PTT Helsinki :

 

this recording from the 1960's is from the collection of Hajo Russow

 

this friendly verification letter dates from 1967 (Maarten van Delft)

 

------------------------------------------------------------

 

Callsigns:
OFB **
OFD **
OFF **

 

Frequencies Voice:
4518.5
5074.5
5343
6837
7313.5
7323.5
7378.5
8018
9177
9821.5
9888.5
10171
10441.5
11069
11648.5
12002.5
12216.5
12308
14605.5
14767
14819.8
14877.5
15477.5
17415
18261.5
19673
21769
22827
23110
23384
25065

 

Frequencies Radioteletype:
6837
10807.5
14607
15863
17427.5
19673
22985

 

Systems used:
50 Bd
SITOR