Episode please.
Considering that all my tapes (yes, VHS tapes) are at home and I will have very little spare time for the next few weeks, your request may take some time to meet. But the images are very definitely in my memory, including the memory of noting that he was using it like a cell phone, which in turn had sparked the memory of Nimoy on a Star Trek retrospective mentioning one day talking on his cell phone and everybody in a car passing by were pointing at him and laughing, whereupon he realized that he was like Spock using a communicator (though it's uncertain whether his placing it to his right ear had anything to do with his story).
One scene that comes to mind is in a episode that they had filmed outdoors on location and which I think involved Spock just barely being able to beam down. That could make it
Shore Leave. {strike through}Another scene was indoors on a set in which their communicators had been confiscated and disassembled so Spock had to reassemble one out of the parts while Kirk was off doing his thing.
Patterns of Force, maybe?{end strike through} Another scene was indoors on a set in which I think Spock had to convert a native communicator to work for them; I think Uhura asks why he's on such a low frequency. Might have been
A Taste of Armeggedon.
Certainly not the first pilot,
The Cage, at which time they were still in the habit of shouting into it while looking up.
Edited by dwise1, : qs
Edited by dwise1, : Patterns of Force would have been wrong