https://rbn.telegraphy.de/activity/PE1NNZ
RBN activity of PE1NNZ
Summary of the Morse code activity of PE1NNZ over the last year
rbnactivity
https://www.pe1nnz.nl.eu.org/
pe1nnz.nl.eu.org
some thoughts on digital signal processing in amateur radio ...
nleu
https://www.pe1nnz.nl.eu.org/2009/03/multiband-si570-wspr-beacon.html
pe1nnz.nl.eu.org: Multiband SI570 WSPR beacon
more info here (login account required): http://wsprnet.org/drupal/node/2043
nleumultibandwsprbeacon