[RTTY] Pactor 3 demo

[Terry]

Jim,

I would never deliberately cause interference to anyone.   I was told that
the EOC had planned to initiate a test message at that time and a few of us
listened in as we are curious about the technology and how it operates.
We were merely short wave listeners,  SWL's.

You bring up a good point about the station that originates traffic across
Winlink and their responsibilities.  Do they listen before they transmit or
just hit the button and don't care.      

I'm also learning that waveforms like PACTOR are designed to ride roughshod
over other narrow band waveforms like CW and RTTY.   Andy, K0SM describes
this in detail in one of his responses to RM11708:
http://apps.fcc.gov/ecfs/document/view?id=7521065139
Andy also points out that waveforms like STANAG specs claim as much as a
40dB narrow-band-interference advantage.
Even the ARRL acknowledges the advantage of PACTOR over CW where they say
"provides resistance to strong narrowband interference (e.g., CW)".   That's
a quote off the ARRL web site at:
http://www.arrl.org/pactor-ii

This is further proof that these waveforms do not belong in with traditional
narrow band waveforms.  

Terry






-----Original Message-----
From: Jim W7RY [mailto:w7ry at centurytel.net] 
Sent: Friday, March 21, 2014 11:51 AM
To: Terry; rtty at contesting.com
Subject: Re: [RTTY] Pactor 3 demo

So then why did you deliberately cause interference to the CW station? And
the SSB station for that matter? Although the SSB station was probably off
shore.

None the less.....

73
Jim W7RY


-----Original Message-----
From: Terry
Sent: Friday, March 21, 2014 8:27 AM
To: rtty at contesting.com
Subject: [RTTY] Pactor 3 demo

Yesterday a few of us witnessed a demonstration of Winlink using the PACTOR
3 waveform.    A simple one line email was sent from a EOC center in North
Texas to one of the Winlink stations in Central Texas around 6:00 PM CST.
The demonstration was monitored at a station in-between.   The demonstration
was done on 40 meters just above 7.100 MHz.    Prior to the start of the
demonstration, at the monitoring station, we observed an existing SSB
conversation going on just slightly off the frequency and a CW station
calling CQ on the frequency.     After the demonstration was complete the
SSB station was still there but the CW station was gone.   The transfer was
not timed but it was quick (probably two minutes) .



So  I want to retract my earlier comments about Winlink being slow.     The
demonstrated QRMing is a concern.



Thanks,



Terry





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