Last month we released our new L-band active patch antenna for sale, and not too long after we had a review from Frugal Radio praising it. We now have two more YouTube reviews available to share.
The first is from Tech Minds who does a teardown and demonstrates it receiving and decoding the Inmarsat STD-C NCS channel, receiving and decoding GPS and receiving Iridium signals. The second is from Mike Ladd from SDRplay, who tests it with an SDRplay RSP1A software defined radio. He shows that the patch works perfectly with an RSP1A, and demonstrates it receiving and decoding STD-C while mounted on the dash of his vehicle.
L-Band Patch Stock Availability Note: We note that we are already close to selling out of the first batch of these units as they sold much faster than expected! New sales of this patch are currently backordered but we expect to have a few more units from this first batch available by the end of next week. Also the freighter with Amazon USA stock should be arriving any day now, but it could still take a few weeks to get through the port and reach the warehouse due to the current port delays.
The second production batch of this antenna might still be a while away due to the electronic component shortage crisis occurring now, so if you were thinking about picking one up, please order ASAP.
RTL-SDR BLOG L-BAND Patch Antenna Version 2 - Inmarsat - Iridium - GPS
Back in early and mid March we posted about how several amateur radio hobbyists worked together to receive and figure out how to decode text telemetry as well as live video from SpaceX Falcon 9 rockets using low cost antennas and SDRs.
Unfortunately the fun has abruptly come to an end, with listeners discovering that the latest launch is now fully encrypted. Given the fact that the data stream was undiscovered and likely unencrypted for the last decade, it seems reasonable to assume that SpaceX added encryption in response to media publicity from the decoding discovery. There is also speculation that it may be due to NOAA space camera laws which caused livestream censorship back in 2018.
Over on YouTube Rob from Frugal Radio has uploaded a video reviewing our new L-Band Patch antenna which we released for sale late last month. The patch is currently on a release sale for US$44.95 including free standard airmail shipping to most countries. We will be ending the sale this Wednesday at which point the price will go to US$49.95, still with free standard airmail shipping to most countries. The patch can be purchased from our web store at www.rtl-sdr.com/store.
In the video Rob demonstrates the patch receiving Inmarsat signals strongly, and decodes a few AERO signals using JAERO. He shows that the patch works on any RTL-SDR with bias tee capability as well as an Airspy Mini. Lastly he compares the unit against the SDR-Kits patch.
We note that we are also supplying a kit for a giveaway to Frugal Radio subscribers that we will announce in an upcoming video coming out a few days time.
RTL-SDR updated L-band patch antenna review - perfect for your SDR radio!
UPDATE: Giveaway information now available in the latest video below.
Satellites can stay in orbit for years after their decommissioning date. Although they are turned off, often after many years they can turn on again as the battery chemicals begin to break down, eventually allowing electricity directly to the satellite systems whenever the solar panels are in light. We've seen this phenomenon occur with various decommissioned satellites.
The NOAA 2 spacecraft is tumbling with a period of about 88.6s. The on/off duty cycle is asymmetrical with it on for about ~28s and off for ~61s. The plot below shows the ragged nature of this almost 50 year old emitter. pic.twitter.com/iWV62eV2si
Next over on his blog Derek OK9SGC was able to confirm reception of the signal, make a recording, and then with the help of @Xerbo10 discovered that you can actually receive an image from it. However as is to be expected the camera is not actually operational and all you get is a few grey lines indicating voltage calibration and sync telemetry.
It's unknown how long the satellite will stay undead, but if you manage to receive it let us know in the comments.
After further investigation it looks like FM encoded FM (unlike FM encoded AM used by APT), after that you can a brightness calibration ramp! pic.twitter.com/iZ6dju10hG
Over on his YouTube channel saveitforparts has uploaded a video showing how he was able to modify and old DirectTV satellite dish found in the dumpster with cardboard and foil in order to receive images from the GOES-16 geostationary weather satellite.
I wanted to download images from the GOES-16 weather satellite, but didn't have a big enough satellite dish. So I made one out of an old TV dish, cardboard, and aluminum tape! Amazingly this actually works, and I was able to pull live pictures of the earth off the satellite in geostationary orbit! The cardboard won't last long-term, so I'm looking for an antique C-band dish that I can set up as a more permanent solution. However, for a cheap and expedient ground station, this worked pretty well!
Satellite Ground Station With Trash, Cardboard, and Foil Tape!
Back in April 2020 we first heard about the launch of SMOG-P which was the first functioning 1-PocketQube satellite, and was designed to measure electromagnetic pollution (electrosmog) from space. SMOG-1 is the successor to SMOG-P and it carries a similar mission to measure electromagnetic pollution generated by human activity in space around the Earth. Interestingly it also carries a magnetically lossy material under it's solar panels which is to act as a brake, reducing the 18-25 Orbital lifespan, thus reducing space trash after the primary mission is complete.
According to the receive and decoding instructions provided by Levente Dudas, SMOG-1 can be received with a simple satellite antennas, such as a handheld Yagi, Turnstile, Dipole or quadrifilar-helix antenna. The telemetry frequency is 437.345 MHz with callsign HA5BME. For the radio an RTL-SDR connected to a Raspberry Pi can be used, and the telemetry decoding software can be found on GitLab.
SMOG-1 can be tracked here, although Zoltan mentions that the TLEs may not yet be accurate for several more days or weeks, as was seen with the launch of SMOG-P as well. The reason is that it is difficult for the NORAD radars to see these tiny PockQube satellites which is required for TLE generation.
We have just received stock of our new L-band active patch antenna design. The antenna is designed for receiving L-band satellites such as Inmarsat, Iridium, GPS and other satellites that transmit between 1525 - 1660 MHz (please note that you cannot use it for weak signals that require a dish like HRPT or GOES). The antenna comes as a set with a large suction cup, 3M RG174 extension cable and bendable tripod to help with mounting. Preorder pricing is US$44.95 including free worldwide shipping to most countries shipped from our warehouse in Shanghai. At the end of this week (extended for one more week!) pricing will rise to the standard cost of US$49.95. Amazon stock will require time, and won't be in for at least 6+ weeks.
Like our previous patch design, this is an actively amplified antenna as it contains a built in low noise amplifier which takes power from a 3.3 - 5V bias tee. This power is available from from our RTL-SDR Blog V3 dongles, and other SDRs like the Airspy, HackRF and SDRplay. It also has a built in SAW filter after the LNA to help reduce terrestrial interference.
Compared to the previous design the new patch is larger (175 x 175 mm) with higher gain and wider radiation pattern. This allows for much easier pointing of the antenna and for much stronger signals. The upper frequency range has also been extended to 1660 MHz from 1625 MHz. The included suction cup is also much larger allowing for the patch to point at more angles without being restricted by the window. The patch is enclosed within a new weatherproof plastic enclosure.
The screenshots below show the patch receiving various signals like AERO, STD-C and Iridium
The antenna should be used with one meter or more of coax cable. It may perform poorly if the RTL-SDR is placed right at the antenna due to interference. If you want to run very long cable, then low loss coax should be used.
The patch can be used flat, or angled towards the satellite. Angling it towards the satellite will yield significantly higher gain.
If you have very strong cell phone interference in your area, try using the patch a bit lower to the ground, and use buildings to block the interfering signal.
Last week we posted about how several users on Reddit & Twitter worked together to receive and decode text telemetry from the SpaceX Falcon 9 rocket launch using a HackRF, 1.2m dish with custom 2232.2 MHz feed and GNU Radio. In that thread it was hinted that the text telemetry was only a small portion of data contained in the entire signal. It turns out that the remaining data is the SpaceX engineering video feed which is often shown in the official live coverage streams.
So today at 10:21UTC i got my own recording of Falcon9 video feed downlink on S band 2272.5MHz and with u/Aang253's software SatDump i could easily decode it from the recording straight down to mxf, avi or mp4 video file! Even with very simple recieving setup!
Setup used for receiving was simple wifi grid mesh dish antenna (100x60cm) on a tripod with old MMDS TV downconvertor and Airspy MINI. here is a photo of the setup few minutes before launch But of course its doable without convertor with SDR such as HackRF , two SPF5189Z LNAs and same antenna or even TV dish with DIY S band feed!
Here is the decoded video feed i got today from S band transponder on 2272.5MHz from second stage of #SpaceX#Falcon9 rocket as it was passing above EUrope! Thanks a lot to @aang254 for the decoder software and @r2x0t for the extensive RE work he did on the downlink! Good work! pic.twitter.com/IgEESBA9A1
It's extremely interesting that we can see views of the liquid oxygen floating around inside the stage two tank which is not shown during the official live streams.
As a bonus, this story was also covered by the very popular space YouTuber Scott Manley who has put out a great video popularizing the discovery and touching on a few interesting points such as how SpaceX may be legally required to encrypt these videos in the future (but hopefully not!).
How Amateur Radio Fans Decoded SpaceX's Telemetry & Engineering Video