AirScout V1.3.3.0 released

May 3rd, 2020

The VHF/UHF/SHF contest on 2nd to 3rd of May was a good opportunity to spend a few hours trying the new AirScout version released by Frank, DL2ALF. In principle it works like it´s predecessors, but is more stable in collecting the aircraft data. My favourite in this case is

Most impressed I am by the new feature to monitor a number of paths to certain stations simultaneously! This provides more efficiency in arranging skeds, particularly in times like these, when there are a few planes only are available.

Find more details on the AirScout Site.

Side Scatter Test on 13 cm

January 22nd, 2020

Tonight I met Salvo, DK3SE, in the ON4KST chat. Salvo recently became QRV again on 13 cm. He uses a 1.8 m dish and has about 50 W at the feed. As his location is on the southern slopes of the Black Forrest, our direct path is blocked by solid rock. Even aircraft scatter is very hard to perform.
So we tried to find a reflective point at the mountain range of the Alps, but that was not very satisfying as well. Next step was to try side scatter on airplanes to the east of the Black Forrest.

Side Scatter between DK3SE and DJ5AR

We tried on a couple of planes and, as expected, on the ones, we saw the same side of the body, we received strong reflections. So we learnt, in side scatter the orientation of the plane matters! This is in opposite to the usual aircraft scatter, where the planes just have to be on the path and the bottom side of the aircraft is used as reflector.

Strange Conditions Today

January 1st, 2020

I got up quite early today and decided to check the beacons on 23 cm. When beaming to LA1UHG, there was a noticeable signal in F1 about 1 kHz above its frequency. It was easy to read it as DB0LB from the back of the dish. But it seemed, there was another faint signal right beside the spacing carrier. With the help of my SDR radio I could set very narrow filters and after a while of listening, I identified it as LA1UHG, JO59FB, 1028 km. Wow!

But the signal faded out more and more and at least it disappeared.

LA1UHG just 140 Hz below the space carrier of DB0LB

Later this morning, the dish still pointing north, I heard Kurt, OE5XBL, chatting in SSB with Rudi, OE5VRL/5, both with very strong signals on 23 cm. Expecting a huge signal, I turned the antenna to Kurt, but there was no significant increase in signal strength. I called in and the three of us were talking about the conditions and to meet for a beer at the GHz convention in Dorsten next February, when Kurt was called by Dave, G4RQI. I had tried with him earlier without any success, and so, to be honest, I was a little annoyed by this. Even, when turning the dish to the UK, I couldn´t copy anything of Dave’s transmissions, while he was working Kurt and Rudi. These were enough indications, that the inversion was at a too high altitude for me, to enter it. So I went for a long walk with my XYL in the nearby vineyards.

The inversion is at an altitude of about 1000 m (Courtesy DWD)

In the evening I performed another beacon check. It was funny to see beacons, the dish was pointing to, as well as others from the back of the dish

Dish pointing southeast: DB0UX, DB0VC, DB0AAT (from left to right)

Turning the dish, confirmed the experience I had in the the morning: Pointing southeast I saw DB0VC, JO54IF, next to DB0AAT, JN67HU. Turning the dish towards Kiel in the north, the signal of DB0VC increased just a little. Maybe, it has been reflected by a mountain range about 50 km southeast of me.

Dish pointing north: DB0UX, DB0XY, DB0VC, OZ7IGY (from left to right)

F5ZNI: Beacon #34 on 13 cm

December 29th, 2019

By performing my daily beacon check, I noticed a weak keyed carrier in between the spacing of the F1 signal of DB0UX on 2320.900 MHz. I assumed to see F6DWG/B, which I monitored around the .900 before. But it didn´t take long to find out, that the real signal (mark) was the lower carrier and after a while I learned, it was F5ZNI using reverse F1 keying. Later in the evening the signal increased due to good tropo conditions, as can be seen in the pictures. F5ZNI is the 34th beacon I received in the 13 cm (S) Band

F5ZNI and DB0UX in PowerSDR

I am always happy about new beacons, but this case is an example, why beacon coordination and using standards is most important. First of all, reverse F1 keying is always bad, as you are used to listen to the upper carrier of the signal. In case there is an unkeyed carrier in between the text, you can easily identify the mark, where to listen. But if there is text keyed nearly all the time, as F5ZNI does, it is rather time consuming until the mark is identified.

The DB0UX signal was strong and the frequency is locked to a reference, while F5ZNI is drifting a little. So it was obvious, that there was a second signal in place. If the french beacon would have been locked to 2320.900 MHz too and would use the standard A1 or F1 keying, there would have been no chance for me to monitor or even to take notice of it.

An excerpt from BEACONSPOT.UK shows the situation on 2320.900 MHz:

BeaconNominal FrequencyLocatorLast SpottedLast FrequencyStatus
OZ5SHF2320.900JO45VX2019-08-242320.900Operational on spot date
DB0UX2320.900JN48FX2019-12-292320.900Operational on spot date
F1ZCC2320.900JN08XSUncertain - new spot required
F5ZNI2320.904JN19BQ2019-12-302320.899Operational on spot date

Depending on the location and the conditions, there will be more or less interference on 230.900 MHz

So I am urging all beacon keepers to make use of the service provided by the
IARU R1 VHF/UHF/MW Beacon Coordinator. When designing a beacon, please respect chapter 11 “Beacon Requirements” in the IARU-R1 VHF Handbook.

DB0XY back on Air

December 17th, 2019

As the beacon keeper Thomas, DL4EAU, wrote me, the DB0XY beacons in JO51EU are back on air. The frequencies are 1296.912, 2320.912 and 10368.912 MHz. All are locked to a GPS reference now.

DB0XY on 1296.912 MHz in JN49CV: A weak tropo trace, but many nice reflections on airplanes
DB0XY on 2320.912 MHz: No trace via tropo, but many reflections on planes

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!

After a Year of Absence: Back in Business!

July 7th, 2019

The last contest, I participated, was in June 2018. There wasn´t much time for amateur radio since. So I was lucky to dive into contesting this weekend mainly on 23 and 13 cm, as usual, but had some QSOs on 2 m, 70 cm and 3 cm as well.

I am happy about 60 claimed QSOs on 23 cm and 43 on 13 cm. On 3 cm I logged 7 Stations, with OE5VRL/5 as ODX via rain scatter.

QSOs on 23 cm
QSOs on 23 cm

There have been some new calls on 23 cm but none on 13 cm, as I had expected. Many became QRV on 2400 MHz for QO-100, using transverters, also operable on 2320 MHz. They should learn about the exitement of DX via aircraft scatter on 13 cm.

QSOs on 13 cm

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.

Playing with the bird

April 1st, 2019

As soon, as the narrow band transponder was opened in February, I had my first QSOs via QO-100. Using an MKU LNC 10 in a 80 cm offset dish and my 3 m mesh dish for transmitting, made the first steps very (too) easy.

ADALM Pluto and 2 LNAs mounted at a W2IMU feedhorn

In the meantime I mentioned, some hams from the Netherlands, experimenting with ADALM-Pluto SDRs, had very good results. So I got one too and was amazed of variety of possibilities it offers. So I heard my first beacon on 9 cm and it was easy to produce a signal on 13 cm. Recently I got two broadband LNAs (I will call them “A” and “B”) from China and was curious to see how these can be used as power amplifiers too.

Power SourcePower in mW
Pluto 3
Pluto + LNA "A" 22
Pluto + LNA "B" 30
Pluto +LNA "A" + LNA "B"120

After some power measuring I connected the stuff to a W2IMU feedhorn, mounted on a tripod. No problem at all to find my signal on the NB transponder of QO-100. The estimated EIRP is about 2.4 W and results in a signalstrength of 12 dB.

Addendum: April 10th, 2019

3 mW are enough!

At least I mounted a DJ7GP patch feed with the bare naked Pluto in the focus of my 3 m mesh dish. the 3 mW were enough to produce a solid signal on the NB transponder. In this case I have 6 W EIRP to get 16 dB signal.