I couldnt find anything online regarding this, Its probably a well known fact but I didnt know.
I had heard it was an off the shelf walkie talkie at first, but the cast pointed out that it was obviously a current day object. At that point they slapped something together. That's why (please forgive me) the communicators in Wrath Of Khan are so lame. Absolutely the best Star Trek movie of all time, but the communicator and tricorder were pretty sad.
There's some for sale on a uk websiteBy the way, have you looked on eBay to see if you can find one?
The producers of the second Trek film initially asked John Zabrucky of Modern Props, Inc. to design new phaser and communicator props, but ultimately decided to reuse and refit the existing phasers from the first Trek film.
AAAAHHHHH, MY eyes!!!! It's so fugly!!!! Please put it away somewhere I never have to see it again!!!View attachment 1807029
Had to look it up, since I hadn't seen it before. I guess the Phaser 1 section was supposed to light up like the butt of the communicators.