Tag Archives: Mainz

Presentation “Let´s Bounce” II

September 1st, 2014

ISS Bounce Title

After giving the presentation in english language in Clonbur, Ireland on August 25th, there will be two more dates in Germany:

September 13th, 2014 at the VHF/UHF/SHF Convention in Weinheim as a short version.

September 27th, 2014 at the “Distriktsservicetag” of DARC districts K (Rhineland-Palatine) and Q (Saarland) in Saarbrücken.

I will talk about how to surmount the horizon on VHF and up.

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.

For the short version in Weinheim the overview over the classic propagation modes will be left out.

Reception of HAM TV aboard the ISS

July 31st, 2014

At present the HAM TV transmitter aboard the International Space Station performs blank transmissons until August 6th, 2014. No camera is attatched, so only signal levels can me measured.

This was an opportunity for me to check out the FSTV-equipment, I set up during the last months. So my very first attempt last night was successful. I used the pass at 23:50 UTC on July 30th, 2014.

I am looking forward to see some pictures in near future.

Reception of ISEE-3

July 30th, 2014

For quite a while now I try to catch a signal of ISEE-3. Because of severe thunderstorms, there was no opportunity to check out yesterday. But today (July 30th, 2014) is the day to listen to this 36 year old bird.

The signal of the beacon on 2,270.414 MHz isn´t too strong, but clearly audible in the speaker. The actual distance is about 1.6 million km, the furthermost man made signal I ever received!

The downlink transponder A on 2.270.4 MHz uses an antenna array with a gain of 7 dBi, a beamwidth of 12° and circular polarisation. The nominal TX power is 5 W.

The equipment I am using, is just a FUNcube Dongle Pro with a 13 cm ATV converter (LO 916 MHz, IF 1,354 MHz) and a 13 cm LNA near the 23/13 cm dual band ringfeed at my 3 m dish.

Frequency calibration is performed on ordinary 13 cm beacons like DB0UX. The dish calibration is done by optimizing sun noise on 23 cm or the levels of SIRIUS satellites on 13 cm.

The rhythmical fading of the signal seems to be caused by the space probe´s spin of 19.76 revolutions per minute.

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.

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

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).

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!

May 8th, 2014

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

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.

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).

$F5LEN Refractive Index$

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.

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.

Review: Activityweek Rhineland-Palatine 2014

January 8th, 2014

The battle is over. I had my last QSO with Patrick, DH2PA on 70 cm just before the contest closed after seven days. There was a big regional activity on VHF, UHF and SHF, much more than last year. Finally I logged 414 QSOs on the four bands I have been active, compared to 266 in 2013. It is remarkable that there were many locals with improvised equipment on 23 cm. Just one new square on 2320 MHz could be worked during the activityweek: IK3GHY in JN65DM via aircraft scatter. But collecting new squares is getting harder and harder, the more are already worked. The tropo conditions remained normal during the seven days, so there was less DX than last year. This time I found four partners for 4-band-QSOs: DL7QY, DL8YG, DF5AY and DB6NT.

The top five of the most worked stations in this contest:
1. DL7QY    24 QSOs on 4 bands (2 m, 70 cm, 23 cm, 13 cm)
2. DC8WPA   18 QSOs on 3 bands (2 m, 70 cm, 23 cm)
   DJ1FZ    18 QSOs on 3 bands (2 m, 70 cm, 23 cm)
   DK0RLP   18 QSOs on 3 bands (2 m, 70 cm, 23 cm)
   DK7UP    18 QSOs on 3 bands (2 m, 70 cm, 23 cm)

Thank you all for your support and your patience!

Statistics:
        total       District K      DL ex K    F,I,OK,OZ,SM   Squares
BAND    QSO Stn     QSO Stn DOK     QSO Stn     QSO Stn       total new
 144    183  94      99  43  26      82  48       3   3          15
 432    134  66      69  31  20      65  35       0   0          10
1296     79  37      36  14  12      34  16       9   7          16
2320     19  11       1   1   1      15   7       3   3          10   1