Pressure on television channel to be in charge (7)
I believe the answer is:
preside
'be in charge' is the definition.
(I've seen this in another clue)
'pressure on television channel' is the wordplay.
'pressure' becomes 'p' (scientific abbreviation).
'on' becomes 're' ('on' can be mean 'with reference to').
'television channel' becomes 'side' (I can't justify this - if you can you should give a lot more credence to this answer).
'p'+'re'+'side'='PRESIDE'
'to' is the link.
Can you help me to learn more?
(Other definitions for preside that I've seen before include "Be in authority (over)" , "Take the chair" , "Be chairman" .)