a recording from 2011 of
ROT's morse signal, with Kassel *KSL
in the background (rb)
here is a multi-station-verification
letter (Willi Passmann, 1976)
this communication sheet
from Rotterdam airport dates from 1979 (Rudy van Dalen)
Rudy van Dalen received this QSL letter in 1980
look at the nice QSL card
from the aviation administration (Ary Boender)
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Callsigns:
ROT
Frequencies Morse Telegraphy:
350.5