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IARUMS R1 Technical Resources

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How to start an Intruder Watch

As the amount of all kind of intruders in the HAM Radio bands is rapidly crowing, the role of the IARU Monitoring System (IARUMS) is becoming more and more important. A number of national Monitoring Coordinators and Volunteers is watching our bands since many years, but more needs to be done to raise awareness of societies and countries where there exists actually no national monitoring team.

Your help, as Radio-Amateur operator or SWL is key to contribute in keeping our most important asset – the HAM Radio spectrum – free of intruders.

How can you help? (read more…)

Monitoring with WebSDR

A WebSDR is a simple Software-Defined Radio receiver connected to the internet, allowing multiple users to listen and tune it simultaneously. SDR technology makes possible that all users can tune independently, and so listen to different signals. WebSDR

Monitoring with KiwiSDR Network

KiwiSDR Network, a KiwiSDR receiver network available on the internet with Direction Finding feature TDoA: Time Differerence of Arrival.

TDoA feature Direction Finding example

ITU and CEPT Regulations and Documents

Signal Identification

F1B signal on 20 meters. BW = 500 Hz


OTH Radar antenna
Four OTH Radar Contayner simultaneous transmissions on 40 m.

Fishing Buoys on 10 m

Devices installed in fishing buoys used to help the radiolocation of fishing gear – nets, longlines – send illegal transmissions in A1A (CW) and F1B (FSK) on the 10 m band, mostly from 28000 kHz to 28450 kHz. These transmissions are repeatedly sent every few minutes all day long.
Due to propagation conditions and sporadic E‑layers, they are usually best received during the summer months.
The largest amount of the fishing buoys transmit A1A (CW) signals consisting in a short preamble tone (few seconds long) followed by one to 3 letters. Characteristic feature is also the mostly slowly rising preamble tone before the identifier follows. However, buoys with a constant carrier are also observed.
Fishing buoys using F1B signals transmit their GPS position in an encrypted message. Shift is ca. 300 Hz.

List of Fishing buoys (August 2019)

IARUMS R1 Fishing buoys Report 2021

Driftnet buoys
Driftnet buoy sonogram
Driftnet buoy transmission
Print This Page Updated on January 17, 2023

Materials on this website may be subject to copyright.