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Changes to the QO-100 NB transponder settings

Yesterday, AMSAT-DL announced that the narrowband transponder of QO-100 was under maintenance and that some changes to its settings would be made. This was also announced by the messages of the 400baud BPSK beacon. Not much information was given at first, but then they mentioned that the transponder gain was reduced by 6dB and a… Continue reading Changes to the QO-100 NB transponder settings

Decoding the QO-100 beacon with gr-satellites

On February 14, the Amateur transponders on Es’hail 2 (which now has the AMSAT designation QO-100) were inaugurated. Since then, two beacons are being transmitted by the groundstation in Doha (Qatar) through the narrowband transponder. These beacons mark the edges of the transponder. The lower beacon is CW, while the upper beacon is a 400baud… Continue reading Decoding the QO-100 beacon with gr-satellites

Measuring the Allan deviation of a GPSDO with an SDR

A few days ago I tried to measure the QO-100 NB transponder LO stability using my DF9NP 10MHz GPSDO. It turned out that my GPSDO was less stable than the LO, so my measurements showed nothing about the QO-100 LO. Carlos Cabezas EB4FBZ has been kind enough to lend me a Vectron MD-011 GPSDO, which… Continue reading Measuring the Allan deviation of a GPSDO with an SDR

Measuring the gain of a dish

Here I want to show a technique for measuring the gain of a dish that I first learned from an article by Christian Monstein about the Moon’s temperature at a wavelength of 2.77cm. The technique only uses power measurements from an observation of a radio source, at different angles from the boresight. Ideally, the radio… Continue reading Measuring the gain of a dish

An overview of IARU R1 interim meeting proposals

The IARU R1 interim meeting is being held in Vienna, Austria, on April 27 and 28. This post is an overview of the proposals that will be presented during this meeting, from the point of view of the usual topics that I treat in this blog. The proposals can be found in the conference documents.… Continue reading An overview of IARU R1 interim meeting proposals