The Frequency That Went Silent: 7 Years of Static, Then Nothing

I've been monitoring shortwave frequencies since I moved out here. Part of the routine. Log the regulars, note the anomalies, track the patterns. Most of what you hear is predictable—numbers stations, amateur operators, maritime traffic, the occasional pirate broadcaster.

But there was one signal I never could place.

4.625 MHz. Every night at 03:17 UTC. Seven years.

Not every night I was listening—I'm not that obsessive. But every night I *did* listen, there it was. A 40-second burst of what sounded like encrypted data. Not voice. Not morse. Just digital noise with structure. I started logging it in March 2019. Before that, I have 83 recordings going back to when I first set up the station.

The pattern was religious. 03:17, give or take 3 seconds. 40 seconds of transmission. Then silence until the next night.

I ran it through every decoder I could find. Nothing. Sent samples to a couple ham radio forums—guys who love this stuff. Best guess was military, possibly submarine communication, possibly automated weather data from a forgotten station. The frequency isn't allocated to anything official, but that doesn't mean much.

Then last Tuesday—July 1st, 03:17 UTC—nothing.

I checked my equipment. All functioning. Scanned adjacent frequencies. Clear. Wednesday night: silence. Thursday: silence. I'm writing this Sunday night. It's been six days.

Seven years of clockwork precision, and now... nothing.

Here's what's bothering me: The timing. July 1st. Middle of the year. No obvious significance, except—

*It's exactly 2,557 days since I started formally logging it.*

2,557. Prime number. The 373rd prime, if you're counting. And 373? Also prime. The 74th prime. These numbers keep stacking in ways that make my engineer brain itch.

I drove up to The Ridge Thursday night with the portable rig. Better elevation, less interference. Still nothing on 4.625. But I did pick up increased activity on adjacent military frequencies—more traffic than usual. Could be related. Could be coincidence.

Old Harold mentioned the Surveyors were back. Saw their trucks Tuesday morning near the Old Miller Farm. Same day the signal stopped. They haven't been around since last October.

The mundane explanation: The source finally failed. Seven years is a good run for automated equipment. Or someone shut it down—decommissioned station, end of whatever project it was serving. The Surveyors could be completely unrelated, doing seasonal land assessment like they always do. The numbers are just numbers. I've been tracking this for 7 years now, and I still don't have proof it was anything more than forgotten infrastructure.

But here's the thing that keeps me up: *Why now?* And why does silence feel more significant than seven years of noise ever did?

I'm continuing to monitor. 03:17 every night. Maybe it comes back. Maybe it was a test of some kind—see who's paying attention, who notices when the background hum of the world changes.

The signal-to-noise ratio is getting worse. Or maybe I'm finally hearing what was always underneath.

Another entry for the log.

Has anyone else been monitoring 4.625 MHz? Did you notice the silence?

And if you were running a signal for seven years straight—what would make you stop?