This signal continuously broadcasts in short blips. Broadcast periodically switches between the two VHFVery High Frequency (30-300 MHz) frequencies. The UHFUltra High Frequency (300-3000 MHz) broadcast is sent with a much shorter delay between pulses and also more irregularly.
"Unknown-1536125", heard all the time on 462.407 MHzMegaHertz (MHz) 10^6 Hz and 173.226 MHzMegaHertz (MHz) 10^6 Hz, Massachusetts, USA area. December 2014. --Cartoonman (talk) 09:24, 30 December 2015 (NZDT)
Avsa242 posted: OP here. I don't know why I hadn't thought of this before, but I did a little Googling and found that the two VHFVery High Frequency (30-300 MHz) freq's are registered to an address of a town water supply. Street view shows two water tanks/towers at that address, so I'm guessing this is some sort of monitoring system. Saw your video- the waterfall looks similar, at least, to the one I posted, but it didn't sound to me like the same signal. --Cartoonman (talk) 09:24, 30 December 2015 (NZDT)
151.7815 MHzMegaHertz (MHz) 10^6 Hz, 153.6125 MHzMegaHertz (MHz) 10^6 Hz, 469.7605 MHzMegaHertz (MHz) 10^6 Hz