My curiosity was aroused so I tried it using a 1.843Mhz oscillator (just because I had one) and to my surprise it seemed to work quite well.
Using a small mains transformer with two 120v primaries as the modulation transformer, and may function generator as the audio source, I was able to get reasonable looking sinewave modulated RF. Sounded quite reasonable to listen to on a receiver, at least to my ears.
However, the RF output from the oscillator is a square wave, and as such there are outputs at all odd multiples of the fundamental frequency, I would not connect this to anything more than a short piece of wire as it will vomit all over the RF spectrum.
JimB