Tagged: funcube

SDR# and other Hobbyist Ham Radio Software Spotted in Netflix TV Show Yakamoz S-245

Thanks to all who submitted, we recently received some interesting tip offs about the Netflix TV Show Yakamoz S-245 featuring a scene with various hobbyist SDR and ham radio programs clearly visible. Yakamoz S-245 is a show about a submarine research mission, and the scene appears to depict military intelligence specialists using the programs.

In the scene we've spotted SDR#, MMSSTV, FUNcube dashboard, SATPC-32, and Orbitron. For those interested, the scene is in episode one time 11:20 - 12:00. 

Monitoring FT8, JT65, JT9 on Multiple Bands with Low Cost Single Board PCs

Thank you to Michael (dg0opk) who wrote in and wanted to share details of his full SDR monitoring system for weak signal HF modes. His setup consists of nine ARM mini PCs (such as Banana Pi's, Raspberry Pi's, and Odroid's), several SDRs including multiple RTL-SDR's, an Airspy Mini, FunCube Dongle and SDR-IQ, as well as some filters and a wideband amp. For software he uses Linrad or GQRX as the receiver, and WSJTx or JTDX as the decoding software, all running on Linux.

Michael also notes that his Bananapi FT8, JT65 and JT9 SDR monitor has been up and stably running continuously for half a year now. Bananapi's are lower cost alternatives to the well known Raspberry Pi single board computers, so it's good to note that a permanent weak signal monitoring system can be set up on a very low budget. Presumably even cheaper Orange Pi's would also work well.

With his setup he is able to continuously monitor FT8, JT65 and JT9 on multiple bands simultaneously without needing to tie up more expensive ham radios. His results can be seen on PSKReporter. A video of his RTL-SDR Raspberry Pi 3 decoding FT8, JT65 and JT9 can be found here.

Weak Signal Receiver Setup
dg0opk's weak signal receiver setup

Comparing the RTL-SDR, FunCube PRO Plus and SDRplay on Moon Bounce/EME Reception

Moon Bounce or “Earth Moon Earth” (EME) is an amateur radio activity where people attempt to transmit a signal towards to the moon, and listen to the reflected signal. In some cases a separate transmitter is not needed, as an already powerful constant transmitter like the GRAVES radar in France can be used.

Over on his YouTube channel user cqpy2rn has uploaded a video showing his moon bounce reception of the GRAVES radar using an eleven element yagi antenna. He compares the reception with an RTL-SDR, FunCube PRO Plus and SDRplay. He writes:

+++ Nooelec model NESDR Smart (RTL-SDR) +++
GOODs: Price $20, frequency stability 0.5ppm tcxo, aluminum case, firm sma antenna connector, better dynamic range than regular-cheaper RTL dongles. Easy gain adjustment.
BADs: No pass filters, freq coverage from 24MHz to 1.7GHz, poor dynamic range (moderate de-sense with near strong signals)

+++ FunCube PRO PLUS – FCDPP +++
GOODs: freq coverage from 150KHz to 2GHz, pass saw filters, frequency stable 0.5ppm tcxo, easy gain adjustment, acceptable dynamic range.
BADs: Plastic case, fragile sma connector, just 192KHz wide spectrum view, price $160.

+++ SDRPlay +++
GOODs: Frequecy coverage from 10KHz to 2GHz, firm SMA connector, pass saw filters, up to 8MHz wide spectrum view, acceptable dynamic range.
BADs: Plastic case, legacy printer USB connector, frequency drift during warm up, difficult gain adjustment

CONCLUSION: In essence all these have the same “DNA”, they were made from digital TV tuner chips, comparisons produce very similar RX practical results, the RTL suffers due the lack of internal filtering which can be a little remediated adjusting the gain carefully through your SDR software or adding external filters. FCDPP and SDRPlay are vey similar, although the freq drift for SDRPlay is a bit annoying to me.

Nooelec RTL vs. FunCube PRO Plus vs. SDRPlay (VHF 143MHz graves via EME test)

How to Receive the Funcube Satellite with an RTL-SDR

Over on the Hamspirit.de blog author Jan as written a post explaining how to receive the FUNcube satellite with an RTL-SDR dongle (note in German, use Google translate). The FUNcube is a CubeSat (a low cost miniature 10 cm cube sized satellite) which is intended mainly for educating young people about radio, space, physics and electronics, but has also piqued the interest of amateur radio hobbyists.

Jan first writes how the Funcube Dongle was originally invented as a low cost means of receiving the FUNcube satellite, but now there are the even lower cost RTL-SDR dongles. Jan’s post then goes over how to receive the FUNcube at a frequency of 145.935 MHz using software such as SDR-Radio or SDR# and how to decode the telemetry data using the FUNcube dashboard. He also explains a bit about the FUNcubes operating modes which change the satellites transmission strength depending whether or not its solar panels are in sunlight or not.

Funcube Telemetry Dashboard
Funcube Telemetry Dashboard

Modifying a Laptop by Embedding an RTL-SDR and FunCube Dongle

Blogger “French Fry Cattaneo” wanted a portable laptop with built in SDR capability. To achieve this he opened up his Panasonic ToughBook CF-30 laptop and embedded an RTL-SDR FubCube dongle into the laptop using the space left by unused expansion ports.

Cattaneo connected the two SDRs to a small hub and soldered the usb hub connections directly onto a laptop USB port. He also installed an external SMA connector for the RTL-SDR and connected the FunCube’s antenna port to a cellular antenna that was built into the laptop.

He notes that there could be RF interference issues from the laptop, but has so far had no trouble receiving the strong signals he is interested in.

Laptop with built in RTL-SDR and FunCube Dongles
Laptop with built in RTL-SDR and FunCube Dongles

Using the RTL-SDR to listen to the Funcube Satellite

Recently, the FUNcube-1 satellite was successfully launched. The FUNcube is a CubeSat (a low cost miniature 10cm cube sized satellite) which is intended mainly for educating young people about radio, space, physics and electronics, but has also piqued the interest of amateur radio hobbyists.

Amateur radio hobbyist N4JTC’s has shared on his blog his experiences with receiving the FUNcube-1’s telemetry using his RTL-SDR dongle. By using the RTL-SDR to receive the telemetry beacon as the satellite passes overhead, he was able to use the FUNcube Dashboard software to record and decode and view the satellites telemetry data.

Receiving the FUNcube-1 Satellite
Receiving the FUNcube-1 Satellite

Tutorial: HF Decoding Tour with the FUNcube Dongle Pro+

On the FUNcube Dongle blog/store amateur radio enthusiast DK80K (a.k.a Nils) has sent in a link to a 16 page pdf file showing a comprehensive tour on the FUNcube Dongle Pro+’s capabilities on the HF spectrum.

He gives an overview of many digital ham and HF utility modes including DRM, WSPR, RTTY, Olivia, MFSK16, PSK31, Pactor, Packet, Hellschreiben, ROS, SSTV, HF ACARS, SSB, CW, DSC/GMDSS, SITOR-A/B, Globe Wireless, Time Signals, ALE, Baudot, FAX and Stanag 4285.

The FUNcube is a software defined radio similar to the RTL-SDR, but with better sensitivity and noise performance, but at a higher price (around $200 USD). These modes can also be received with the RTL-SDR and an upconverter such as the Nooelec Ham-It-Up upconverter.

Download his pdf here (Mirror)

RTL-SDR for Budget Radio Astronomy

With the right additional hardware, the RTL-SDR software defined radio can be used as a super cheap radio telescope for radio astronomy experiments such as Hydrogen line detection, meteor scatter and Pulsar observing.

Hydrogen Line

Marcus Leech of Science Radio Laboratories, Inc has released a tutorial document titled “A Budget-Conscious Radio Telescope for 21cm“, (doc version) (pdf here) where he shows:

Two slightly-different designs for a simple, small, effective, radio telescope capable of observing the Sun, and the galactic plane in both continuum and spectral modes, easily able to show the hydrogen line in various parts of the galactic plane.

He uses the RTL-SDR as the receiving radio with an LNA (low noise amplifier) and a couple of line amps, a 93cm x 85cm offset satellite dish (potential dish for sale here, and here), and GNU Radio with the simple_ra application. In his results he was able to observe the spectrum of the Galactic Plane, and the Hydrogen Line. Some more information about this project can be found on this Reddit thread.

Here is a link to an interesting gif Marcus made with his RTL-SDR, showing a timelapse of recorded hydrogen emissions over 24 hours. Reddit user patchvonbraun (a.k.a Marcus Leech) writes on this thread an explanation of what is going on in the gif.

Interstellar space is “full” of neutral hydrogen, which occasionally emits at photon at a wavelength of 21cm–1420.4058Mhz.

If you setup a small dish antenna, and point at a fixed declination in the sky, as that part of the sky moves through your beam, you can see the change in spectral signature as different regions, with different doppler velocities move through your beam.

This GIF animation shows 24 hours of those observations packed into a few 10s of seconds.

 Marcus’ setup is shown below.

RTL-SDR Radio Telescope Setup

And here is just one of his many resulting graphs shown in the document showing the Hydrogen line.

RTL-SDR Radio Telescope Hydrogen Line

A similar radio astronomy project has previously been done with the Funcube. More information about that project can be found in this pdf file. In that project they used the Funcube, a 3 meter satellite dish and the Radio Eyes software.

However, in this Reddit post patchvonbraun explains that the Funcube’s much smaller bandwidth is problematic, and so the rtl-sdr may actually be better suited for radio astronomy.

This image is from the Funcube project document.

Funcube Radio Telescope Project

Another related project is the Itty Bitty Telescope (IBT), which does not use SDR, but may be of interest.

Meteor Scatter

Meteor scatter works by receiving a distant but powerful transmitter via reflections off the trails of ionized air that meteors leave behind when they enter the atmosphere. Normally the transmitter would be too far away to receive, but if its able to bounce off the ionized trail in the sky it can reach far over the horizon to your receiver. Typically powerful broadcast FM radio stations, analog TV, and radar signals at around 140 MHz are used. Some amateur radio enthusiasts also use this phenomena as a long range VHF communications tool with their own transmitted signals. See the website www.livemeteors.com for a livestream of a permanently set up RTL-SDR meteor detector.

In Europe typically the Graves radar station can be used for meteor scatter experiments. Graves is a space radar based in France which is designed to track spacecraft and orbital debris. If you are in Europe you can also make use of the Graves radar simply by tuning to its frequency of 143.050 MHz and listening for reflections of its signal bouncing off things like meteors, planes and spacecraft. Since Graves points its signal upwards, it’s unlikely that you’ll directly receive the signal straight from the antenna, instead you’ll only see the reflections from objects.

In other countries old and distant analogue TV stations can be used or FM transmitters can also be used.

To set meteor scatter up, simply use an outdoor antenna to tune to a distant transmitter. It should be far enough away so that you can not be receive the transmitter directly, or the signal should be weak. If you detect a meteor the signal will briefly show up strongly at your receiver. Performance can be enhanced by using a directional antenna like a Yagi to point upwards at the sky in the direction of the transmitter.

We have several post about meteor scatter available on the blog here. Read through them to get a better understanding of the ways in which it can be monitored. You may also be interested in Marcus Leech’s tutorial where he uses the RTL-SDR to detect forward meteor scatter. (doc here) (pdf here)

Pulsar Observing

A pulsar is a rotating neutron star that emits a beam of electromagnetic radiation. If this beam points towards the earth, it can then be observed with a large dish antenna and a radio, like the RTL-SDR. 

Pulsars create weakly detectable noise bursts across a wide frequency range. They create these noise bursts at precise intervals (milliseconds to seconds depending on the pulsar), so they can be detected from within the natural noise by performing some mathematical analysis on the data. Typically a few hours of data needs to be received to be able to analyze it, with more time needed for smaller dishes.

One problem is that pulsar signals can suffer from ‘dispersion’ due to many light years of travel through the interstellar medium. This simply means that higher frequencies of the noise burst tend to arrive before the lower frequencies. Mathematical de-dispersion techniques can be used to eliminate this problem enabling one to take advantage of wideband receivers like the RTL-SDR and other SDRs. The more bandwidth collected and de-dispersed, the smaller the dish required for detection.

Pulsar detection requires some pretty large antennas, and a good understanding of the techniques and math required for data processing so it is not for the beginner. See the previous Pulsar posts on this blog for more information.


If you enjoyed this tutorial you may like our ebook available on Amazon.

The Hobbyist’s Guide to the RTL-SDR: Really Cheap Software Defined radio.