ChannelSPURIOUS EMISSIONS
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Episode 13 · Numbers Stations · Series 01: The Listening Station

Who broadcasts numbers on shortwave, and what reaches my station?

A frame from the draft of episode 13, Numbers StationsComing soon
Release
Coming soon
Length
10:52
On the dial
Shortwave, by timetable
Signal
Numbers stations

What it covers

Numbers stations are shortwave broadcasts from intelligence agencies to their agents abroad: secret codes for spies, really. In this video: why an agency would broadcast a secret, how a one-time pad makes the numbers say nothing, what still leaks from a timetable, the 2011 arrest of a couple at their shortwave receiver, and how my own station in the Puget Sound records every transmission on the published schedule.

The written guide: set this up yourself

Chapters

  1. 0:00Intro
  2. 0:41A secret code for spies
  3. 1:24Why broadcast a secret
  4. 2:34Numbers that say nothing
  5. 3:19What still leaks
  6. 4:49Tuesdays and Thursdays
  7. 5:56Who is on the air
  8. 7:30A timetable for my receiver
  9. 8:34What reaches the Puget Sound
  10. 9:34Intro

Frames from the draft

Numbers Stations: Intro
01 Intro
Numbers Stations: A secret code for spies
02 A secret code for spies
Numbers Stations: Why broadcast a secret
03 Why broadcast a secret
Numbers Stations: Numbers that say nothing
04 Numbers that say nothing
Numbers Stations: What still leaks
05 What still leaks
Numbers Stations: Tuesdays and Thursdays
06 Tuesdays and Thursdays
Numbers Stations: Who is on the air
07 Who is on the air
Numbers Stations: A timetable for my receiver
08 A timetable for my receiver
Numbers Stations: What reaches the Puget Sound
09 What reaches the Puget Sound
Numbers Stations: Intro
10 Intro

Gear in this episode

XHDATA D-808a portable shortwave radio with SSB (and the air band)
Tecsun PL-368a pocket shortwave radio with SSB
Eton Elite 750a classic big portable with SSB and a rotating AM antenna
Tecsun PL-880a portable shortwave radio with SSB
DX-286a great portable receiver (TEF6686 chip), but no SSB, so it can't play single-sideband stations like V32
RX-888 Mk IIthe receiver that hears all of shortwave at once (mine is from OpenSourceSDRLab)
MLA-30+ loop antennathe small active loop antenna for shortwave
HP EliteDesk small form factor PCthe shortwave computer I call Raphael (mine was rescued from e-waste)
CyberPower CP1500PFCLCD UPS (1500 VA, sine wave)the battery backup that keeps almost all of my station running through a power cut

Software and references

Priyom.orgpriyom.orgthe volunteer catalogue of numbers stations and military signals, and the public schedule my station reads
Priyom schedulepriyom.orgthe published timetable: when and where each station should appear
WebSDR.orgwebsdr.orgshortwave receivers around the world that anyone can tune from a web browser
KiwiSDR maprx.linkfanel.neta map of many more public web receivers around the world
One-time paden.wikipedia.orghow the cipher works, and why it cannot be broken when it is used correctly
ka9q-radiogithub.comthe open-source program that splits the receiver's stream into one channel per transmission and draws the spectrum (by Phil Karn; episode 5)

What is simplified, and what is invented

  • I own and recommend all five portable radios at the top of the gear list. All but the DX-286 have SSB (single sideband), which many numbers stations, Morse code and the ham bands need.
  • The recorder, the letter-beacon receiver and the waterfall archive are small programs I wrote for my station. They are not public.
  • The opening voice is G06, "German Lady", a Russian station rarely heard now. Recording: Sektor sieben Blau, 5442 kHz, 13 April 2018, CC0 (Wikimedia Commons): https://commons.wikimedia.org/wiki/File:Zahlensendernumber-station-g06-german-lady-long-message-13042018-5442-khz-1930-utc.mp3
  • V32 recording: Wikimedia Commons user آه, 7842 kHz, 11 March 2026, CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). I used 8 seconds, set its level and faded its ends: https://commons.wikimedia.org/wiki/File:V32_Farsi_numbers_station_recording,_7842_kHz,_March_2026.ogg
  • The Buzzer recording (and its message, MDZhB MDZhB 26 47 GERUNOK): Cqeme, 4625 kHz, 24 January 2013, CC0 (Wikimedia Commons): https://commons.wikimedia.org/wiki/File:Buzzer_2013_01_24.ogg
  • XPA2 and the K beacon are real recordings from my own station: XPA2 on 12218 kHz, K on 7039.3 kHz.
  • Station facts are from Priyom.org's catalogue (CC BY-NC-SA 4.0). The link between the 2011 arrest and the Tuesday and Thursday schedule is Priyom's hypothesis.
  • V32 today: 7910 kHz, upper sideband, every day at 02:00 and 18:00 UTC (on the US West Coast in winter: 6 PM the day before, and 10 AM). Source: Priyom's schedule.
  • The pictures of the 2011 raid and arrest are illustrations: the people in them are invented, not the real couple. The kid with the radio, the man in the square and the oak are a sketch of an idea, too.
  • All counts are from my own station's first nights, rounded where noted. My antenna is still a small loop.