Recovering an RS92-SGP radiosonde

A few days ago, I talked about the radiosondes that are launched every 12 hours from Madrid-Barajas Airport. Yesterday, I went with my mother on a trip to try to recover the radiosonde that was launched at 11:00UTC. This radiosonde managed to ascend to 31000m before bursting. This is quite high for a radiosonde of this kind, as they usually burst between 24000 and 28000m.

We left home at 13:00UTC, so the radiosonde was quite far from us by that time. The last telemetry we managed to decode was when the radiosonde was 3800m high and on its way down. It was flying over Sacedón, in Guadalajara, and slowly drifting eastwards along the road. We were still on our way to Guadalajara, more than 40km away.

Continue reading "Recovering an RS92-SGP radiosonde"

Receiving the Vaisala RS92-SGP radiosonde launched from Madrid-Barajas

Each day, at 01:00UTC and 11:00UTC a Vaisala RS92-SGP radiosonde is launched from Madrid-Barajas airport. This is a small electronics package tied to a helium balloon that ascends up to between 24 and 28km high before bursting and descending on parachute. It is designed to measure atmospheric parameters on its way up. It includes temperature, pressure and humidity sensors, as well as a GPS receiver. The launch on Wednesdays at 11:00UTC also includes a plug-in ozone sensor (which is a much larger and more expensive package). The data is transmitted at 403MHz using Manchester-encoded 4800bps GMSK and protected using Reed-Solomon. You can find more information about the RS92-SGP model in its technical datasheet and about the launches at Madrid-Barajas and other launches in Spain in the Spanish AIP Section 5.3 (other activities of a dangerous nature). Also, there is somebody who feeds the radiosonde data into the APRS network using SM2APRS, so you can track the launches by following OKER-11 on aprs.fi.

Usually, the Sondemonitor software is used to receive and plot the parameters measured by the radiosonde and track the GPS data. Of course, this program is very nice and complete, but it is shareware, costs 25€ and runs only in Windows. I wanted to try if it is possible to track the GPS data in Linux using free software.

Continue reading "Receiving the Vaisala RS92-SGP radiosonde launched from Madrid-Barajas"

Concurso Nacional V-UHF

Today I've hiked up with my father to Siete Picos, SOTA summit EA1/SG-005 (2138m), to participate in this month's national V-UHF contest. We arrived and set up around 07:30UTC and worked until 11:30UTC, where activity became low, as most possible contacts were already done and people started to leave in order to prepare lunch. The equipment was a Yaesu FT-817ND and an Arrow yagi antenna (3 elements in 144MHz and 7 elements in 432MHz).

Below is the map of stations worked. My position is in red, stations worked both in 144MHz and 432MHz are in green and stations worked only in 144MHz are in blue. The black station is the odd one that I could only work in 432MHz. This can happen if you catch them first in 432MHz, then a big mess with several stations arises and you're unable to tell them to change to 144MHz to make the contact and decide that you'll catch them in 144MHz later, but you don't manage to find them later.

Continue reading "Concurso Nacional V-UHF"

Concurso Atlántico V-UHF

Today, I've participated in this month's national V-UHF from Cerro de San Pedro, SOTA summit EA4/MD-020 (1425m). I arrived the summit a bit before 10:00UTC and worked until the end of the contest (14:00UTC). The equipment was the usual: a Yaesu FT-817ND and an Arrow satellite yagi antenna (3 elements in 144MHz and 7 elements in 432MHz).

Find below the map of stations worked. My location is in red, stations worked both in 144MHz and 432MHz are in green and stations worked only in 144MHz are in blue.

Continue reading "Concurso Atlántico V-UHF"

Concurso Sant-Sadurní V-UHF

Last Sunday, I hiked up Cerro de San Pedro, SOTA summit EA4/MD-020 (1425m) to work in this month's national V-UHF contest. I was on the summit for 4 hours, from 7:00UTC to 11:00UTC, and I managed to work quite a few stations. As always, I used my portable QRP station consisting of a Yaesu FT-817ND and an Arrow satellite yagi antenna (3 elements in 144MHz and 7 elements in 432MHz).

In the map of stations worked, my position is in red, stations worked both in 144MHz and 432MHz are in green and stations worked only in 144MHz are in blue.

Continue reading "Concurso Sant-Sadurní V-UHF"

Concurso Segovia V-UHF

This weekend has being very rainy, so I haven't been able to participate in the national V-UHF contest with my usual portable setup. Instead, I have driven to the countryside just outside town and used the mobile antenna on my car to work in the contest from inside the car. This antenna is a 50cm vertical whip which is magnetically mounted on the roof of the car. Of course, due to the low gain and polarization mismatch, I am only able to work some local contacts with this antenna. In this way, I have been able to have a couple hours of fun this morning without getting wet.

As always, the map of stations worked below. My position is in red. Stations in blue where worked only in 144MHz. Stations in green where worked both in 144MHz and 432MHz.

Continue reading "Concurso Segovia V-UHF"

First signals from AAUSAT-4

Today I woke up early to receive the signals from AAUSAT-4 as it passed over Spain for the first time. This satellite was launched from Kourou yesterday at 21:02UTC into a Sun-synchronous orbit. The main payload for the launch was Sentinel-1B, a 5GHz Synthetic Aperture Radar satellite from the Copernicus project of the ESA. The remaining satellites that were launched by the Soyuz rocket were Microscope, from the French CNES, designed to test Einstein's equivalence principle and the three cubesats in the Fly You Satellite! program: OUFTI-1, from the University of Liège, which carries a D-STAR amateur radio transponder, e-st@r-II, from the University of Torino, and AAUSAT-4, from the University of Aalborg, which carries an AIS receiver. Since the launch was into a polar orbit, the first pass of the Fly Your Satellite! cubesats over Spain was at 05:42UTC today.

Continue reading "First signals from AAUSAT-4"

Concurso Costa del Sol V-UHF 2016

Yesterday, my father and I hiked to Cerro de San Pedro, SOTA summit EA4/MD-020 (1425m), to work QRP in this month's national V-UHF contest: Concurso Costa del Sol. Since the forecast for Sunday was rainy, I decided to go up on Saturday's afternoon. The summit is a short hike from a nearby road. We arrived to the summit around 14:25UTC, so I could work in the contest for a bit more than two hours until we started packing at 17:00UTC before it got too dark.

Activity seemed a little low, although this is not surprising, given that the national RTTY contest was also running at the same time. I also get the impression that there is more activity on Sunday mornings. Nevertheless, my results have been better than in March's contest. I did fewer QSOs, but got more points and worked more DX. In fact, I could work almost everybody I heard. In the map below, as always, my location is marked in red, the stations in blue are those worked only in 144MHz and the ones in green where worked both in 144MHz and 432MHz.

Continue reading "Concurso Costa del Sol V-UHF 2016"

Concurso Combinado V-UHF 2016

This weekend, being the first weekend in March, marks the start of the Spanish V-UHF contest season for this year. In previous years, I've been operating casually in some of these contests as a portable station. Sometimes I've worked on the countryside just outside my town, Tres Cantos, and on other occasions I've being enjoying the contest from a summit while doing a SOTA activation. My plan for this year is to participate in all (or almost all) of the contests and try to work from a summit as many times as I can. I pretend to work QRP (5 Watts) always and enter the 6-hour category, which allows working for a maximum of 6 consecutive hours.

Today, I've worked in the Concurso Combinado V-UHF. The weather forecast was too windy and cold to stay for several hours on a summit, so I decided to work from the countryside near town. I've worked this morning from 09:00UTC to 12:00UTC more or less. The equipment was, as usual, an FT-817ND and an Arrow satellite yagi antenna (3 elements on 144MHz and 7 elements on 432MHz). See below for a map of the stations worked. My position is marked in red, the stations worked in 144MHz only are marked in blue and the stations worked in both 144MHz and 432MHz are marked in green.

Continue reading "Concurso Combinado V-UHF 2016"

Building the GALI-39 amplifier kit from Minikits

The GALI-39 is a DC-7GHz MMIC amplifier from Minicircuits. This device has a gain around 20dB and a NF of about 2.4dB. The nice thing about MMICs is that their input and output impedances are matched to 50Ω, so it's quite easy to work with them. Minicircuits makes many MMIC amplifiers suiting different needs, but unfortunately their products are not so easy to get in small quantities.

Minikits.com.au is an Australian store that sells Minicircuits parts in small quantities as well as many interesting RF kits. I needed some RF amplifier having a known NF to do some signal level calibrations, so I ended up ordering the GALI-39 amplifier kit from Minikits. This kit includes just the GALI-39, a PCB and the handful of SMD components you need to bias the amplifier. At 22AUD, the price of the kit is about right and buying the kit instead of just the GALI-39 saves me to do the shopping for the assorted SMD components and using the PCB instead of botching some circuit is always nice, because the PCB uses microstrip transmission line (but the substrate is regular FR-4). Here I have a look at what is included in the kit (I've been unable to find a complete list on Minikit's web).

Continue reading "Building the GALI-39 amplifier kit from Minikits"