minus 20 Hz.</FONT>
</P>
<P><FONT SIZE=2>If your signal is not ALREADY tuned to within better than 20 Hz, this</FONT>
</P>
<P><FONT SIZE=2>indicator will be useless and quite likely confusing as hell!</FONT>
</P>
<P><FONT SIZE=2> </FONT>
</P>
<P><FONT SIZE=2>5. There will be some rejection of other signals outside this range, but</FONT>
</P>
<P><FONT SIZE=2>if the signal you want is weak and the interfering signals are strong there</FONT>
</P>
<P><FONT SIZE=2>will no doubt be problems.</FONT>
</P>
<P><FONT SIZE=2> </FONT>
</P>
<P><FONT SIZE=2>6. If you can hear the tone, there is no substitute for zero-beating it</FONT>
</P>
<P><FONT SIZE=2>with a good crystal-derived 800 Hz sinewave sidetone.</FONT>
</P>
<P><FONT SIZE=2> </FONT>
</P>
<P><FONT SIZE=2>7. TUNERC.COM is for anyone who still uses CGA graphics - I slowed down</FONT>
</P>
<P><FONT SIZE=2>the update rate to accommodate sluggish LCD displays.</FONT>
</P>
<P><FONT SIZE=2> </FONT>
</P>
<P><FONT SIZE=2>VE2IQ - November '95.</FONT>
</P>
<BR>
<BR>
</BODY>
</HTML>