What transmits uniform string sound (6)

I believe the answer is:

uplink

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'what transmits' is the definition.
I don't know anything about this answer so I cannot tell whether this works.

'uniform string sound' is the wordplay.
'uniform' becomes 'U' (phonetic alphabet: alpha, bravo, charlie etc.).
'string sound' becomes 'plink' (I can't explain this - if you can you should believe this answer much more).
'u'+'plink'='UPLINK'

Can you help me to learn more?

(Other definitions for uplink that I've seen before include "satellite communication" , "Communications route to a satellite" .)

I've seen this clue in The Times.

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