Belawan Radio :
this recording from 1987 brings back PKB to your ears (Andy Stumpf)
interesting QSL letter from the central office of PTT from 1976 (Frank Schüttig)
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Callsigns:
PKB
Frequencies Voice:
2182
3180
6215
6215.5
6510
6516
8746
13077
13089
Frequencies Morse Telegraphy:
474
4295
8686
12970.5
16861.7
17239.7
Frequencies Radioteletype:
8419.5
12584.5
16812
Systems used:
SITOR