DRK (Red Cross) Berlin (DEK23) :

 

here a short recording from a RTTY transmission of DEK23, calling 'DEKA2310' a mobile station (rb, 1988)
just in case you have no decoder at hand ;-)
This screenshot was made while playing the above clip in an endless loop. Started the tape for recording too late...

 

this PPC confirms a telegraph transmission from DHK86 to Michael Kunze (1978)
Joop Balneger received this PPC in 1984, confirming DEK23

 

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Callsigns:
DEK23
DHK86

 

Frequencies Voice:
3801.5
6998.5

 

Frequencies Radioteletype:
1939
3801.5
4013
6998.5
13973

Systems used:
50 Bd
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