Showing the HF Interference Problem from Ethernet over Powerline Devices

Over on our YouTube channel we’ve uploaded a new video that shows how bad the interference from Ethernet over Power devices can be. Ethernet over Power, Powerline Networking, Powerline Communications or ‘HomePlug’ is a technology that allows you to use any of your household power outlets as an internet Ethernet port, completely eliminating the need for runs of Ethernet cabling. They are capable of high speeds and can be used anywhere in the house assuming the two plugs are on the same power circuit.

Unfortunately these devices tend to wipe out almost the entire HF spectrum for anyone listening nearby. As household powerline cables are not shielded for RF emissions they radiate in the HF spectrum quite heavily. In the video we demonstrate what the HF spectrum looks like with one of these devices used in the house. The particular device used was a TP-Link brand adapter, and a WellBrook Magnetic Loop antenna was used outdoors, with the null facing the house. An Airspy R2 with SpyVerter was used to view the spectrum.

The video shows that even when the network is idling there are several brief bursts of noise all over the spectrum. Then when a file is downloaded almost the entire spectrum is completely wiped out.

Interestingly from the video it appears that the amateur radio frequencies are actually carefully notched out and those frequencies remain relatively clean. Most manufacturers of these devices appear to have worked with the ARRL to please ham radio enthusiasts, but SWLers will likely be in trouble if any of these devices are used in your house or neighbors house.

Radio For Everyone New Posts: Line of Sight, Why USB Cable Quality Matters, Uputronics 1090 MHz Filtered Preamp Review

Over on his blog, author Akos has uploaded three new posts. The first post briefly explains visually what is meant by line of sight when it comes to radio signals. Essentially at UHF and higher frequencies the radio antenna needs to be able to ‘see’ the transmitter, meaning that any blockages such as trees, houses etc will block the signal.

In his second post Akos briefly explains why USB cable quality can matter when it comes to SDRs. He shows that some USB cables tend to pick up more interference than others. 

Finally in his third post Akos reviews the Uputronics 1090 MHz Filtered Preamp. Uputronics is a UK based company that sells various filtered LNA’s. Akos writes how he’s very impressed with the premium packaging, look and feel of the device and thickness of the metal case. In performance tests the preamp together with a V3 dongle with bias tee power clearly improves ADS-B position reports significantly. We note that we also have 1090 MHz filtered preamp from Uputronics (an older model), and can also highly recommend their products.

The Uputronics 1090 MHz Filtered Preamp reviewed on radioforeveryone.
The Uputronics 1090 MHz Filtered Preamp reviewed on

LimeSDR First Batch Shipping Now

The LimeSDR is a RX/TX capable SDR with a 100 kHz – 3.8 GHz frequency range, 12-bit ADC and 61.44 MHz bandwidth. Back in June 2016 they surpassed their $500k goal, raising over $800k on the crowdfunding site Crowdsupply. 

We predict that the LimeSDR will essentially be seen as an improved HackRF SDR, perfect for experimenting with and reverse engineering RF devices without the 8-bit ADC, poor sensitivity and half-duplex limitations of the HackRF. They also seem to be active in promoting software for the device, writing that they will eventually have an app store like marketplace for various LimeSDR apps.

Recently the LimeSDR has completed manufacturing of its first batch, and is now ready to ship to backers. A single LimeSDR right now costs $289 USD to preorder, and early bird supporters were able to snag one for $199 USD. They write:

Shipping Will Start in 24 Hours
The first batch of LimeSDRs and accessories has arrived safely at the Crowd Supply warehouse.

Address Changes Must Be Processed Now

Shipping of the first batch of orders will commence within the next 24 hours. If you need to change your address, you should do it now by logging into your Crowd Supply account and viewing your order.

When Will My Order Ship?

The only way to know to know with certainty if your order is shipping within the next few days is if you receive a shipping confirmation email from Crowd Supply. The logistics of shipping hundreds of varied orders around the world is complex enough that it’s not possible to tell you your exact place in line. For example, Crowd Supply will likely send several test shipments to different countries to gauge how well they get through customs and the timing of future shipments to those countries may be affected by the results.

When Will My Order Arrive?

Once your order has shipped, you will receive a shipping confirmation email with a tracking number. For orders destined for outside the US, it is not uncommon for the tracking information to cease being updated after it leaves the US, though for some countries (e.g., UK, Germany, Australia) the packages can continue to be tracked using your national postal website and the same tracking number. If there is a delay in delivering your package, you should check with your local customs office to make sure they are not holding it and waiting for you to pick it up.

We look forward to beginning to use our own LimeSDR and will post reviews when it arrives.

Some of the LimeSDR's ready for shipping.
Some of the LimeSDR’s ready for shipping.

Comparing the RSP1 and RSP2 on MF Non-Directional Beacon Reception

Over on our new YouTube channel we’ve uploaded a video comparing the SDRplay RSP1 and RSP2 on reception of Non-Directional Beacons at around 350 kHz. Both radios had their gains adjusted for the best possible SNR and reception. They were connected through a splitter to a Wellbrook Magnetic Loop antenna. The Hi-Z port on the RSP2 was used as Port A and Port B don’t have good reception below about 1 MHz.

In all tests the RSP2 appears to have the better SNR, a lower noise floor and thus better audio, though from the spectrum view the RSP1 seems to have a little less spurs.

Subscribe and keep an eye on our new YouTube channel as soon we’ll be uploading more RSP1 vs RSP2 comparisons, Airspy vs RSP2 comparisons and other SDR related videos as well.

Lowering the Noise Floor on HF with High Quality Coax

Bonito is a company that sells various products such as their own small active antennas. Some examples are the Bono-Whip (20kHz – 300 MHz), GigaActiv (9kHz – 3 GHz) and the MegaLoop (9kHz – 200 MHz). 

Over on their blog they’ve uploaded a post titled “why even good antennas need good coax cable”. The post explains why high quality heavy shielded coax cable may be required to receive HF signals in noisy environments. The author writes how even placing an antenna in a quiet area outdoors may not work if the coax is still run through an high interference environment, such as through a house.

Typically RG58 cable is most commonly used with HF antennas. However, the author noticed that when using RG58 he was still receiving FM stations, even though the antenna that he was using was a MegaLoop with a built in broadcast FM filter. After switching his RG58 cable to H155 coax, the FM station disappeared. H155 coax is low loss and designed for GHz level frequencies, so it has much better shielding from its tighter braid.

The images below also show the difference in noise floor the author saw after replacing all his RG58 with H155 coax. 


Reception with RG58 Coax


Reception with H155 Coax

WaveConverter: An Open Source RF Reverse Engineering Tool

During the Schmoocon 2017 conference presenter Paul Clark introduced a new open source Linux tool called WaveConverter which he’s been working on for reverse engineering RF signals. Paul writes:

WaveConverter is a tool that helps you extract digital data from RF transmissions that have been captured via Software Defined Radio (SDR). After the user defines the modulation parameters, framing and encoding, WaveConverter will process a stored I-Q file and extract the data from any transmissions that match this definition. Using programmable timing tolerances and glitch filters, WaveConverter is able to extract data from signals that would otherwise appear corrupted.

This software will make the process of reverse engineering signals easier and more error-proof. Because WaveConverter includes the ability to store and retrieve signal protocols (modulation + encoding parameters), we have been generating a database of protocols that we can quickly use to iteratively attack unknown signals.

This tool should be very useful for reverse engineering digital signals, such as those found in keyfobs, wireless doorbells, wireless temperature sensors and any other simple RF device. Simply use an SDR device like an RTL-SDR to capture a sample of the signal of interest and then open it up in WaveConverter to first easily analyze the signal and determine it’s properties, then to automatically demodulate any subsequent signal into a binary string. For more information the documentation can be found here (pdf).

WaveConverter seems to be quite similar in purpose to Inspectrum and DSpectrum which are two Linux tools that are also designed for reverse engineering digital signals.

WaveConverter Screenshot
WaveConverter Screenshot
[First seen on Hackaday]


Receiving GOES Weather Satellite Images with a Small Grid Antenna and an Airspy Mini

GOES is an L-band geosynchronous weather satellite service that can be received typically with a satellite dish. It produces very nice full disk images of the earth. In the past we’ve posted about Lucas Teske’s work in building a GOES receiving system from scratch (including the software decoder for Airspy and RTL-SDR receivers), devnullings post about receiving GOES and also this talk by @usa_satcom on decoding GOES and similar satellites.

Over on Twitter @usa_satcom has been tweeting about his experiments where he has been successfully receiving GOES L-Band weather satellite images with a small grid antenna and an Airspy Mini. In a Tweet he writes that the antenna is an $85 USD Hyperlink 1.9 GHz 22 dBi Grid Antenna made by L-com. A grid antenna may be more suitable for outdoor mounting for many people as they are typically lighter, smaller and more suitable for windy and snowy conditions. As the GOES satellite is in geosynchronous orbit, no tracking motor or tracking mount is required.

An Update on the PatronX Titus II

Back in September 2016 we posted about the PatronX Titus II portable software defined radio which appears to currently be on its way to beginning production. It is a portable Android tablet based SDR, which we speculate is using similar chips to the SDRplay RSP with its 100 kHz to 2 GHz tuning range. The price goal is set to be under $100 USD.

Currently it is available for ‘pre-order’ on the HFCC website, although what they call a pre-order is actually just an expression of interest, and no payment is required.

Today over on the SWLing post blog we’ve seen an update. They write:

As you can imagine the response to Titus has almost been overwhelming! Pre-orders far exceeded our imagination and excitement from broadcasters has been very loud. DRM and digital broadcasting seems to be reinvigorated with Titus in 2017. I think we really broke the price barrier that most everyone has been dreaming of and provided the flexibility that has held back the cause.

As posted on

‘Update on availability received from PantronX: “We have been overwhelmed with the response to Titus with orders and request – coupled with an early Chinese New Year that the pre-production date has slipped a bit. Please be patient as we work with our suppliers and add more functions.” ‘

We are doing all we can to push – Chinese New Year is a crazy time – the factories are shut down for 3 to 4 weeks and as you can imagine the stress prior to and the performance after.

Hopefully in the next couple of weeks our website will undergo a much needed update. So much to do – but we are making good headway.

The Titus II Portable SDR
The Titus II Portable SDR