Presentation “Let´s Bounce”

On July 24th, 2014 on 19:00 CEST I will talk about how to surmount the horizon on VHF and up at the local DARC Club in Bodenheim near Mainz.

After giving an overview over the classic propagation modes Es, Aurora, MS and Tropo, I will explain, how aircraft scatter and ISS bounce work. EME will be subjected too and the presentation will be completed by an introduction to “Visual Moonbounce” as performed by Daniela de Paulis.

Deutscher Amateur-Radio-Club e.V.
Ortsverband Bodenheim
Haus der Vereine
Laubenheimer Str. 22
55294 Bodenheim

The admission is free, but please register via email to
DK2FQ (at)   or to me   dj5ar (at)

Article in “Funkamateur” magazine July 2014

German Funkamateur mgazine has published my article “Abenteuer Bakenbeobachtung von 144 MHz bis 10 GHz” in its recent issue July 2014. As many topics are related to posts on this website, some of them are compiled here. Links to certain other websites can be found in the link list to the right.

Weather, rainscatter:

Rainscatter on 23 and 13 cm
Impressive Thunderstorm

Weather, troposheric ducting:

Another strange constellation (Update)
Strange Conditions
Opening September 21st 2013

Aircraft scatter (video):

PI7ALK via Aircraft Scatter

List of beacons, heard by DJ5AR in Mainz, JN49CV

My new beacon list

Impressive Thunderstorm

2014-06-09 db0aja RS
The destructive thunderstorm in the Köln/Düsseldorf area last night was intense enough to provide rainscatter even on 1.3 GHz. DB0AJA near Würzburg in JN59AS could be heard with the typical rainscatter sound when the dish was heading 325°. An awful lot of water must have been in the air. The total distance of the signal path was about 400 km (150 + 250).
2014-06-09 21_18_29-PowerSDR-DB0AJA RS

The waterfall shows the spread of the signal. DB0AJA runs 20 W output into a 16 element Flexa yagi beaming northwest.

Meteor Scatter: Back in Business!

Since I will be back in Ireland in August, I plan to be QRV for the perseids on meteor scatter, activating my irish callsign EI8HH. The location is in Clonbur, Co.Galway, IO53HN. My equipment will be a FT-897 with 50 W into a 17 element yagi (F9FT) on 144 MHz.

My last MS QSOs dated back to 1989, when high speed CW was state of the art. To gather some experience with WSJT and FSK441, I watched the 144.370 MHz and worked YO9MN and GM6VXB randomly.
Another test with GM4ZJI couldn´t be completed, because we had to leave for QRL. But I got a nice burst from him at the end of our try:

065730 12.5  260 13 27 -158   FO5AR GM4ZJI 26 26 DJ5AR GM4ZJI 26 .9C$H
065730 12.8  840 10 26 -151   DJ5AR GM4ZJI  7    DJ5AR GM4ZJI 26 26 D
065730 13.8  120  2 26 -158   J AR GM4ZJI #6 / ,C

Later I worked Dermot, EI7IX, from Westport, very close to my irish QTH (a compilation of his bursts):

094000 17.7  340 13 27  -43   73 EI7IX 73 EI7IX 73 EI7IX 73 EI7IX 73
094100 11.9  520  6 26  -58   NX/73 EI7IX 73 EI7IX 73 EI7IX 73 EI7IX
094100 25.3  440 11 27  -41   YX 73 EI7IX 73 EI7IX 73 EI7IX 73 EI7IX 7

Visual Moonbounce

The italian-dutch artist Daniela de Paulis is the inventor of visual moonbouce. Slow scan television is used to send pictures towards the moon. When the bounced signals will be received and visualized, the pictues are a kind of distorted and win a very special charm.

The pictures shown below are screenshots, I took during a performance on April 13th, 2014.

2014-04-13 visual Moonbounce 1 2014-04-13 visual Moonbounce 2I am very proud, that Daniela has choosen one of my pictures for her performance. It shows the moon resting on clouds and has been bounced at the moon.

Nando, I1NDP, transmitted a selection of pictures in SSTV, to be received by PI9CAM with the radiotelescope at Dwingeloo. Using a “GOOGLE Hangout”, an audience from all over the world watched live, how Daniela and her team (Nando, I1NDP, Jan, PA3FXB, and many more) were bouncing all the pictures at the moon.

A video recording of the session can be found here.

Reopening of Dwingeloo 25 m Radiotelescope


DSC_0383a After an extensive restoration by ASTRON and the CAMRAS foundation, the 25m dish of the radiotelescope in Dwingeloo has been reopened by astrononomer, radio amateur and Nobel laureate Prof. Dr. Joseph Taylor, K1JT, on April 5th, 2014.

DSC_0258In future it will be used by radio amateurs, amateur astronomers and artists for certain projects.

NAC/IAC in March

Last night I have been active in the Nordic and Italian Activity Contests on 13 cm. The conditions were awesome. Just four QSOs with IK2OFO (JN45), IZ4BEH (JN54, new #), DL0VV (JO64) and OZ3ZW (JO54) were written to the log, very weak Signals and rare airplane reflections most of the time. So it needed much patience and certain aircrafts to complete the QSOs as the audio record of my QSO with Roberto, IZ4BEH, shows.

It demonstrates my style of operation in aircraft scatter QSOs. I keep the transmissions short and listen in between. Only relevant information will be sent, because the duration of a reflection is typically very short. Fixed periods in aircraft scatter tests are not required at all. The first signals, received from Roberto, included the callsigns and fractions of a report. So I could be sure, that both calls were exchanged and only the report was needed. The locator was sent too, because IZ4BEH has been working in the Italian Activity Contest. It took quite a while, until a second airplane passed by near the midpoint of the path, giving us the chance to complete the QSO.

After my recent complainment about the challenge of the chat in March Contest, I got emails from Claus, OZ1FDH, and Kjeld, OZ1FF, with information about KST2ME, a tool to manage the ON4KST chat. I made use of it in the activity contests and it is a real improvement compared to the pure webclient. Thank you, Claus and Kjeld, for the feedback! KST2ME can be downloaded from Bo´s, OZ2M, homepage.

PI7ALK via Aircraft Scatter

One of my favorite beacons to be watched via aircraft scatter is PI7ALK in JO22IP.  The beacon is running 4 W to a 4 times stacked omnidirectional antenna as described in DJ9HOs “UHF Unterlage V” on page 1001. The design of the antenna is by DC0BV.

After about a minute first reflexions can be seen. The signal is increasing in strength, until the plane reaches the midpoint of the path.

VHF-UHF-SHF Contest March 2014

Many thanks to all enthusiasts on 23 and 13 cm, who spent up to 20 minutes to complete a QSO with me. Tropo conditions were not too good this time and especially 2320 MHz it seemed to have an additional attenuation on all signals. But never the less, quite a lot of QSOs filled the log. More stations than I could handle, requested skeds via the ON4KST chat. I have to apologize for all my replies like “pse qrx, meep u when free”, I forgot about. So, all I can say is:

Please excuse me for forgetting to meep you!

Indeed, this chat is a great tool, I don´t want to miss it. But in times of contest it can be a challenge, like the contest itself. I will not apply for to do without, it is rather a question, how to use it. The amount of information, flowing over the screen, is immense. On saturday afternoon or on sunday morning, relevant entries might disappear within less than a minute. So I have to think about optimizing my software tools.

QSOs on 1296 MHz

Skilled VHF Operators may smile, when I tell them, 58 QSOs on 23 cm and 19 QSOs on 13 cm are hard work. The sum of that is the number they work within the first hour of their contest section. But in fact, the world above 1 GHz is a different one. The beams of the antennas are much narrower compared to VHF and UHF. The dense of stations is much less, since it is not like plug and play to become QRV up there. The attenuation increases GHz by GHz and all that results in real work for most of the QSOs. There are only a few big guns on 23 cm to be heard from any antenna direction. So the band seems to be empty, even at contest time. But the chat is an oppotunity for all kind of stations to arrange skeds and to have QSOs over distances of several hundred kilometers. And, especially when using aircraft scatter, patience could be needed to complete.

QSOs on 2320 MHz

ISS Bounce even in SSB

After getting familiar in working us in CW via ISS Bounce, Jan, PA3FXB and I were looking for a new challenge. So we decided to try it in SSB. After some tests in the last days and finding a workaround for a bug in my PowerSDR, we completed a two way contact in SSB on a center frequency of 1296.300 MHz tonight. The doppler compensation worked well on both sides. Just minor corrections with the RIT were neccessary. The signals weren´t as strong as they were in the days before, but strong enough to copy even some 73s at the end. It seems to be the first SSB QSO via reflections on a spacecraft at all.

The audio recording starts with my recording of PA3FXB on one channel synchronized with Jans recording of my signal on the other channel.