Category Archives: Beacons

Strange Conditions Today

January 1st, 2020

I got up quite early today and decided to check the beacons on 23 cm. When beaming to LA1UHG, there was a noticeable signal in F1 about 1 kHz above its frequency. It was easy to read it as DB0LB from the back of the dish. But it seemed, there was another faint signal right beside the spacing carrier. With the help of my SDR radio I could set very narrow filters and after a while of listening, I identified it as LA1UHG, JO59FB, 1028 km. Wow!

But the signal faded out more and more and at least it disappeared.

LA1UHG just 140 Hz below the space carrier of DB0LB

Later this morning, the dish still pointing north, I heard Kurt, OE5XBL, chatting in SSB with Rudi, OE5VRL/5, both with very strong signals on 23 cm. Expecting a huge signal, I turned the antenna to Kurt, but there was no significant increase in signal strength. I called in and the three of us were talking about the conditions and to meet for a beer at the GHz convention in Dorsten next February, when Kurt was called by Dave, G4RQI. I had tried with him earlier without any success, and so, to be honest, I was a little annoyed by this. Even, when turning the dish to the UK, I couldn´t copy anything of Dave’s transmissions, while he was working Kurt and Rudi. These were enough indications, that the inversion was at a too high altitude for me, to enter it. So I went for a long walk with my XYL in the nearby vineyards.

The inversion is at an altitude of about 1000 m (Courtesy DWD)

In the evening I performed another beacon check. It was funny to see beacons, the dish was pointing to, as well as others from the back of the dish

Dish pointing southeast: DB0UX, DB0VC, DB0AAT (from left to right)

Turning the dish, confirmed the experience I had in the the morning: Pointing southeast I saw DB0VC, JO54IF, next to DB0AAT, JN67HU. Turning the dish towards Kiel in the north, the signal of DB0VC increased just a little. Maybe, it has been reflected by a mountain range about 50 km southeast of me.

Dish pointing north: DB0UX, DB0XY, DB0VC, OZ7IGY (from left to right)

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.

DB0XY back on Air

December 17th, 2019

As the beacon keeper Thomas, DL4EAU, wrote me, the DB0XY beacons in JO51EU are back on air. The frequencies are 1296.912, 2320.912 and 10368.912 MHz. All are locked to a GPS reference now.

DB0XY on 1296.912 MHz in JN49CV: A weak tropo trace, but many nice reflections on airplanes
DB0XY on 2320.912 MHz: No trace via tropo, but many reflections on planes

F1ZBK in JN38BP back on air on 1296.854 MHz

June 7th, 2019
Doppler shifted traces (1000 Hz = 1296.854 MHz)

When looking for EA2TZ/B during a beacon check a couple of days ago, I mentioned a signal with strong doppler shift about a khz below. As I like the challenge to identify new beacons, I started monitoring it. It became a kind of a nightmare, trying to to catch the beacons callsign. It seems to be very chatty, transmitting a whole bunch of unuseful text. despite the fact I got a lot of good quality fragments via aircraft scatter, it took me hours to identify it as F1ZBK. At least I am pretty sure it is, as there is a second callsign in the end of the text: F1DND, maybe it´s the keepers call.

The text decoded so far is:
—— beacon f1zbk jn38bp nancy … 854 khz … 5 watt … f1dnd … orange KA … ——-
Where the “…” represent gaps and KA is the prosign for “Attention” or “New Message” (not to be used at the end of a message, like AR).

There are many beacons running in bad modes like reversed F2A or keying the subcarrier of F2A, but transmitting such a lot of stuff is worse.

It would be a great advantage, if all beacon keepers will respect the beacon requirements as published in the VHF Handbook of IARU R1.

OK0ER via Aircraft Scatter on 13 cm

October 22nd, 2018

As OK0EA was audible this morning on 23 and 13 cm I had a look for other, more distant beacons in OK. After noticing a very short and weak signal on 2320.9085 MHz, I monitored the frequency over a couple of hours and saw many doppler shifted traces, typical for aircraft scatter. Very soon I copied “…9DP…”, when a B777 crossed the path and was sure to see OK0ER in JN99DP in the waterfall diagram. At least 4 Airbuses A380 crossed the path one after the other, giving nice reflections.

OK0ER transmits 1.5 W into a slot antenna in 675 m asl. The distance is 722 km.

 

Longjiang-2 S-Band Beacon received over 400000 km

January 10th, 2019

As I digged a little deeper, I learned, the source of the signal on 2275,225 is not Queqiao, but it is it´s companion Longjiang-2 or DSLWP-B in an orbit around the moon.

August 23rd, 2018

Designed as a relay for the planned chinese Chang’e 4 misson to explore the far side of the Moon with a lander and a rover, the Queqiao probe has reached it´s final destination 60000 km behind the Moon. There it is in a halo orbit with a radius of 15000 km around  the Langrangian L2 point of the Earth-Moon-system. So it won´t be covered by the Moon, seen from Earth.

Queqiao also carries a radio astronomy experiment for low frequency exploration in collaboration with dutch ASTRON. After the lainch in May 2018 two microsatellites Longjiang-1 (DSLWP-A) and Longjiang-2 (DSLWP-B) were released, to enter orbits around the moon. These satellites carry a radio astronomy experiment as well as amateur radio payloads. While Longjiang-1 went lost, Longjiang-2 is operating and can be monitored in the 70 cm band as well as in the S-Band.

The signal of the S-band beacon is audible at about 2275.225 MHz. The used equipment is HDSDR software with a RTL-SDR-Stick connected to a 13 cm ATV Converter (LO=916 MHz) and a 13 cm LNA (Kuhne) at a 23/13cm dualband ringfeed in my 3 m dish.

New Beacon SR1KOL in JO74SE

July 30th, 2018

After I noticed some spots for SR1KOL in JO74SE on 1296.960 MHz, I monitored the frequency using WSJT-X Wide Graph. About 400 Hz below the nominal frequency traces of a F1 signal can be seen, when airplanes cross the path to the beacon. The signal is not audible, but I am pretty sure, it is SR1KOL.

Traces of SR1KOL in JO74SE, “1000” = 1296.960 MHz. The strong signal at the very left is a birdie.

Some information can be found on the website of Polski Klub UKF: It is located on a high rise building in Kołobrzeg, 40 m above ground. The power is 3 W into a slot antenna. Beacon keeper is Andrzej, SQ1GU.

The video shows an A380 crossing the path between DJ5AR and SR1KOL. At minute 2:00 the plane crosses the first time and at minute 4:00 after a turn it crosses a second time. Mind the traces at 580 Hz in the waterfall diagram. The 1000 Hz mark corresponds to 1296.960 MHz.

Irek, SP5MX, who was involved in building the beacon and who repaired it recently, told me, the beacons reference is an OCXO withtout any GPS-lock. So possibly the beacon may transmit 400 Hz lower than defined.

At least in the morning of July 31st audible reflections could be heard via an Airbus A330. This time the 1000 Hz mark correspondents to 1296.9596 MHz.

After 10 seconds the noise becomes a kind of ‘musical’. Another 10 seconds later experienced ears can hear the tone.

 

New Beacon DB0MFI on 23 and 13 cm

June 18th, 2018

This morning I had a look for DB0MFI, a new beacon on 1296.940 MHz in JN58HW. It is audible with 529 constantly via tropo and peaking 579 via aircraft scatter. The power is 5 W into a 4 times stacked big wheel antenna.

 

In the afternoon I went for it on 2320.940 MHz. Faint reflections on some airplanes were audible and traces could be seen in the waterfall of WSJT-X Wide Graph: