Back when Morse code proficiency was required for certain radio licenses, what audio frequency was used by the exam tapes, equipment or examiner that generated the Morse code audio? Was there a legal or recommended testing standard for this audio tone frequency?
The Army's code training paper tape machine, the TG-34-A, had an oscillator tuned to approximately 800 Hz according to the manual. Likely these were still used in many testing scenarios through the 1950s at least. After the proliferation of reel-to-reel tape, it would be easy to record this or record other produced Morse for testing purposes.
TG-34-A Keyer: https://radionerds.com/images/9/95/TM-11-443.pdf
I took my Amateur Extra test (20 wpm) at the Federal Building in Denver, Colorado in the 1970s, but unfortunately, I don't remember what device was used. My Novice test was done by a ham volunteer at his home in 1963. Morse came from many sources.
The ARRL widely distributed Morse code training tapes along with the book "Tune in the World with Ham Radio" in the 1970s and 1980s. (The first tape had an introduction by Jean Shepherd K2ORS, which I remember well from having heard it many times.) I got my copy around 1978, and I seem to recall that the tapes used tones of about 700 Hz. Surely the ARRL used a pitch similar to the pitch used in the FCC Morse code exams.
Some kind soul posted the audio from the tape in a YouTube video. Would someone please measure the pitch and post it in a comment? The pitch of the closest musical note will do.
In Canada there are currently no specifications for the tone frequency used for receive or send Morse tests.
RIC-1 specifies the format and duration of the test, including defining what a "word" is, and to define the spacing.
But the tones used are, in the usual Canadian Amateur manner, meant to be "negotiated between the examiner and candidate".