Short Rules for FMT Participation
These are simplified, beginner-friendly rules explaining how FMT tours work. No formulas, no advanced theory — only the essentials.
Who can participate?
- Any radio amateur with basic HF or SDR equipment
- You don’t need a frequency standard or special lab gear
- Both beginners and experts compete in separate classes
What is the goal?
The goal is to measure the frequency and timing of the FMT beacon signal as accurately as your equipment allows. Your result is compared to the reference, and you receive a score.
Note / Limitation:
- HF skywave propagation can shift the received carrier frequency (Doppler and frequency shift).
- Calibrations and reference equipment help reduce systematic offsets, but they do not make the HF channel laboratory-grade.
- Scoring is comparative; the aim is to compare measurements against the reference, not to establish the transmitter's absolute "true" frequency.
How tours work
- Each tour has a published UTC time window
- Tune to the announced FMT frequency
- Record the signal or observe it in real time
- After the end of the tour, analyze your recording
- Submit measured values on the website
What you need to submit
- Your measured carrier frequency (FREQ)
- Pulse duration (PULSE): measure the duration of the 3rd pulse in a packet of three 1 kHz sinusoidal pulses (1st = 100 ms, pause 100 ms; 2nd = 50 ms, pause 100 ms; 3rd varies during competition)
- 1 PPS offset (PPS): the time offset of the start of this pulse packet relative to the GPS 1 PPS reference
- Optional notes about your equipment
Note: Submissions can be corrected before the tour closes.
Classes (PRO and Hobby)
Hobby class
Regular HF or SDR setups. Beginners start here.
PRO class
GPSDO-based or laboratory-grade setups aiming at very high precision.
Scoring (simple explanation)
Your score is based on how close your measurements are to the reference values. Smaller errors give more points. Detailed mathematical scoring is described in the full Rules page.