From: jannsen <0482183881-0001@t-online.de>
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	 <1Cg2XO-0ls9uC0@fwd02.sul.t-online.com> <418367773.20041219161716@web.de>
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Date: Mon, 20 Dec 2004 19:24:35 +0100
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Subject: Re: LF: MW
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Michael Oexner schrieb:
> Hi Uwe, Walter & list:
>
>
> I'm attaching a list with NDBs that are listed on 440 kHz +/- 2 kHz.
>
> FW or FA is "negative keying" of the Polish NDB DRE on 440 kHz.
>
> The term "negative keying" describes a strange situation where the
> Morse code identification of an NDB becomes "inverted". This can
> produce some strange sounding IDs, and can often be characterized by
> uneven spacing, or a very long dash, which appears between the
> callsigns. Many of the ones that are frequently heard are located in
> Eastern Europe, though negative calls have also been heard from
> Western European countries from time to time.
>
> "Negative keying" actually results from a drop (reduction) of the NDB
> transmitter's carrier level (amplitude) during the time when the
> transmitter is being keyed, i. e. transmitting the NDB's Morse code
> identification. Hence the most likely spot to find negative keying is
> to tune directly to the NDB's carrier frequency and operating the
> receiver in narrow CW mode.
>
> If you want to translate between positive and negative callsigns (or
> vice versa), you might want to try the following procedure:
>
> - Inside each Morse code character, the short period of silence
> between two adjacent "dits" or "dahs" or "dit-dahs" or "dah-dits"
> becomes a "dit".
>
> - A "dah" becomes a character separator.
>
> - The long period of silence (character separator) between two Morse
> code characters becomes a "dah".
>
> - The very long silence between two consecutive IDs of the NDB becomes
> a very long dash.
>
> Below I've tried to sketch a little graphical representation for some
> of the more frequently heard NDBs that are producing negative keying.
> The vertical line | indicates a character separator. Please have a
> look at the following examples:
>
> C       F
> - . - .|. . - .
> |. .|. - . .|.
>  I   L       E
>
> G     R     U
> - - .|. - .|. . -
> |.|. - .|. - . .|
>  E R     L
>
> and finally:
>
> D     R     E
> - . .|. - .|.
> |. . - .|. - |
>  F       A
>
>
>
> vy 73 + gd DX,
>
> Michael

Hi Michael,
thanks for the efforts you made explaining us the effect of negative keying.
best regards
Uwe/dj8wx