Shanji

Pretty sure it's not, this is a common artifact from having the beginning and the end of the sound loop being at a different sound amplitude from each other, resulting in the audible pop when the next loop starts, the mod I linked addresses that by smoothing out those amplitude discrepancies. You can hear how it should actually sound like in this video

This seems to be an issue since release and somehow hasn't been brought up yet in the forums. Video example of the sound: Notice the loud popping noise inbetween the tone loop, I've seen other people complain about this and there's even a mod that addresses the issue: Harrier Sidearm & RWR tone fix (digitalcombatsimulator.com) Edit: seems like the same problem happens to the RWR tone as well.

Loving the mod, it works great, cant wait to see more features added to it, stuff like the RWR warning making the LEDs flash would be simply amazing! You should definitely upload this to the user files website.