A faint L-band signal, logged from Eureka, California.
We found it by accident, scanning the L band with RTL-SDR dongles from Eureka, California. It sits far below the noise. It matches no known transmitter on Earth or in orbit.
Its frequency won't hold still. It sinks low and slow, then climbs high and fast, and everything inside it stretches by the same ratio. It isn't Doppler and it isn't drift. Lock onto the pulse that strikes every hour, re-time everything else to it, and it decodes.
Thirteen stations on one clock. It calls itself Epoch Modulation.
The antenna is on a rooftop in Old Town, within sight of the bay. Marine Layer keeps it.
Someone filed an FCC complaint to find the source. After months of coaxing, engineers came out with field strength meters, found it within Part 15 limits, and said it was out of their hands.
An installation. All stations, voices and songs are fictional.