Tag Archives: DB0UX

F5ZNI: Beacon #34 on 13 cm

December 29th, 2019

By performing my daily beacon check, I noticed a weak keyed carrier in between the spacing of the F1 signal of DB0UX on 2320.900 MHz. I assumed to see F6DWG/B, which I monitored around the .900 before. But it didn´t take long to find out, that the real signal (mark) was the lower carrier and after a while I learned, it was F5ZNI using reverse F1 keying. Later in the evening the signal increased due to good tropo conditions, as can be seen in the pictures. F5ZNI is the 34th beacon I received in the 13 cm (S) Band

F5ZNI and DB0UX in PowerSDR

I am always happy about new beacons, but this case is an example, why beacon coordination and using standards is most important. First of all, reverse F1 keying is always bad, as you are used to listen to the upper carrier of the signal. In case there is an unkeyed carrier in between the text, you can easily identify the mark, where to listen. But if there is text keyed nearly all the time, as F5ZNI does, it is rather time consuming until the mark is identified.

The DB0UX signal was strong and the frequency is locked to a reference, while F5ZNI is drifting a little. So it was obvious, that there was a second signal in place. If the french beacon would have been locked to 2320.900 MHz too and would use the standard A1 or F1 keying, there would have been no chance for me to monitor or even to take notice of it.

An excerpt from BEACONSPOT.UK shows the situation on 2320.900 MHz:

BeaconNominal FrequencyLocatorLast SpottedLast FrequencyStatus
F6DWG2320.900JN19BQ2019-05-312320.898Dead/lost
HG3BUC2320.900JN96CC2019-10-112320.897Operational
OZ5SHF2320.900JO45VX2019-08-242320.900Operational on spot date
DB0MJ2320.900JO31UB2019-12-292320.905Operational
ON0TB2320.900JO30BM2019-09-202320.897Dead/lost
DB0UX2320.900JN48FX2019-12-292320.900Operational on spot date
F1ZCC2320.900JN08XSUncertain - new spot required
SR1SHS2320.900JO73PG2019-12-302320.900Operational
IQ5FI2320.903JN53SR2019-12-282320.901Operational
F5ZNI2320.904JN19BQ2019-12-302320.899Operational on spot date


Depending on the location and the conditions, there will be more or less interference on 230.900 MHz

So I am urging all beacon keepers to make use of the service provided by the
IARU R1 VHF/UHF/MW Beacon Coordinator. When designing a beacon, please respect chapter 11 “Beacon Requirements” in the IARU-R1 VHF Handbook.

Windmill Scatter

August 30th, 2017

As the weather forecast promised heavy thunderstorms for today, I was looking out for scatter points on 13 cm. Pointing to eastern France, I found a heavily scattered signal of DB0UX in JN48FX in 204°.

But the sound was quite strange and rhythmic. When taking a look out of the window, I saw the dish pointing at two windmills in 1 km distance.

This kind of scatter is not very helpful, but a nice experience anyway.