Tag Archives: beacons

Presentation “Let´s Bounce”

June 22nd, 2014

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.

Location:
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   wolfgang.beer (at) gmx.net   or to me   dj5ar (at) darc.de

Article in “Funkamateur” magazine July 2014

June 22nd, 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

June 10th, 2014

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.

PI7ALK via Aircraft Scatter

March 17th, 2014

One of my favourite 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. More details and the history of the beacon can be found here.


After about a minute first reflexions can be seen. The signal is increasing in strength, until the plane reaches the midpoint of the path. While other planes join, the signal will be spread by the doppler effect.

Another strange constellation (Update)

February 6th, 2014

While performing my beacon check on December 16th, 2013 at 8:30 UTC, I stated that all beacons seemed to be at a normal level. Except, when looking for DB0FGB (JO50WB) with the dish heading 85°. There was a constant carrier of about 20 dB 15 kHz up, keying F1ZBK (JN38BP). Expecting a big signal, I turned the dish to France. But the beacon was only 15 dB with QSB, when beaming directly to it at 228°. Then I turned the dish back to 85° and noticed, that HB9EME (JN37KB) joined the party.

2013-12-16 09_30 F1ZBK HB9EME 85deg

DB0FGB, F1ZBK and HB9EME with dish heading 85°

The rain radar didn´t show anything unusual and the F5LEN Refractive index forecast for Europe promised only marginal tropo conditions for this area. Only DL7QYs Condition Index for south Germany has been on a level of 7 (1 = poor; 10 = extreme).

2013-12-16 09_00 F5LEN index

F5LEN Refractive Index

DB0FGB was a bit above normal at about 15 db with little QSB up and down. F1ZBK was constantly at 20 dB, when beaming 85° and around 15 dB with QSB heading 228° (direct). HB9EME was up to 20 dB in 85° and peaking 15 dB in fast QSB when beaming 198° (direct).

Green: Paths from Mainz to the beacons
Orange: Paths of the beacons to the area of the supposed reflection point

I checked HB9BBD, F5ZBS, F1ZBI and others, but couldn´t see any similar effects. The angle was very small. When turning the 3 m dish 5° left or right, the signals disappeared. These conditions lasted for about one hour.

Path DJ5AR to DB0FGB (by AirScout)

Topographic profile between DJ5AR and DB0FGB

The horizon in 85° is about 80 to 90 km off. A plausible explanation could be a strong troposheric duct between the beacons and a reflecting topographic formation.

Update:

In issue 2/14 the german magazine “Funkamateur” published an article by Matthias Hornsteiner, DG4MHM “Prognosekarten für troposphärische Überreichweiten” (Prediction maps for troposheric ducting). Matthias explains the basics of ducting and analyses the models, the well known refractive index maps of F5LEN and W. Hepburn are basing on.

So I had the intention, to ask him about a possibility for a reconstruction of the wheater constellation of that day. I have to thank him very much for his comprehensive answer.

As Matthias explained, the situation, shown on the map, was quite common for this, as he describes it, “anti-winter”. But it holds the possibility, that warm air might glide onto cold air at ground level. And indeed, when he reviewed the data of weather balloons launched at Stuttgart on that day, he found indications for a strong inversion in an estimated level of 400 to 600 m over south Germany. That matches!

In a distance of 200 km from here, the the topographic profile shows a formation, high enough to reach the level of this duct, as well as the mountains of the Fichtelgebirge do, where DB0FGB is located. The distances from Mainz to the area of the supposed reflection point is between 200 and 250 km. From F1ZBK and HB9EME it varies between 400 and 500 km. So the total path should have been between 600 and 750 km.

 

Strange Conditions

December 11th, 2013

It is funny to check the beacons tonight. Most remarkable are two constellations, shown below:

2013-12-11 21_59 DB0VC and DB0AAT

While looking for DB0AAT in JN67HU, DB0VC in JO54IF could be received too. When beaming to Kiel, DB0VC can be heard even on 2320 MHz. It is beacon #9 on 13 cm.

 

2013-12-11 22_23 DB0NCO beats DB0FKS

DB0NCO beats Frankenstein

From my QTH DB0NCO has the same bearing as DB0FKS. The location of DB0FKS, the  Frankenstein Castle, can be seen visually from here in a distance of 34 km. DB0NCO is 203 km away but tonight it is stronger than DB0FKS, when coming up in QSB.

Opening September 21st 2013

September 21st, 2013

While performing a last beacon check before going to bed and all local beacons were quite normal, I took notice of a weak carrier 1 kHz up of F1ZBK on 1296.855 MHz. After optimizing the antenna and using a narrow filter I heard EA2TZ in IN93BF over 1073 km for the first time ever.

2013-09-21 20-50 EA2TZ

Left signal: F1ZBK/B, right signal: EA2TZ/B

 EA2TZ/B as received by DJ5AR over 1073 km on 23 cm

After posting this information in the ON4KST chat, Matej, OK1TEH sent the phone number of EA2TO and told me that Javier is currently QRV on 23 cm from IN83. After exchange of a few SMS he came back on my CQs and we could complete a QSO: A new DXCC, a new square and a new tropo ODX of 1173 km on 23 cm!
When closing down the station I had a quick look on 70 cm. There he was again: EA2TO in SSB. We had a nice chat and for me: A new DXCC, a new square and a new ODX of 1173 km on 70 cm!

Only 2 QSOs tonight, but I am very happy with it.

Rainscatter on 23 and 13 cm

June 20th, 2013

While performing my daily beacon check, a strange constellation around 1296.850 MHz appeared on the display of my SDR. The dish was turned to 254° at that time, to look for F5XBK.

2013-06-19 RS F5XBK F1ZBK ON0NR HB9EME

From left to right: F5XBK, F1ZBK, ON0NR, HB9EME

Combined with strong QRN and radar noise I could copy F5XBK in JN18JS quite normal via tropo but also F1ZBK in JN38BP, ON0NR in JO20KJ and HB9EME in JN37KB via a rain scatter point in JN39LP. Later DB0GP in JN48WQ and DB0AJA in JN59AS could be heard too.

Then I continued to have a look on 2320 MHz where DB0UX in JN48FX, DB0FGB in JO50WB and DB0MJ in JO31UB could be copied via a scatter point in JN39JR.

Beacons heard via rain scatter on 23 and 13 cm

The map shows the location of DJ5AR in Mainz (green marker) in relation to the scatterpoints (blue markers). The paths to the beacons on 1296 MHz are in light blue and on 2320 MHz in dark blue. For that time heavy thunderstorms with flooded roads and cellars were reported for the area of Hermeskeil in JN39.

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.