Yes, HETERODYNES is a Scrabble word!

Letter values in Scrabble US: H 4, E 1, T 1, E 1, R 1, O 1, D 2, Y 4, N 1, E 1, S 1.

Is it a valid word?

HETERODYNES is a valid word in the official Scrabble dictionary (US), the UK Scrabble Dictionary and Words with Friends (ENABLE).

combine (a radio frequency wave) with a locally generated wave of a different frequency so as to produce a new frequency equal to the sum or the difference between the two