Charlas en IberRadio

English summary: Slides and recordings for the two talks I gave yesterday in IberRadio. One of the is about gr-satellites and the other one is about Linrad. All the material are in Spanish.

Ayer estuve en la feria IberRadio, en Ávila, dando dos charlas: una sobre gr-satellites y la otra sobre Linrad. Las diapositivas en PDF de las charlas se pueden descargar aquí:

He grabado las charlas usando mi cámara. El enfoque y la exposición no son muy buenos, pero he editado el vídeo incluyendo encima las imágenes de las diapositivas, lo que facilita seguir el vídeo de la charla. Por contra, las demostraciones en directo en la charla de Linrad se ven un poco mal.

Actualización: David EA1FAQ también hizo grabaciones de las charlas. En sus grabaciones se ve mejor el proyector, por lo que las demostraciones en directo durante la charla de Linrad se siguen mejor. Incluyo links más abajo.

Grabaciones con diapositivas por EA4GPZ

Grabaciones por EA1FAQ

Waterfalls from the EAPSK63 contest

Last weekend, I recorded the full EAPSK63 contest in the 40m band with the goal of monitoring IMD levels. I made a 48kHz IQ recording spanning the full 24 contest hours (from 16:00 UTC on Saturday to 16:00 UTC on Sunday). This week I've been playing with making waterfall plots from the recording. These are very interesting, showing patterns in propagation and contest activity. Here I show some of the waterfalls I've obtained, together with the Python code used to compute them.

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Monitoring IMD levels in the EAPSK63 contest

This weekend I have recorded the full EAPSK63 Spanish PSK63 contest in the 40m band with the goal of playing back the recording later and reporting the stations showing excessively high IMD levels. In PSK contests, it is usual to see terribly distorted signals, which are the result of reckless operating techniques and stations which are setup inadequately. Contest rules don't help much, as they are usually too weak to prevent distorted signals from interfering other participants. Amateurs should take care and strive to produce a signal as clean as possible. For instance, in the US, Part 97 101 a) states that "each amateur station must be operated in accordance with good engineering and good amateur practice". Here I describe the signal processing done in this study and list a "hall of shame" of the worst stations I have spotted in my recording. I will notify by email the contest manager and all the stations in this list with the hope that the situation improves in the future.

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Concurso QSL V-UHF

Today I've hiked to Cerro de San Pedro, SOTA summit EA4/MD-020 (1425m), to work in the last national V-UHF contest of the year: concurso QSL. This contest is a bit particular, because it coincides with the IARU-R1 UHF & up contest, so the contacts in the UHF & up bands count for both contests. As always, I'm participating in the 6 hours category with my QRP station: a FT-817ND with 5W and a 3 element yagi on 144MHz and 7 element yagi on 432MHz (the Arrow satellite yagi).

I arrived at the summit at 8:00UTC and worked until the end of the contest, at 14:00UTC, so I could enjoy almost 6 full hours of operation. As expected, after 12:00UTC there where few people left in the contest, as almost everybody had gone for lunch. The map of stations worked is below. Stations in green where worked both on 144MHz and 432, stations in blue where worked only on 144MHz and my operating position is marked in red.

Participation has been perhaps a bit low and propagation was not so good at times, but overall I'm happy with my results, which compare well with other contests this year. I missed some usual stations from the zones EA3 and EA5. I think that propagation to these zones was only open briefly during the contest.

IARU R1 145MHz contest

Today I hiked with all the family to La Najarra, SOTA summit EA4/MD-013 (2122m), to participate in the IARU Region 1 145MHz contest. Unfortunately, for some weird reason very few stations in Spain participate in this contest. My plan was to make a combined contest activity and SOTA activation, making QSOs with whoever was working SSB in the contest, but spending most of the time calling in FM. This gives me the opportunity to contact many more stations, because not many hams have a VHF yagi and SSB radio, but many have a VHF vertical and FM radio. It also gives these local hams the possibility to work a SOTA summit (most SOTA activity is in HF here) and work some DX with a quite basic FM station (100km or more are easy to achieve).

I worked from around 9:30UTC to 11:30UTC. The station was, as usual, an FT-817ND with 5W and an Arrow satellite yagi (3 elements).

I've put in the contest log all stations that were able to give me their locator (many hams that work only FM have no clue about what locators are). This is OK with the contest rules. The other stations went only to the SOTA log. Below, you can find the map of contest contacts. I made a total of 17 contacts, but, of course, I can't put on the map the stations that didn't know their locator.

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.

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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.

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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.

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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.

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