So transmit these intermittently for secretive organisation (5)
I believe the answer is:
stasi
'secretive organisation' is the definition.
I don't know anything about this answer so I can't tell whether it can be defined by this definition.
'so transmit these intermittently' is the wordplay.
'these intermittently' indicates alternate letters.
'so'+'transmit'='sotransmit'
The alternate letters of 'sotransmit' are 'STASI'.
'for' acts as a link.
Can you help me to learn more?
(Other definitions for stasi that I've seen before include "Force behind Wall" , "Former German security service" , "Force that spied" , "Secret police of the former German Democratic Republic" , "old secret service" .)