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

----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