Beacon check

March 13th, 2013

There are some beacons I am used to check whenever I am in my shack. One of them is quite a special one: DB0LTG on 1296,745 MHz.

This beacon provides a very stable signal of normally 40 dB, usable for antenna calibration, especially when the sun isn´t available at night time. On the other hand the beacon is part of a linear transponder located on the Unnenberg near Gummersbach, Germany. The input is in the 432 MHz band and the output in the 1296 MHz band. In my SDR I can even see the noise floor of the transponder next to the beacon.

DB0LTG

DB0LTG with noisefloor

When talking about the transponder, Rudi, OE5VRL/5 was the only one I worked on it until now. We had big fun in performing a QSO via DB0LTG in October 2012 when conditions allowed such a crazy test. While performing my daily beacon check tonight, I noticed some SSB signals on the transponder. So I prepared my (poor) 70 cm equipment and set it to the input frequency. My first call was heard and so I enjoyed chatting to the guys who were initially setting up and now using this nice toy every Wednesday night.

By the way: The distance from Mainz to Gummersbach is 135 km. For details of transponder and beacon visit the website of DB0LTG.

Digital World – Digital Moon

March 11th, 2013

Despite all the discussions about using digital modes in moonbounce I want to gather own experiences. After installing WSJT last Xmas I could decode a couple of stations on EME without any problems. First TX tests resulted in an intolerable frequency drift, which could be limited with the installation of a crystal heater. Then I started with real tests, but in all skeds no one could decode me! I had no clue what went wrong. So I changed – quick and dirty – the PC producing the audio stream. Now OK1CS, HB9Q and G4CCH could be worked in JT65C. Last sunday morning I saw a big signal in the waterfall diagram of my SDR. It was JA6AHB and it was a question of a few minutes to put him to the log. All stations worked so far, have been audible in my headphones.

I think, in general it is nice to use digital modes to work others via EME. But there is much more skill in involving the ears to have success in completing an QSO. It´s always great to HEAR the final rogers. Despite that I will not deny the use of digital modes. Why not working someone digital and then, maybe after some improvements, top it in working him in CW again? As long as all information like callsigns, reports and rogers, necessary for a complete QSO, have passed the radio channel, it will be a valid QSO. This is my position.

I will continue to explore digital modes:

NoDeepSearch

The TX signal will be processed on my FT-987 with a seperate PC. RX is done with my SDR and another PC. By not typing in the other callsign or using call3.txt on the RX side I am quite sure in ‘really’ receiving the callsigns.

Aircraft Scatter, AirScout and the ISS

February 23rd, 2013

Frank, DL2ALF has written an amazing tool for aircraft scatter prediction, called AirScout. Positions of planes are shown in a map like at http://planefinder.net or http://www.flightradar24.com, but in addition the path and the part of it, where planes could be seen from both stations will be marked. Frank is using open street map for the maps and an elevation model of NOAA to respect the topography of the path. I made use of a beta version last Tuesday in the NAC on 23 cm and found it extremly helpful.

The latest version can be found here.

Thank you Frank!

1.2G_DJ5AR_IK3HHG_20130219

Path DJ5AR – IK3HHG with planes and topography

As can be seen in the screenshot, the effective area is excentric to the center of the path. It is displaced southwards because IK3HHGs horizon is limited by the alps.

Ik3hhg

Eight times IK3HHG shifted by doppler, corresponding to the screenshot above

Last saturday at the GHz meeting in Dorsten Frank told me, that he integrated the groundtrack of the International Space Station to be drawn in the map too. So we have been discussing about the possibility of performing QSOs via reflections at the ISS.

ISS

AirScout with groundtrack of ISS

Back home I was very optimistic and used overflights, where the ISS  passed by nort of my location to look out for reflections of GB3MHL on 23 cm, but had no success. There was no trace at all in the waterfall diagram of my SDR. The duration of a pass is only up to 9 minutes and the expected doppler shift is +/- 84 kHz due to the high speed of 28000 km/h. So even if something could be heared or seen, tracking and decoding the signal will be another problem to be resolved.

But anyway: I am looking for somebody to perform tests with me, just to detect reflections at the ISS. Skeds are welcome via chat (ON4KST and HB9Q) or email dj5ar (at) darc.de

Review: Activity week Rhineland-Palatine 2013

January 14th, 2013

It was big fun working in contest for a whole week. I felt a bit like Phil Connors in the movie “Groundhog Day” (german: “Und täglich grüßt das Murmeltier”), in meeting most of the stations again day by day. My main activity was in the evenings on 23 and 13 cm, using 2 m, 70 cm and the ON4KST chat to arrange skeds. The conditions were slightly over normal but increasing on monday with a small opening to France. During the seven days I could work one new square on 2 m (JN15), two on 23 cm (JN09, JN15) and three on 13 cm (JN09, JO42, JO44). There were only two 4-band QSOs with DL7QY and DC1UR.

My top 5 of the most worked stations in this contest are:
DF8PR    16 QSOs on 3 bands (2 m, 70 cm, 23 cm)
DC8WPA   15 QSOs on 3 bands (2 m, 70 cm, 23 cm)
DK7UP    13 QSOs on 3 bands (2 m, 70 cm, 23 cm)
DL7QY    12 QSOs on 4 bands (2 m, 70 cm, 23 cm, 13 cm)
G3XDY     8 QSOs on 2 bands (23 cm, 13 cm)

Thank you all for your support and your patience!

Statistics:
        total      District K     DL ex K    France     I,OE,G,LX    Squares
Band    QSO Stn    QSO Stn DOK    QSO Stn    QSO Stn    QSO Stn      total new
 144    100  58     72  31  18     25  24      3   3      0   0        11   1
 432     65  31     54  22  15     11   9      0   0      0   0         6   0
1296     73  34     27   9   8     21  11     14  10     11   4        21   2
2320     28  15      2   2   2     14   8      5   3      7   2        12   3

Opening October 19th – 23rd

October 24th, 2012

The beacon check in the morning of October 19th gave me the impression of a strong inversion over southeast Germany. When looking for Stations on 23 cm on the SDR I noticed a big signal in CW: OE5VRL/5 calling to Hungary. I gave him a meep in the chat to tell him how strong his signal was here in Mainz, despite the fact that I was in the back of his 3 m dish. After turning the antenna to me he was stronger than many locals.

In the following days a lot of DX stations from OK, SP, HA, S5, OE, HB9, F, LX, G, PA, I and OZ filled the log while the inversion moved from east to west. All of the four OK beacons could be heard on 23 cm. Sometimes it was a little bit confusing when I was looking for new DX beacons and DB0AAT, DB0AJA, DB0GP, DB0LB, DB0FGB, DF0ANN, HB9EME and others could be heard in nearly any direction the dish was pointing to.

QSOs on 23 cm > 400 km

QSOs on 13 cm > 400 km

QSOs on 13 cm > 400 kmI am happy with a couple of new squares on 23 and 13 cm. Two new countries on 13 cm made it perfect: S51ZO in Slovenia and I1KFH in Italy. But I fear that it was more aircraft scatter than tropo.

Beacons heard on 23 cm

DB0AAT JN67HU
DB0AJA JN59AS
DB0FGB JO50WB
DB0GP JN48WQ
DB0LB JN48OV
DB0LTG JO31TB
DB0VC JO54IF
DB0WTT JO40LG
DB0YI JO42XC
DF0ANN JN59PL
DF5AY JN49DX
F1XBC JN06JG
F1ZBK JN38BP
F5XBK JN18JS
HB9BBD JN47GA
HB9EME JN37KB
OK0EA JO70UP
OK0EJ JN99FN
OK0EL JO70SQ
OK0EQ JN89BE
PI6ASD JO22KJ
PI7ALK JO22IP
SR6LHZ JO70SS

NAC(?) 23 cm – October 2012

October 16th, 2012

The Nordic Activity Contest is always a very good opportunity to work . . . Italians!

Tonight everything was upside down. After loosing John, G3XDY in QSB – a fact that is very, very strange – I wanted to turn the dish via south to north, when Sergio, I1KFH was meeping me. We tried and had our QSO in SSB. What else to say? Giorgio, IK3GHY followed as well as Robert, IZ4BEH and Frank, IK3HHG and Walter, IW2BNA and finally Roberto, IK2OFO.

Mille grazie. Buona notte!

NAC to Italy

NAC to Italy

Contest results on 23 cm: 1990 vs 2012

October 11th, 2012

My operating conditions have changed quite a lot compared to October 1990. But my QTH is still the same in the south of Mainz, JN49CV. The most serious circumstance is, that we have internet and software defined radios nowadays. The possibility to arrange skeds and to gather information is revolutionary. It´s easy to find stations in the waterfall diagram, that are not on your frequency. No more CQs for hours and hours. Instead the chat must be watched and skeds will be arranged.

QSOs in October contest 1990

Rig: 1.2 m dish / 10 m RG213 / 120 W

Claimed result: 78 QSOs, 12000 km, ODX 404 km

 

QSOs in October contest 2012

Rig: 3 m dish / 3.5 m ecoflex 15 / 0.4 dB preamp / 10 m ecoflex 15 / 200 W

Claimed result: 53 QSOs, 18000 km, ODX 725 km

 

IARU-Region-1 UHF/Microwaves October Contest

October 8th, 2012

“Bad weather and bad conditions” that is, what most comments say about this contest. The weather here in Mainz was bad too, but I cannot compare the conditions with the contests in the last years, because my last participation in this contest was in 1990. This year it ended up in 50 QSOs on 23 cm and 19 on 13 cm. I am quite satisfied with these results.

QSOs on 23 cm

 

QSOs on 13 cm

My new ODX on 13 cm is OL9W in JN99CL over 720 km. A lot of new squares could be worked too. Many DX stations were nearly as strong as they were on 23 cm.

NAC 13 cm – September 25th 2012

September 26th, 2012

Because the NAC on the fourth Tuesday each month promises good activity on 13 cm, I installed the new 75 W solid state linear and turned the dish to Scandinavia. Despite the QRM on 13 cm around here (may be from WLANs) and the Taunus mountains about 25 to 30 km north of Mainz, I was very pleased to work DL1SUZ in JO53 (471 km), G3XDY in JO02 (547 km), OZ3ZW in JO54 (583 km), DL0VV in JO64 (538 km) and OZ1FF in JO45 (633 km) on 2320 MHz.

QSOs on 13 cm – QRB > 400 km