Written by John Davis and submitted by forum member Trekfan

The Tricorder made its first appearance in the episode “The Enemy Within”. The original prop was designed by Wah Chang, whose design talents also provided other familiar items like the communicator and the Romulan Bird of Prey as well as creatures such as the Gorn and the Salt Vampire. Although Wah Chang’s name was never featured in the credits, Star Trek would not have been what it was without his vital contributions.

AMT
The first mass market reproduction of a tricorder came in the “Star Trek Exploration Set” model kit by AMT in 1974. Although the kit included all three items necessary for boldly going where no man has gone before, they were drastically reduced in size and the features simplified. The soft detailing was probably influenced by the look of the equipment in the Star Trek Animated Series which was running on Saturday mornings at the time.

Remco
Remco produced role-play accessories for a number of licensees throughout the seventies and in 1975 released the Star Trek Utility Belt. This toy set included a Phaser that fired small plastic disks, a plastic flip-open Communicator and, of course, a Tricorder. All items were kid sized, and again looked more like their animated counterparts.

Mego
Mego was THE toy company in the seventies, producing action figures and playsets for everything from Batman to The Dukes of Hazzard. It didn’t take long before they acquired the license for Star Trek, producing a very successful range of characters and accessories. 1976 saw the release of Mego’s interpretation of a tricorder, which was little more than a cassette recorder in the general shape of the original prop. A flip-up hood revealed the controls, and the middle section opened to insert the cassette. Included was a tape with thirty minutes from “The Menagerie” on one side and blank on the other side to record your own Star Trek adventures. Far from an accurate prop, it was certainly enough to keep younger Star Trek fans very happy.

Fan Produced
Through the late seventies and eighties, there were several fan produced Tricorder
props available at conventions and through mail order companies (mostly unlicensed),
but no further mass market attempts were made until Playmates picked up the Star
Trek license in 1992.

Playmates
Starting with action figures and accessories from Star Trek: The Next Generation, it didn’t take long for them to move into Classic Trek territory. After making adequate versions of the Phaser and Communicator, the Playmates designers suddenly stumbled with their release of the Tricorder - it was half the size it needed to be!

Master Replicas
At long last, a licensed Tricorder has been released that not only matches the physical specifications of the original prop, but goes one further with electronic functions and accurate sound effects. Thank you, Master Replicas, for your care, dedication, and precision in recreating one of the most iconic props of all time.

This part added by forum member Mobius303

Mr Chang made some great contributions to the props. Perhaps the biggest was
making them all consistent in look and function. For example the Moire Rings were on both the Communicator as well as the Tricorder. The side rails and midplates on the
three big props all made them look like pieces of equipment that belong together. It
is my belief that the Moire rings were actually some kind of data storage device for the
equipment. If you look closely you can see that the disks (first one anyways) could be removed. We never saw this feature on film but it is nice to know they were thinking ahead. There is a great article on the original tricorder as well as the other props at: http://www.saucersoverhollywood.com