Category Archives: Propagation

Moon Bounce out of the Boot

September 28th, 2019

On the annual service day of the DARC districts Saarland and Rhineland-Palatinate I had the pleasure to hold a lecture about EME basics and how to get into. Afterwards I invited the audience to try a live moon bounce QSO on 432 MHz from the parking lot outside. I had prepared some standard equipment of the kind, many might have in their shacks:

  • Transceiver Yaesu FT-897
  • 15-Element Yagi (YU7EF )
  • PA Gemini 70, ca. 200 W
  • LNA SHF-Elektronik, 0,8 dB NF
EME rig in the boot, Photo by courtesy of Klaus, DF6WN

Unfortunately it was rainy outside, the moon close to the sun and a G2 solar storm in progress. When swithing on the transceiver, I noticed some quite massive local QRM. Nevertheless I contacted Bernd, DL7APV, who had agreed in a sked, by phone, to tell him about the noise and that we were ready to go.

Bernd´s array of 128 x 11 elemnt yagis during a barbeque last June

As the noise level went up and down and Bernd is one of the big guns on 70 cm, we were able to decode most of his transmissions despite all adversities. Finally we completed the QSO. That was a great job, Bernd!

I enjoyed to be in Saarbrücken and would like to say thank you to Eugen, DK8VR and his team for organising DST 2019!

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.

 

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.

 

F5ZBM on Air again!

April 20th, 2018

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

Another view on F5ZBM in WSJT-X Wide Graph

 

DB0TUD as Beacon #60 on 23 cm

March, 23rd, 2018

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…”.

OZ7IGY and friends

December 22nd, 2017

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.

 

A digital evening on 23 cm

October 25th, 2017

There was nice activity in JT9F on 23 cm tonight. It seems this mode works fine with aircraft scatter. I first worked Conrad, PA5Y in JO21VO (255 km) and Sam, G4DDK in JO02VO (540 km) via Tropo. Then logged a QSO with Neil, G4BRK in IO91HP using mainly aircraft scatter. In another test I decoded Neil, G4DBN in IO93NR (756 km) by reflections on airplanes. PA0JME and ON5KTO were calling CQ, but not replying to my calls. Instead I worked John, G4BAO in JO02cg (619 km) in an (too) easy way.

Worked stations in green, the heard ones in blue.

Anyway, it was a promising and exiting evening!

Addendum October 27th, 2017

Yesterday I logged Rien, PA0JME, Wim, ON5KTO and John, G4ZTR, also in JT9F on 23 cm.

Chatting with John, G4BAO, last night, I learned, he recently initiated a “Digifest” on the microwave bands every Wednesday. This resulted in what happened two days ago. In my opinion it´s a very good idea to have such an activity evening beside the regular contests.