ON0KUL/B Microwave Beacons JO20KV

Band Licensed Actual Power Status Heard
13cm 2320,975 2320,952 15W ERP OK PA0EZ 9/2006
6 cm 5670,975 NA 50W ERP  6/2006 NA
3cm 10368,975 10368,972 20W ERP OK PA0EZ 9/2006
1,2cm 24048,050 NA 20W ERP  1/2007 NA

The beacons are in the "smallest" tower of ON4AMX - we appreciate his assistance. We also thank the UBA for sponsoring our beaon license.


Simple and straightforward application of the DB6NT beacon transmitter, with a 60 degrees Xtal heater. Pout 1,2W and 10 dBi antenna (slotted waveguide). The beacon and the return loss (-38 dB at 2320 are shown) are shown below. I calculated the beacon antenna in stock alu tubing and frank PA4FP machined it. It works very well as far as I can tell, with little tuning. More antennas are available. QRG 2320,975 MHz, QRA JO20kv, 110 mASL.

beacon picbeacon return loss

3cm - Below in italics  the explanation of the original beacon. My comments in red. Nothing has changed except reprogramming the Atmel for the current callsign ON0KUL (by ON4CDQ - thanks) and locator. 10368,965 MHz, JO20kv, 110 mASL, ERP +/-10W.

ON4KUL 3/2000

The crew of ON4CP
In the 'proceedings' of the Microwave Roundtable 1999, Danny Orban, ON4AOD, gave a complete description of the 10 GHz beacon of Leuven.
Right after the October SHF contest, the beacon was modified. First, the instability of the frequency reference was solved. Secondly, a new PA was added: we now have more back off in the amplifier chain; the steps of the output power are closer to 6 dB.

The Beacon
OLD Call sign: ON4KUL
Frequency: 10.368,975 (currently ,965) GHz
OLD Locator: JO20IV
Antenna: Slotted waveguide, at 110 meters ASL (the antenna is on top of a 30-meter high building)
Identification: Call sign and locator (jo20iv).
Transmit power: Call sign and locator are transmitted at a nominal power of 31,6 dBm. The output power is then decreased to 26 / 21,2 / 15,9 / 9,3 and 2,1 dBm with 2 sec intervals.
The antenna is a slotted waveguide with 12 slot pairs. The measured radiation pattern is presented below. Maximum antenna gain is about 13 dBi. The minimum gain (in the dips) is about with 10 dB less; the gain in the "sidelobes" is about 5 dB less compared to the main direction.
If you hear the beacon, a report would be appreciated. Please email it to: beacon10ghz@on4cp.org.
It is our plan to experiment with PSK31 modulation on the beacon. The idea behind it is that we would like to investigate the feasibility of, and possible problems with PSK31 modulation at 10 GHz. Please keep an eye on www.on4cp.org for details.

beacon picbeacon pic