Model number for that unit is 20-134. I'm sure RS probably has a pdf version buried on it's support web site somewhere but it's like trying to get help out of their 800#, an exercise in futility.
You could try two different metods of getting a copy. First, try your local Shack but only ask the manager. The run of the mill sales person will be lost after the word scanner.
A second method is to email their customer support at:
May actually get a response.