this sample of their voice mirror is from 1972 (rb)
friendly verification letter (Maarten van Delft, 1969)
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Callsigns:
HCA **
HDA **
Frequencies Voice:
9080
9802
9858
10038
10183
10495
10962
13405
13630
13908
14445
15610
16375
18171
19605
19623
20970
22770