"Falcon"

I noticed some time ago that I pronounce the /f/ phoneme in the word "falcon" differently to in every other English word. The F is somewhere between a proper /f/ and a /v/. Honestly it sounds more like a /v/, but it has an element of /f/ that distinguishes it from "vulcan". The lower lip is pulled back more and there's more aspiration than a /f/. I've been listening to the word whenever it comes up. This strange VF hybrid speech sound is always there in native speakers. Watched the Empire Strikes Back just now and Darth Vader demonstrated it clearly when he said "Millennium Falcon". Has anyone else noticed this? Can anyone provide an accurate IPA transcription for the word? It'd be amazing if English has a speech sound nobody has realised before.