​​Hello Markus,

FSKing the carrier a few Hz would be easy to implement and easy to detect.

One option would be DFCW another would be WSPR. For both you would need no more than arduino board (or something similar) that only cost a few Euro.

73, Rik  ON7YD - OR7T

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Van: [email protected] <[email protected]> namens Markus Vester <[email protected]>
Verzonden: zaterdag 10 november 2018 16:54
Aan: [email protected]
Onderwerp: Re: LF: 1476 kHz AM

 

Many thanks again also to Rik, Ian, Stefan, Mauro, Ewald for your fine observations and suggestions, both on behalf of Ralph and from myself.  I can say that we are overwhelmed by the number of positive responses.

Yes some type of subaudio ID on the carrier would surely make sense. I had thought of a phase modulation scheme (perhaps similar to the 162 kHz timecode), but at this speed it may have a negative impact on synchroneous AM demodulators which use a PLL to regenerate the carrier. A very slow (several seconds) but characteristic frequency modulation may indeed be the best option.

Best 73,
Markus


-----Ursprüngliche Mitteilung-----
Von: Mauro Giroletti <[email protected]>
An: rsgb_lf_group <[email protected]>
Verschickt: Sa, 10. Nov. 2018 16:35
Betreff: R: RE: LF: 1476 kHz AM

Hi,

reception  1476khz my locator JN45nk .

73

Mauro Ik2GFT

----Messaggio originale----
Da: [email protected]
Data: 10-nov-2018 15.59
A: <[email protected]>
Ogg: RE: LF: 1476 kHz AM

The carrier is right now audible and visible on a
battery powered portable SDR (Reuter Pocket)
with just a small active ferrite antenna.

73
Clemens
DL4RAJ