VA2IW/B 10 GHz CW and Q65 Transmit Beacon
By: Bertrand Zauhar, VE2ZAZ - VA2IW
Last updated: 2026/10/01. The latest changes are shown in red font


Frequency:
Modulation:
Messages:
Output Power:
Antenna:
Location:
Elevation:
Controller:
 		10,368.420 MHz, frequency is GPS-referenced.
CW, Q65 (60 seconds, Submode D), Keydown period.
 CW: "VA2IW/B", Q65: "VA2IW/B FN25".
Approximately 500 mW at the antenna.
16-slot waveguide antenna. mostly-omnidirectional, horizontal polarization.
FN25bk (Gatineau, Québec, Canada). 45° 26' 22'' N  75° 52' 29'' W
13m (42 ft) AGL, 146m (480 ft) ASL.
STM32 BlackPill, custom F/W and H/W designs.

The VA2IW/B Time Frame Formats




Decoding the Q65-60D frame

To pick up the Q65-60D frame, use the WSJT-X software, setting it to decode Q65, T/R 60 seconds, Submode D. Set the receiver to SSB mode, tune the receiver to 1 KHz lower than the carrier, 10368.419 MHz. This will produce a tone spread between 1000 Hz and 1867 Hz, as seen below.

Operational Notes
  • This 10 GHz beacon may be shut off during microwave contests and activity periods in which the author participates.
  • The beacon is mounted above the antenna rotator on the author's tower. Since the antenna radiation pattern is not truly omni-directional, signal strength variations of a few dB are to be expected, even for local stations, as the author rotates his antenna stack.
Technical Details
A youTube video describing the beacon in more details is available here:
  • The beacon carrier frequency is referenced to a 10MHz GPS-disciplined Oscillator. The resulting carrier frequency accuracy should be of better than +/- 1 Hz at the target frequency.
  • The Q65 frequency shift keying is produced by slightly moving the 10 MHz OCXO frequency via the control Digital-to-Analog-Converter (DAC).
  • The firmware supports the following Q65 transmission modes: 15A, 15B, 15C, 30A, 30B, 30C, 30D, 60A, 60B, 60C, 60D and "60E. The NTMS-preferred mode is 60 seconds Submode D. Other modes may be activated on demand.
BEACON RF BLOCK DIAGRAM


BEACON CONTROL BLOCK DIAGRAM


Signal Reports

 Do not under-estimate microwave weak signal performance! As a proof, just a few days after putting the beacon in service, I had already received several reception reports from hams. And the best report so far has been from VE3KH in FN03cg, decoding many Q65 frames from a distance of 393 km:
 

Moreover, K2UA in FN12fr, from a distance of 325 km, reported a full copy of the CW message. He provided this screen capture showing the signal strength:


Reception reports are welcome via email. Contact here.