Thought this was worthy of a thread of its own. I did a bit of research and found this, which shows where it came from: I could see them having 'heavy-duty' communicators that would be better able to withstand battle conditions. Kirk took one because it was vital to contact Spock at the appropriate time, he didn't know what he was getting into, and he wanted the type of communicator that would be the more likely to survive whatever those conditions might be.
Pretty much what I thought at the time to. It does make sense to have a combat variant (fewer bells and whistles) as well as a general purpose model.
...Similarly, the phasers of ST5/6 need not be "newer" than the sleek guns of TMP/2. And indeed we don't want them to be newer, because the sleek style continues to be seen half a century later in "Yesterday's Enterprise". Instead, the 5/6 guns with their perforated-metal, heavy-duty looks could be "submachine guns" as opposed to the "standard/dress sidearms" of the sleeker type. With fewer user extras, perhaps, what with only having one barrel rather than the four observed in ST2. But with more raw power, or more ammo, or something like that. The landing party toting the "heavier" guns on Nimbus III would certainly be excused for doing so, as they appear to be combat specialists rather than the usual collection of top officers and scientists. Kirk would just grab the same gear when tagging along. Similarly, the assassins boarding Gorkon's ship would pack the heavier guns; that our heroes would bring them along to Khitomer is slightly odd, but not inexcusable. This is unlikely to be the artist intent, but it's fun headcanon. Now, why did Saavik bring that heavier tricorder to Regula One...? It's not as if she should have been expecting either adverse weather or exceptional finds. Timo Saloniemi
Real-life armed forces have dozens of different kinds of guns in use at any given time. It makes sense for Starfleet to have many varieties of beam weapons too. Kor
Kirk may have fond memories of a Nokia in a certain stolen Corvette. He was going through an antiques phase anyway, at that point in life. anyway if they do have various weapons, Starfleet officers probably have to maintain an active qual on whatever sidearm they are expected to use, and have checked out on with their F.I.
I figure the TWOK communicators come before the Cage communicators. The Enterprise has them because they are a cadet training vessel and don't need the newest hardware. Note that when they are resupplied (implied) between TWOK and TSFS they get new phasers and communicators. I'm sure they dropped off the wounded at the nearest starbase, along with Savvik, and picked up the new equipment while doing the most crucial repairs before heading back to Earth.
It's the only thing I didn't like about The Wrath of Khan was that clunky communicator. I wondering was there an art design for the thing?
And this is supported right in TWOK itself, where the communicators the Enterprise crew uses are different than the wrist communicators the guys from the Reliant have.
According to http://memory-alpha.wikia.com/wiki/Communicator The communicators in Star Trek II were overseen by prop master Joe Longo. (text commentary, Star Trek II: The Wrath of Khan (The Director's Edition) DVD) These were essentially recycled Vietnam War walkie-talkie units, stripped of paint and coated with chrome. "It was what Paramount wanted," stated John Zabrucky, whose Modern Props facility created the communicators. "We had a really great design that we wanted to build, but they were fixed on those things." (The Making of the Trek Films, 3rd ed., p. 29)
I vaguely recall that the prop guys had to beg to be allowed to put a flip lid on them to make it look more like Star Trek. Were the Reliant wrist communicators the same ones used in TMP? I assumed they were used to be covert - Khan didn't want Kirk to know he was listening in the whole time.
...The only caveat here is that Starfleet can pack all those varieties in the same casing, at the same time, even. So why don't they? The "Type 1/2/3" thing sounds logical and natural enough: three do-all guns, only separated by size so that the bigger ones can do even more-all. And then there would be different generations of 1/2/3, and sometimes the generations would overlap. We shouldn't get much overlap aboard a single vessel, and we don't. And we shouldn't get any back-and-forth, but we get some. Unless we declare the TFF/TUC guns a "different Type 2" or "Type 2½" or whatnot, that is. Then there's the issue of how a generation gets swapped. Why do the guns (and communicators) in ST3:TSfS suddenly represent a different generation than in ST2:TWoK? (This regardless of whether we sidestep the "steady lineage" or "back-and-forth" aspect somehow or not.) Why is there a mid-adventure change in VOY? How do the logistics work there? Timo Saloniemi
TMP: http://3.bp.blogspot.com/-dCR4M3Mc_q0/UBq-zIv-whI/AAAAAAAAAHs/VuhIx3CZQT8/s1600/Comm3.jpg TWOK (replica) https://www.yourprops.com/movieprop...II-The-Wrath-of-Khan-Wrist-Communicator-1.jpg
There's also Kirk's digital watch, which almost looks like the Reliant communicator, but is different (IIRC, it's an off-the-shelf model, but that link isn't loading for me, but I'm pretty sure it's relevant).