Originally Posted by
Tee Emm
Correct me if I am wrong (story of my life) but I believe the genesis of transponder codes was during WW2 when they were known as Identification Friend or Foe (IFF for short). In the hope that Germans listening in to RAF frequencies could be fooled, various code names were invented. Thus the code name for IFF was "Parrot." And the code name for transmit was "Squawk."
When RAF controllers wished to tell pilots to switch to a new frequency they would say "Squawk Channel Able
If they told the pilot to switch off his transponder the code word was "Strangle" Thus "Strangle your Parrot"
Almost right.
Listening to the radar pulse from IFF sounded like a squawk noise and this was the 'colloquial' term used by the engineers. It stuck and has been used since then in R/T to tell an aircraft to switch on its transponder. The wartime R/T that was used to obfuscate what was being talked about was Parrot. The exchange 'Strangle Parrot' -- response 'Polly's Dead' were used. But we are back in the times of 'What's your oranges?' ' Oranges Sweet'
