In his latest video, Matt from the TechMinds YouTube channel tests out an LHCP L-band helix feed designed for receiving Inmarsat satellites. Matt pairs the feed with an 85cm satellite dish, an L-band LNA, and an Airspy Mini.

The L-band helix feed comes from a small German engineering company called nolle.engineering. The feed is priced at 94.70 Euros (incl. VAT) (~$102 USD), plus shipping costs. It is a passive antenna so it needs to be combined with an LNA to be usable with a typical SDR.

In the video Matt shows that the reception with the LHCP helix + dish setup is better than expected. He also compares it to a previous test he did with a longer RHCP helix antenna also produced by nolle.engineering. The RHCP antenna is used to be used without a dish, however, as expected the SNR is less than the dish + small LHCP feed setup. Matt then shows some Inmarsat signals being decoded including STD-C and Aero voice.

Thank you to Robin OK9UWU who wanted to point out that the recently launched Russian Meteor M2-4 weather satellite has not failed. There have recently been rumors and videos being spread online claiming that the satellite has already failed as the LRPT and HRPT signals are currently offline.

However, the satellite is still in a testing phase and was only briefly transmitting images for a few days after launch. It is difficult to find official updates from Roskosmos, the Russian space agency, but Robin explains his thoughts on what is happening:

The satellite in question, Meteor-M N°2-4 did not fail. The reason for both the LRPT and HRPT transmitters to be off is that the primary instrument (MSU-MR) is currently undergoing a routine cleaning process to get the IR channels up and running correctly.

It's completely normal.

Other reason why it's off could be that they are testing the MeteoSAR instrument (2-4 is the first sat of this series to have this), hence why unnecessary radios might have been taken offline.

It's important to understand that these satellites are being used to do actual science, weather forecasting etc. They require careful testing and calibration which might take some time. It's not just for "cool imagery".

For example, it took months to get the VIIRS instrument running onboard of the NOAA-21 satellite.

Keep calm and nerdy!

The long awaited Russian Meteor M2-4 satellite was successfully launched on February 29, 2024 and is now in orbit, and is already transmitting images. If you are unfamiliar with them, Meteor M satellites are a class of Russian weather satellites that can be easily received with an RTL-SDR and appropriate satellite antenna. The easiest transmission to receive is around 137 MHz, and to receive this signal a simple V-Dipole or more advanced QFH antenna can be used. It also transmits in the L-band, and a small 60cm+ dish can be used to receive it with motorized or hand tracking.

The video below is an archived live stream of the launch.

Prior Meteor M class satellites have typically been plagued with various issues, but so far the launch and deployment of M2-4 appears to have gone very smoothly. Reports are that the signal strength is excellent (much better than M2-3 with it's suspected antenna deployment fault) and images have been received clearly on both VHF and L-band.

TLE's and SatDump have been updated to support Meteor M2-4, so if you want to receive the satellite be sure to update to the latest code on Github.

Over on X, Scott Tilley has posted an image he received recently on both bands.

Over on her YouTube channel IndiaRocketGirl has posted a video showing how she was able to build a satellite dish and feed to receive FengYun-2H S-VISSR signals and get beautiful full disk images of the earth.

In the US and other countries RTL-SDR fans will be familiar with how to receive images from the GOES geostationary weather satellite. However from countries like India most GOES satellites will not be visible. Fortunately there are alternative satellites like the Chinese FengYun-2H satellite which is visible from India. FengYun-2H is a geostationary satellite that sends down a S-VISSR signal containing full disk images of the earth.

In her video IndiaRocketGirl uses a 1.8 meter diameter antenna, a homemade helical feed, an LNA+filter and an RTL-SDR as her hardware. For software she uses SatDump.