S5  S15 M6
S16
STATUS- INACTIVE S.
  S5 from 1989 by Peter H. in Germany  
  S5 Czech OLX  
  M5 Morse OLX  
  S5 "012" from Jochen S.
  S16 OLX from Jochen 
OLX from Peter H. in Germany 
Peter H. OLX NEW
  S15 "158" from Jochen S. Winter 1981
  G5 Counting station mixing with S5 OLX  
  S5  "307"   from Jochen S. Rapid Dots

Station OLX was one of the very few stations that used a ITU registered callsign. Here is a description from Langley Pierce's book:

The second station operated by the Czech Intelligence Service (now operated by the Czech Republic) ventures into the use of ITU allocated callsigns.

Transmission Format-- Five minutes prior to transmission on the hour, this station sends in Morse code the callsign OLX in the form " VVV DE OLX OLX." Interestingly enough OLX is allocated to CETEKA, the Czech Press Agency! A three digit message identifier is repeated for five minutes beginning on the hour or half hour. This number is used to indicate whether or not the broadcast will carry traffic. if not, then the transmission ends after two minutes. In the below, 73 represents the group count.

Preamble: 424 424 424 424 424.…

Message: 73 57966 85288 30427 74322.... Papaqui 73 57966 85288 30427 74322 .... Conet.

Broadcasts, which begin on the hour or half hour, are presented in non-standard Czech by a computer synthesised female voice at 10 groups per minute. Note the nonstandard pronunciation, in particular of "yedna", which in standard Czech is pronounced as "yeden." This is believed to be a Czech military pronunciation.

1. yedna  6. shest       Papaqui - Repeat
2. dva      7. fedum      Conet - End
3. shi      8. ossum
4. shtiri   9. deviet
5. pyet   0. Nolla

Thanks to Vladimír F for the following corrections:
I have just read your article about Czech number station OLX. It was very interesting for me. I want to write you correct spellings of Czech words mentioned there in the book citation, maybe you know them.
The numbers are:

jedna (or jeden it's just the same, femininum and masculinum not a
"military pronunciation", when counting it is more common to say
jedna)
dvě (dve)
tři (tri)
čtyři (ctyri)
pět (pet)
šest (sest)
sedm (often pronounced sedum)
osm (often pronounced osum)
devět (devet)
nula

 I Repeat is "opakuji" and end is "konec".

                                                          

Broadcasts from this station used to occur with stunning regularity. month after month. However, all this was to change during the wave of revolutions that swept Eastern Europe during 1989, and it was only recently that regular schedules were partly resumed. With this reactivation, its new frequencies are shared with a Morse Code version of the same station aimed at Czech agents, possibly in Europe.

 OLX has now closed down (1996)

Here is a unique object; a QSL or confirmation card from a genuine number station,