FMT Test Transmission Format
This document defines the deterministic transmission format used for FMT test runs.
Transmission format
Jan 4, 2026
Transmission timeline for participants
All times below are offsets from transmission start. If you catch any part of the signal, you can use these points to estimate what comes next.
Total on air
21 min 42 s
Calibration part
5 min 00 s
Test intro
2 min 52 s
Cycle spacing
138 s
On-air picture
What happens after start
Part 1
Calibration part
T+00:00 → T+05:00 · 5 min 00 s
Calibration QST repeats, then a 60-second reference carrier, then a short 5-second pause.
Part 2
Test intro
T+05:01 → T+07:52 · 2 min 52 s
Test QST block before the regular cycles begin.
Cycles 1-5
Regular cycle
Starts every 138 s · 2 min 18 s
Each cycle has the same order: short pause, 60-second pulse block, 60-second carrier, short CW ID.
Cycle 6
Final cycle
T+19:22 → T+21:42 · 2 min 20 s
The last cycle keeps the pulse and carrier blocks, then ends with final sign-off.
Main reference points
Inside one cycle
Cycles 1-5
Regular cycle
2 s pause + 60 s pulse + 60 s carrier + about 12 s CW ID
Cycle 6
Final cycle
2 s pause + 60 s pulse + 60 s carrier + 10 s final sign-off
Band Slot Preamble (Tour Calibration)
Before the FMT Test measurement part, the transmitter sends a short preamble that helps participants estimate their current receive-side frequency offset. See the timing overview above for the exact current sequence and durations.
- Short QST: see timing overview above
- Calibration carrier: 60 s unmodulated carrier (CW) on the published calibration carrier frequency
Purpose: Measure this 60 s calibration carrier to estimate the current RX offset (Doppler + receiver chain). Apply the correction to your carrier frequency measurement for this tour. Using the calibration carrier is optional but recommended for best accuracy.
Note: The calibration carrier is not a separate contest task and does not replace the carrier blocks inside the FMT Test measurement part. It is an additional reference sent immediately before that part of the transmission.
Transmission Flow
Slot level (tour transmission): follow the transmission timeline shown above: calibration part → test intro → measurement cycles
FMT Test measurement part: test intro → cycle 1 → cycle 2 → cycle 3 → cycle 4 → cycle 5 → final cycle / sign-off. See the timing overview above for the exact offsets and durations.
- Initial QST / test intro: see timing overview above
- Cycles 1-5: Pulse 60 s → Carrier 60 s → Short CW ID. Final cycle ends with sign-off. See timing overview above.
- Final cycle ends with:
FMT TEST DE SN0FMT SK
Overview
- FMT Test measurement part: duration and structure are defined by the timing overview above
- Calibration part before the test: see timing overview above
- Start aligned to a published UTC time
- Deterministic internal structure
- For pulse measurements, tune to the published USB pulse frequency (CW − 1 kHz). For carrier measurements, stay on the CW carrier frequency.
Initial QST
The FMT Test measurement part begins with a CW identification phase used for tuning and confirming reception. See the timing overview above for the current duration.
QST DE SN0FMT TEST FMT
Measurement Cycles
After the test intro, six measurement cycles are transmitted. Cycles 1-5 share the same structure, while the final cycle ends with sign-off. See the timing overview above for the current durations and spacing.
- Pulse signal (60 seconds)
- Unmodulated carrier (60 seconds)
- Short CW identification in cycles 1-5; final sign-off in cycle 6
FMT TEST DE SN0FMT
What Is Measured
Participants may use the 60 s calibration carrier transmitted immediately before the FMT Test measurement part to estimate current RX offset and improve accuracy. The contest result is still based on the carrier blocks inside the measurement cycles described above.