Some Holiday fun from the Danish coastline. Reception of orbiting weather satellites on 137 MHz and 1.700 MHz. These weather satellites have an orbital altitide of approximately 820 km and a transmit power of 5-10 W EIRP (137 MHz) resp. 10-20 W EIRP (1.700 MHz). Equipment: V-dipole / 60cm Offset dish with SDRplay and low-noise preamp for 1.700 MHz.
There are a lot of further Informations about HRPT Reception on the web, this web page is very much recommended!
Nowadays, every household has at least one paper printer for everyday use. As a radio amateur, a 3D printer is also essential and helpful. I’d been toying with the idea of purchasing one for a long time, and now the time has come. Today, after a good four weeks, I can’t imagine life without it. Whether it’s a finished file from the internet that’s being printed, or a self-constructed housing, a mount, or a broken plastic part that needs to be reconstructed because it’s no longer commercially available.
Working via the moon on 23cm with my small, 1.75m diameter dish is possible, but sometimes difficult. Stations with a dish diameter of 3.0m and above were easy to work with, as were smaller ones down to 1.8m, provided they were optimally configured.
In recent months, the popularity of foldable 2.4m dishes has increased significantly. These antennas are equipped with a disc patch feed and a 90° hybrid coupler to provide circular polarization. To switch between LHCP and RHCP, a power relay and a set of cables are required. This combined effect causes noticeable losses. During EME experiments with such stations, I noticed that they are significantly weaker and less sensitive than comparable 2.4m stations equipped with septum feeds. For this reason, it was often very difficult, if not impossible, to complete a successful QSO with them.
1.75m solid Dish expanded to 2.35m
Therefore, I decided that it was time to enlarge my solid 1.75m dish. First, the parabola was calculated and a template was created for the new intended size. Enlarging the dish results in a reduction in the f/D (focus/diameter). As a compromise, I opted for a new diameter of 2.35m, which corresponds to an f/D of 0.31 (previously 0.38). Good illumination with the existing septum feed is still given. The calculated additional gain resulted 2.5 dB for received signals and about 5.0 dB for my own EME echoes.
After completing the expansion, solar noise measurements showed an increase of Sun noise between 2.5 and 3.0 dB, which corresponds to the calculations. This was also noticeable in practical operation; stations with folded 2.4m dishes as well as stations with Yagi antennas can now also be worked, provided they are well optimized.
A great, enjoyable afternoon and small JA3-EME-Meeting happened in Kyoto / Japan today with my friends (left to right) Taka-san JP3EXR (2m EME), Koji-san JE3GRQ (6m/2m EME), myself and Kay-san JH3AZC (2m/23cm EME).
In addition to the large amateur radio fairs in Friedrichshafen / Germany and Dayton / USA, the Tokyo Ham Fair in Japan is by far the largest of these exhibitions. In 2024, it recorded a new record with around 45,000 visitors. I had long planned to travel to Japan and visit the Ham Fair. This year, it finally worked out. The new exhibition hall “ARIAKE GYM-EX” is located directly on the Pacific and is convenient and easy to reach by public transport.
The following pictures give a small impression of this great exhibition.
It was a great pleasure for me to meet many well-known DX’ers in person and to make new friends. See you in Tokyo or see you again on one of the amateur radio bands.
Today it finally happened! After almost a year and many difficulties with the shipping, it has arrived: the “Russian Districts Award 2500 Honor Roll” plaque. Russia is divided into a total of 2.642 oblasts (districts), also called “RDA”. The plaque is awarded for confirmed radio contacts with at least 2.500 of theses RDA’s. If you have further interrest have a look here: http://rdaward.ru
During my stay in Bangkok in November 2023, I had the opportunity to meet probably the most famous and successful radio amateur in Asia: Champ E21EIC and his lovely wife Goi, E20NKB. Champ is not only known by his own call sign, but also by E2A, under which he and his crew wins almost every major contest in Asia. In addition, he is probably known to most active DXers through many DX expeditions like XW1IC, XW4XR, 3W3B, OJ0A, HS60RAST to name just a few. Thank you Champ and Goi for the lovely day and the meal together. We’ll meet again soon!
144 MHz DXCC – all Countries worked with just one single Yagi Antenna
How it all began …
A long time ago, sometime in 1980, I observed my friend Fritz Herbst near Hanover, DL3YBA, doing echo tests on 144 MHz via the moon with his huge antenna array. At that time, of course, there were no digital modes of operation, telegraphy was the way to go. I used a 16 element Yagi from Tonna (F9FT), that was state of the art. Of course I didn’t hear His echoes, but it got me interested in EME (Earth-Moon-Earth) experiments. Time passed and many unsuccessful attempts followed. Then on April 03, 1982, the moon was close to the western horizon, I suddenly heard the CW signals from Dave K1WHS – unbelievable!. At that time he had the largest 2m system in the world with 24 x 14 antennas. I called him in CW with my 500W into the 16 Element and .. whooow .. we made a QSO! Unfortunately, this was to remain my first and only EME contact for many years. In 1988 there was another EME contact with Dave, W5UN in Texas (holder of 2m DXCC #1). With his superstation of 32 x 17 element he made an incredible signal via the moon. But then the game of 2m EME was over for me. With just one antenna it was not possible to work others beside those two Superstations and there was no space for a group of four yagis on our property.
It was summer 2017 when I met my longtime radio friends OK1DIX, OK1VPZ and OK1TEH at a ham meeting in Poland. They raved about the possibilities of successfully doing EME with the JT65 digital operating mode. I got hooked again! When I got home, a new antenna was ordered, I decided on a 14 element Yagi from AnjoAntennen with a length of 6.7m and a gain of 13.5 dBi. A short steel pipe was concreted in the garden, the rotor was put on and the Yagi was fastened. Despite the short cable of about 15m, I mounted a preamplifier (HA8ET) near the feedpoint. When Beko’s SSPA arrived, things could get going. In the meantime, the EME world could not be imagined without the digital operating mode JT65 from K1JT and that was a quantum leap compared to telegraph operations.
On August 26, 2017, I finally got going with just one antenna into the new EME world. I had set myself the goal of working a total of 10 different stations. To anticipate, that was already done on the second day. The target was revised upwards and upwards, 100 stations, 250 stations, DXCC! Nevertheless, EME with only one antenna is a hard way and in a pileup you are always the very last in the long line of callers. Of course there were setbacks at the beginning and a lot of new things to learn. In the first few months things progressed quickly, many new DXCC countries entered the log. However, due to the Covid crisis, these stopped in 2020 and a long boring periode began. Then finally, on November 12, 2022, a QSO with ZC4RH succeeded and the long-cherished dream – my 144 MHz DXCC Award was completed!
Back in 2019 Lee, WW2DX, and Team activated the rare DXCC St. Paul Island on 144 MHz via EME under the callsign CY9C. This year Sable Island was his destination, CY0S the callsign. With the proven equipment of 2 x 9 Element Hpol and Amplifier, Lee was in the air for a few days. The moon was not in a favourable position but after the first rush of callers was over, I managed to get a contact and my DXCC #101 on 144 MHz was in the book. Thanks Lee for another great QSO!
Today
a big dream came true: the 100th country on 144 MHz is in the book. It
was a long and rocky road, but time and effort paid off. It’s only the
3rd time a single yagi station has reached this mark (as far as I’ve
researched). Many thanks to the team at ZC4RH (Dave, Chris and Jos) for
their effort and contact via EME!
