The topic has been discussed before yet no final official Nyquist AM/FM Script/Plugin was ever resolved.
The matter is so inherent to Sound Engineering that is seems absurd that even by “Audacity 3.0.5” there is not yet an official Audacity Nyquist AM/FM Script or Plugin.
Basically, all that is required is a Nyquist AM/FM Script or Plugin that, upon selection of AM or FM, produces a proper Amplitude Modulation or Frequency Modulation mono audio track from:
a) 1 x mono audio track of absolutely any audio (eg: a song) as the signal
b) 1 x mono audio track of a single sine wave frequency (any frequency within the current “project rate” range, i.e. 0Hz to 1/2 the “project rate”) as the carrier
The feature is so inherent to Sound Engineering that Audacity itself ought to code and publicly publish the plugin plus bundle it with the next release of Audacity.
Really I’ve been a professional sound engineer for decades and I never knew that.
Why does (b) have to be a separate track? Why not just generate the single sine wave within the plug-in?
For example, for AM, you can run this command in the Nyquist Prompt effect (see: https://manual.audacityteam.org/man/nyquist_prompt.html) to modulate the selected audio (mono or stereo) with a sine frequency of 100 Hz:
(mult *track* (hzosc 100))
For a different sine frequency, change “100” to the required frequency.
AM/FM Radio is inherent to sound engineering; albeit circuit driven rather than code driven.
The rough schemata I gave were based on the suggestions of others in prior related threads that never eventuated an adequate simple solution.
I agree with you that it is superior for the proposed “AM/FM Conversion” Nyguist Plugin/Script or Inbuilt Command to be applied to a single mono/stereo track and prompt for the form and frequency of the desired carrier and the option of AM or FM carriage to produce a carrier output track from a signal input track.
I will try your two suggested techniques, thank you.
However, it would still be better if Audacity created a Nyguist Plugin/Script or Inbuilt Command specific to a professional AM/FM Conversion function.