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Re: LF: Spectran accuracy

To: [email protected]
Subject: Re: LF: Spectran accuracy
From: "Rik Strobbe" <[email protected]>
Date: Tue, 09 May 2000 11:22:58
In-reply-to: <[email protected]>
References: <[email protected]uk> <[email protected]>
Reply-to: [email protected]
Sender: <[email protected]>
At 17:03 8/05/00 +0000, G3KEV wrote:
Tell me Rik, why is there no qrss(LMCW) when the band is noisy like lots of
qrn/static about.
It should not be a problem if you can read signals 20 db below the noise.
My ANSWER after monitoring and experimentation with  spectran is that the qrn
chops the long dashes and you cannot be sure if it was lots of dots. This
does
not happen with normal cw because one can read words in between the crashes and conduct a qso even with a weak signal.
High static levels (thunderstroms) do not affect QRSS or DFCW as bad as
normal speed CW. Static crashes are very short (milleseconds) compared to
the 3 second dot length and appear as vertical lines on the screen, no
problem to tell them apart from the QRSS / DFCW signal that forms a
horizontal line.
During the last weeks several hams in the UK, Belgium and Germany were able
to copy the 10mW ERP signal from IK1ODO in DFCW at distances up to 1000km.
Nobody claimed to be able to hear the signal. When I copied a perfect 'O'
signal from Marco (last Friday) static noise was very bad.

If someone is interested to compare the abilities of DFCW versus fast CW I
can put up a 5mW ERP beacon that transmits DFCW (at 3 seconds/dot) and fast
CW (at 12WPM) sequentialy for one evening.

73, Rik  ON7YD



73, Rik  ON7YD


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