once you have heard this sound, you keep it in memory for lifetime
(Willi Passmann, 1975)
in 1965, Maarten van Delft received this letter for reception
verification
a nice and detailed QSL card
from 1970 (rb)
funny: without knowing about each other, and with a difference
of 5 hours and 100 km, Hans Friedrich Dumrese listened to IBF
the very same day
The National Electrotechnical Institute switched off their transmissions in 1991, but as commemorative act they had in November 2011 a special transmission:
the announcement was the same as before, but without morse and
time-clicks (rb)
reports were awarded by this nice QSL (Mauro Giroletti)
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Callsigns:
IBF
Frequencies Voice:
5000