Over on YouTube SignalsEverywhere has just uploaded his latest video about using a HackRF and Airspy R2/Mini to explore the signals coming out of an internet cable modem's coax cable. In the video he performs a wideband scan with his Airspy R2 and the SpectrumSpy software which shows not only his, but the downstream signals from other users in his neighborhood on the cable network too.
Next using his HackRF with Spectrum Analyzer and the hackrf_sweep fast sweeping software, he was able to determine the uplink portion of his cable modem. By running an internet speed test in the background he was also able to visualize the increased cable data activity on the spectrum waterfall display.
The Secret Signals Hiding In Your Cable Modem | SDR Used to Sniff Cable Internet Modem Coax
The Mission for Education and Multimedia Engagement Satellite (MEMESat-1) is planned to be the first meme broadcasting cube satellite ever created. If you aren't down with modern slang and are not familiar with the word "meme", that may be because although first coined in 1976, the modern definition was only added to the Webster-Miriam dictionary in 2015. In the traditional sense a meme is a cultural idea, behavior, style that people can't help but want to share because of how funny/amusing/interesting it is.
But in particular MEMESat-1 wants to broadcast from space the new type of meme definition, which is essentially funny or amusing images/GIFs that internet users and especially youth like to modify and share online through social media. Memes have become a major part of internet youth culture, so this could be an excellent way to speak the language of the next generation and get them interested in space, satellites, amateur radio and building satellite ground stations.
At the moment, the team hopes to launch the satellite by late 2021, and no later than Spring 2022. The satellite will be a cubesat with flash memory containing thousands of meme images that will be broadcast to Earth via a transmitter operating in the UHF 70cm radio band. Enthusiasts on the ground will be able to receive the meme images with a Yagi antenna and we anticipate that RTL-SDRs will be a commonly used receiver. The satellite will also contain an FM UHF/VHF repeater operating in the amateur radio band for ham radio use.
I went out and started a nonprofit organization, built a website, developed a meme-related anxiety disorder, and am now building a meme-beaming satellite with a group of undergrads at UGA and some industry sponsors. And it’s all for the sake of making a novel meme. We are now fundraising to launch MEMESat-1.
For those who are interested in reading about the trials and tribulations of a 22 year old man-child trying to send memes into space, I’ve included the longer story below.
For my whole university career, I was in search of different work opportunities and internships to see what felt the most fulfilling and to get some of those sweet sweet resume lines. I’ve interned at a plastic factory, the Air Force Research Labs, NASA JPL, and Ball Aerospace. They were all great places filled with awesome people and cool work, but I didn’t feel connected with my work in a way that fulfilled me. So, for the past 3 years me and my buddies have been joking around about building a satellite that beams down memes from space.
Enter MEMESat-1.
While I was working at JPL, me and some buddies got together to toy around with space start-up ideas. We joked more about MEMESat, and bought the memesat.com domain back in 2018. Due to timing and other life events the start-up idea kind of fell off. One of my pals is pursuing his Ph.D, and the other is working as a spacecraft engineer full-time. I on the other hand, still had 2.5 years of school left.
Work on the MEMESat concept slowly came to a halt by the end of 2018, but picked up again in Spring 2019 when I came up with the acronym the Mission for Education and Multimedia Engagement Satellite (MEMESat-1). I kept telling my classmates and friends about the project idea as a joke, but they thought I was being serious and told me to go for it. By May 2019 I had worked out a deal with some universities to use their space, and began building the website. Over that summer, my job left me some spare time, so I started ramping up the social media for MEMESat-1 by posting daily spacefacts to instagram. I also worked on some preliminary design studies to see if the mission would be feasible, and decided that it definitely was. I also spent the summer researching how to form a company, and what the best company structure would be.
In August 2019, I returned to school and began to work on forming a company. Some great profs at GT gave me the advice to start a nonprofit, so I searched for some pro bono legal advice on starting a nonprofit. I took some of the lawyer’s advice and found some willing Directors for the company, and filed to form a nonprofit corporation - called Let’s Go to Space, Inc.
Around that time, I posted to reddit and got a bunch of attention from you guys, so I figured I should work my hardest to make it happen. I spent months emailing every space related company I could find or even think of. I have much more respect now for people that lead telemarketing campaigns, because it is really hard to convince random people over the phone/email to give you large sums of money. Now, I am happily partnered with Ball Aerospace and sponsored by Blue Canyon Technologies. I’m also in talks with some launch providers about a free launch and some help launching my lesson plans/experiment kits to classrooms all over!
We have passed the point of no return and have nowhere to go but upwards. My parents are confused and slightly disappointed that their rocket scientist son has given up any sort of salary in an effort to appease his ‘internet friends’. God bless you magnificent weirdos for keeping me going. Ad Astra Per Memes.
Currently letsgo2space is fundraising and looking for $30,000 to fund the launch of MEMESAT-1. You can either donate any amount or submit a meme for their broadcast database for $1.69 via their website.
The Flex 6500 is a now discontinued (only refurb units available for US$2,600) transceiver SDR made for amateur radio use. Together with the optional Maestro control panel, it forms a fully standalone SDR based transceiver, with built in SDR software available on the Maestro's LCD screen. The system runs embedded Windows and is locked down to prevent the user from getting outside the Flex radio software.
However, a Norwegian University radio club found the Flex radio to be very inflexible as they could not connect the radio to their Universities WiFi system, which requires users to authenticate first via a web browser. What should be a simple task on any Windows system was unfortunately not supported by the radio software, and Flex radio themselves were unable to help.
Fortunately the students were able to hack the Windows filesystem via a backdoor found in the built in software, allowing them full access to the Windows desktop. The hack is fairly simple, consisting of gaining access to Notepad and thus the filesystem and command prompt via a "view source" right click menu on the web login interface. Once hacked, the students were able to install custom software like the N1MM+ contest logger, and WSJT-X for WSPR decoding. They were also able to connect a Bluetooth keyboard and mouse which was not supported by default.
Thank you to Benjamin Larsson for submitting news about a FC0013 tuner patch he's submitted for the Osmocom RTL-SDR driver code. FC0013 based RTL-SDRs have been relatively unpopular due to the reduced tuning range of only 22 - 1100 MHz, compared to the larger 24 - 1766 Mhz range provided by the R820T2 chip. However, they have been found in some cheaper units.
Benjamin's patch reportedly improves UHF performance above 862 MHz, and also seems to make ADS-B reception usable.
The patch was submitted to the Osmocom GitHub, however, this Git is not monitored as Osmocom have their own patch submission system via mailing list. But if you have a FC0013 dongle and want to try it, the entire change consists of only a single register value change which could easily be manually modified in the driver code before compilation.
Register change to improve UHF performance on FC0013 RTL-SDR dongles.
A ground penetrating radar (GPR) is a system that uses RF pulses between 10 to 2.6 GHz to image up to a few meters below the ground. A typical GPR system consists of a transmitting radio and antenna that generates the radar pulse aimed towards the ground, and a receiving radio that receives the reflected pulse.
GPR is typically used for detecting buried objects, determining transitions in ground material and detecting voids and cracks. For example, in construction it can be used to determine rebar locations in concrete, and in the military it can be used to detect non-metallic landmines and hidden underground areas.
Their system uses a step-frequency continuous waveform (SFCW) signal which scans over multiple frequencies over time, and the software was written in GNU Radio. In their tests they were able to detect a dry block of sand buried 6 cm below the ground, and a wet block 20 cm below.
Ground Penetrating Radar with two HackRF software defined radios.
Thank you to Arty Bishop for submitting news about his recently released Android App called Look4Sat. Look4Sat is a satellite tracker and pass predictor with a focus on amateur radio and weather satellites. The app is free, ad free, and open source on GitHub. Arty writes that he's programmed this as a learning exercise and notes:
I always wanted to have an offline and not bloated satellite tracker on my phone, as carrying the laptop at all times is kinda not too handy.
The app uses predict4java library under the hood and is written in Kotlin. The TLE files are from Celestrak and the transmitters info is from SatNOGS and once they are ownloaded the app doesn't need an internet connection.
The app creation and design is hugely inspired by Gpredict which is an absolutely brilliant piece of software. Thank you, Alexandru!
Obviously there is no ads and it's totally free. Hope more people find Look4Sat useful.
The features include:
Calculating satellite passes for up to one week (168 hours)
Calculating passes for the current or manually entered location
Showing the list of currently active and upcoming satellite passes
Showing the active pass progress, polar trajectory and transceivers info
Showing the satellite positional data, footprint and ground track on a map
Offline first: pass prediction is done offline. It's up to you to decide when to update the TLE file and the transceivers DB. (Updates once a week are recommended)
Thank you to Happysat who has shared with us a useful tutorial that explains how we can run Linux only SDR programs on a Windows 10 system using the Windows Subsystem For Linux (WSL) feature. WSL is a feature available on Windows 10 which is a Linux compatibility layer designed for running Linux binaries natively on Windows 10. This means that no Virtual Machine with shared resources is required, instead the full resources of your system are available.
Happysat writes:
Many people using Windows 10 now since Windows 7 is EOL, and WSL is part of the system kinda "free" so why not use it :)
Together with a X-Server and and Desktop like XFCE4, it can be great for running SDR applications in Linux thru rtl_tcp.
Very fast startup in seconds and not much packet loss thru tcp, quite alot linux sdr applications are working very good.
No allocating resources like a VM.
Sometimes better then Ubuntu on a VM.
Software tested: AX-25 Packet Radio, Dab Radio, DSD, Es-Hail Beacon Tracker, Sat Tracking with Gpredict and Gqrx, NOAA Reception WxToImg, Radiosonde Decoding, Shortwave Reception and some more tips and tricks about WSl and SDR.
The steps appear to be fairly simple. Just enable WSL in the Windows 10 Features panel, download a Linux distro built for WSL and run the .exe file. Then you'll have access to a Linux terminal where you can install a GUI desktop environment, the RTL-SDR drivers, and other Linux SDR programs. Happysats tutorial shows how to install and use various Linux programs via WSL.
It seems that the RTL-SDR cannot be directly accessed via the USB in WSL, however, by the workaround is to simply run rtl_tcp in your Windows environment, and connect to the local IP in the Linux environment. This means that only programs that accept rtl_tcp as an input, or demodulated audio from a program like GQRX can be used.
The Elad FDM-S3 is an upcoming high performance Hf speciality SDR that is expected to be released this year with a price of 949.90 € ($1040 USD). Over on the swling.com blog, and the Elad website we've seen some recently released information about the new specs.
Real Time I/Q Stream Bandwidth 192khz, 384KHz, 1536KHz, 12880KHz, 24576KHz
122.88 MSPS - 98.304 MSPS 16bit A/D converter
Clock synchronized to GNSS Global Navigation Satellite System or 10MHz Ext Ref
GNSS works with GPS, GLONASS, GALILEO, BEIDOU
Auxiliary USB used to monitor GPS status or for clock firmware updates
10MHz Clock reference Output
10MHz internal standart TCXO 100ppb referenced, optional 3ppb OCXO referenced
Compared to the FDM-S2 the FDM-S3 looks to have significantly increased bandwidth, meaning now that almost the entire HF spectrum could be monitored. ALso the optional built in downconverter would allow tuning up to 2 GHz, where it was previously limited to only 160 MHz on the FDM-S2. The new GNSS referenced clock and improved TCXO/OCXO is also going to mean significantly improved frequency stability.
