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Scanning Ku band satellites with the FUNCube Dongle
I've recently installed my satellite dish and modified LNBF in my garden. This equipment will be used to receive Es'hail 2, the first geostationary satellite carrying an amateur radio transponder. Here...
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Arduino LED driver: prototype finished
Today I've finished my prototype of the Arduino LED driver. I had already soldered and tested all the components quite a while ago, but I ran out of connectors for the LED strings, so I had to wait for...
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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...
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Replacing the fuse F1002 in the FT-817ND
On last Saturday's V-UHF contest I observed reduced output power on the 70cm band in my FT-817ND. I spent the next day poking inside the radio with the oscilloscope trying to see where the problem was....
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Adjusting TX gain in the FT-817ND
If you've been following my latests posts, you'll know that during the last V-UHF contest I detected reduced output power on the 70cm band in my FT-817ND. The output power was only about 60% of the...
View ArticleOutputting the crystal oscillator directly in the Si5351
I'm using a OCXO/Si5351A kit as an external 27MHz reference for my LNBF-based 10GHz receiver. At first, I intended to use a buffer amplifier to take out directly the 27MHz cyrstal oscillator in the...
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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...
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Receiving Ku-band geostationary satellite beacons
After sorting out some problems with several connectors which caused huge phase noise in the external 27MHz reference, I have my 10GHz receiver up and running as it should. This station will be used to...
View ArticleA bunch of data from AAUSAT-4
Recently, I have published a Gnuradio AAUSAT-4 decoder in Github. It is based on software from the university team, but several parts have been rewritten completely. The current features of this...
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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...
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Decoding packets from GOMX-3: modulation and coding
Recently, Mike DK3WN pointed me to some decoder software for the satellite GOMX-3. This satellite is a 3U cubesat from GomSpace and transmits in the 70cm Amateur band. It has an ADS-B receiver on...
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Hailstorm in 12GHz
Yesterday, there was a big hailstorm in my town. During the storm, I rushed to the radio shack to see if this produced any effects in my Ku-band satellite receiver. This is a 95cm dish pointing to the...
View ArticleDecoding packets from GOMX-3: CSP packets
A few days ago, I talked about the modulation and coding used by the satellite GOMX-3. Here, I will look at the contents of the CSP packets transmitted by this satellite. Mike DK3WN has kindly sent me...
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Scramblers and their implementation in GNUradio
A scrambler is a function that is applied to a sequence of data before transmitting with the goal of making this data more "random-like". For instance, scrambling avoids long runs of the bits 0 or 1...
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LilacSat-2 subaudio telemetry
Yesterday, the FM repeater on the Amateur satellite LilacSat-2 was active. I've talked about LilacSat-2 before, but so far I hadn't made any recordings containing subaudio telemetry. While contacting...
View ArticleGOMX-3 data download
This weekend, Mike DK3WN caught GOMX-3 downloading a good amount of data. See his post here. This data consists mainly of the satellite retransmitting a lot of beacons that were generated during the...
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Trying to decode data from ÑuSat
Last Monday, a Chinese CZ-4B rocket launched the Chinese Earth observation satellite ZY-3 and the Argentinian satellites ÑuSat-1 and 2. These two satellites are the first of the Aleph-1 constellation...
View ArticleConcurso 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...
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KISS, HDLC, AX.25 and friends
A while ago, I uploaded my gr-kiss out-of-tree GNUradio module to Github. This is a set of blocks to handle KISS, HDLC and AX.25, which are the protocols used in amateur packet radio. There are several...
View ArticleUsing the CC1101 and Beaglebone black for IP traffic on 70cm
Lately, I have been experimenting with using a CC1101 chip together with a Beaglebone black single board ARM computer to transmit IP traffic over the 70cm Amateur band. There has been a similar project...
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