Is Dr Sheldon Cooper ham radio operator?

Sheldon Cooper is a character in the very funny, science-based-sitcom "The Big Bang Theory" (aired by CBS in USA). Sheldon is theoretical physicist with a somewhat different social behavior. Episode S04E14 named "The Thespian Catalyst" was aired on Feb 03 2011 is hilarious and also of some interest of ham radio community.

In this episode, Sheldon visits his neighbor Penny to take acting classes to improve teaching skills. In the scene, Sheldon shows up with a t-shirt with a big "73" logo.

Sheldon with a big 73: is he also a ham radio operator?

(Image copyright by CBS)

Is he also a ham radio operator? I would not be surprised and I actually liked the idea:).

But a good explanation on why Sheldon likes so much the "73" comes from Yahoo Answers, quoted below:

Question from user MakeMuzik11"Sheldon Cooper's shirt had a 73 inside a circle, what is it from? From the Big Band Theory tonight, Sheldon was wearing a shirt with a 73 on it and I was wondering what show/sci-fi/movie it is from. Does anyone know!?"

Answer from user Stephanie"73, is the 21st prime number, it's mirror 37 is the 12th and it's mirror 21 is the product of multiplying, hang on to your hats, 7 and 3. Source(s): previous episode"

73 from ham radio community, Sheldon!