4c - Life-raft transmitter of German Luftwaffe used
for sea rescue purposes. Operating on 42.2 MHz, A2
only, 0.3 W output. Manufactured by Opta Radio from
the regular flexible antenna NS 4c signals could be
heard at a distance of up to 60 km from rescue aircraft
flying at 1000 m. From rescue aircraft flying at 4000 m,
NS 4c signals could be heard at a distance of 150 km.