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 around the Langrangian L2 point of the Earth-Moon-system. So it won´t be covered by the Moon, seen from Earth.
The signal of the S-band beacon is audible at about 2275.225 MHz. The used equipment is HDSDR software with an RTL-SDR-Stick with a 13 cm ATV Converter (LO=916 MHz), 13 cm LNA (Kuhne) at a 23/13cm and a dualband ringfeed in a 3 m dish.
Queqiao also carries a radio astronomy experiment for low frequency exploration in collaboration with dutch ASTRON. During the fly-by at the Moon 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.
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:
The french beacon F5ZBM is on air again. I found it accidentally, when looking for other french beacons. It is at a new location in JN18MN near Paris transmitting on 1,296.8475 MHz. Nice to monitor it in Mainz via aircraft scatter over a distance of 406 km!
The keying is in F1 with a very narrow spacing. Power is 10 W ERP into a slot antenna, as can be seeen at BEACONSPOT.eu
With the dish bearing eastwards tonight I mentioned the trace of a signal appearing and disappearing close to the local beacon of DF5AY. A quick look at beaconspot.eu told me, DB0TUD should be around there.
I copied DB0TUD in summer 2017 via rain scatter on 13 cm, but never on 23 cm so far.
Curious about the source of the signal after catching a “…UA…” I turned the dish to Dresden and monitored the frequency for about an hour. The mostly short appearences of the signal correlated with planes crossing the path to DB0TUD in JO61UA. After an hour or more I got a reflection containing some CW : ” …0TUD JO61…”.
Tonight I monitored OZ7IGY on 2,320.930 MHz via aircraft scatter. It was nice to see other beacons appearing shortly in the waterfall diagram.
OZ7IGY and friends in time lapse
From left to right:
2.320.900: DB0UX, JN48FX, 105 km, tropo
2,320.910: DB0XY, JN51EU, 263 km, aircraft scatter
2.320.920: DB0VC, JN54IF, 509 km, aircraft scatter
2,320.930: OZ7IGY, JN55WM, 670 km, aircraft scatter
The dish was bearing 20° to OZ7IGY. The -3 dB beamwidth is just 3.2° on 13 cm.
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.
After installation of new transverters for 23 and 13 cm with stabilized LOs a couple of months ago. I gathered some experience in using JT65C mode on EME. So I undertook a new attempt to receive and decode G8MBU via aircraft scatter today. As antenna I use a 3 m dish with a dual band ringfeed.
Path DJ5AR to G8MBU
The beacon is located at Cowes on the Isle of Wight, IO91IR37, 683 km from Mainz, JN49CV. It runs 2 W power into an omnidirectional dual alford slot antenna. The mode used is JT65c. Nominal frequency is 1296.800 MHz. To successfully decode the signal, the SSB dial should be set to 1296.7986 MHz, to get a tuning tone of 1400 Hz in WSJT.
There is a small window between the Isle of Wight and Mainz, where high flying aircraft can be “seen” from either places. But only a few airplanes cross the path within and fewer fly along the path. Reflections of G8MBU could be seen from time to time, but mostly too weak and too short to provide decodes. It took nearly 3 hours until the first decode happened at -22 dB and just some minutes later a second one appeared on the display at -21 dB:
The other day I had a look on Dominiques QRZ.COM page and saw, he claimed to have a beacon on 13 cm as well. The frequency seemed to be quite strange: 2308.037 MHz
It´s because the situation in Switzerland is different, than in other european countries:
2300 – 2308 MHz with special permission only
2308 – 2312 MHz License classes 1, 2 and CEPT
2312 – 2400 MHz with special permission only
My new Kuhne MKU 23 G4 transverter covers certain segements of the band. so I switched to 2304 – 2306 MHz and tried to listen on an IF around 148.037 MHz and was disappointed: nil. I expected a strong signal as the same beacon on 1296.050 MHz ist up to 40 dB above noise under normal conditions.
A weak trace can be seen at the IF of 1392.032 MHz (LO 916 MHz)
I contacted Dominique and he assured, the beacon should be on air. So I tried with the setup, I received ISEE-3 quite a time ago and monitored the path for airplanes. So after a short while, there was a trace to be seen on 2308.032 MHz. Even the keyed carrier could be heard deep in the noise, when larger aircrafts crossed or flew along the path.
Characteristic “hook” at the begin of the carrier after keying the call
So I proudly added beacon #23 to my 13 cm list.
HB9BBD/B: 2308.032 MHz, JN47GA, 1662 m. asl, PWR 8W, ERP 100W beaming north
March 23rd, 2017, Update
I had a second try with the MKU 23 G4 this morning and was able to receive the beacon with this gear as well on 2308.032 MHz.