Yes, another topic on Whelens. This is a little glitch I have noticed on most, if not all Whelens with an ESC-864 analog controller. I have noticed that the pitch gets 10-20 hz higher or lower than it normally is. For example, Railman YT's video of Clark State Rd @ Headley Rd WPS-4004 with it's peak pitch at 745 hz. But when TommyBNSF recorded it, it has 10 hz higher at 755 hz. I have also noticed this with the Merlin Drive Dual Tone WPS-4004, which its controls were swapped with the Whetstone Park 4004. It seems that it will be at 755/880 hz most of the time, but when it was recorded for the 2019 Ohio State Tornado drill, it was at 735/860 hz. I'm assuming this might have something to do with the batteries? or if it is just an actual glitch in the motherboards. I have also noticed this with lower pitch analogs as well.
Clark State Rd @ Headley Rd
RailmanYT's video at 745 hz: https://www.youtube.com/watch?v=R2yDcU67g24&t=38s
TommyBNSF's video at 755 hz: https://www.youtube.com/watch?v=O8-e1NJrhQs
Merlin Drive Behind Kroger
Thunderbolt1000TFan's video at 755/880 hz: https://www.youtube.com/watch?v=Dl9BCDpfBZE&t=3s
Tommy's Aviation & Sirens' video at 735/860 hz: https://www.youtube.com/watch?v=UP7YZ_xRxu8&t=26s