Comparing Two LNA’s for HRIT/LRIT (GOES) Reception

Over on his blog Lucas Teske has been comparing the LNA4ALL and an SPF5189 LNA from eBay on HRIT/LRIT reception from GOES satellites. SPF5189 LNA’s can be found on eBay for less than $8 USD, with free shipping from China, whereas the LNA4ALL costs 27 Euros shipped from Croatia. GOES is a geosynchronous orbit weather satellite which requires a satellite dish or other high gain antenna to receive. It downlinks at about 1.7 GHz, which means that a high quality LNA with low noise figure and good PCB design is needed for reception.

In his post Lucas mentions how he saw a review on eBay stating that the SPF5189 did not work at L-band. However, he found that odd as all of his SPF5189 LNA’s seemed to work just fine with L-band reception. So he did a benchmark comparing the SPF5189 to the PSA5043+ based LNA4ALL which is known to work well on L-band.

From his comparisons he found that the SPF5189 does indeed work well on L-band, and is comparable to the LNA4ALL. He concludes that the reviewer must have received a bad unit, or didn’t know what he was doing.

Lucas also makes an important note regarding the PCB design of these LNA’s. Even though the SPF5189 and PSA5043 chips have similar specs, with LNA’s the design of the PCB is crucial, as a poor design can significantly degrade performance. With the LNA4ALL you can be sure that the design is good, although the SPF5189 LNA’s currently on eBay look to be designed okay as well. Though with some eBay sellers there is no guarantee that you will receive a good board. We note that we have seen some really poor designs for PSA5043 LNA’s out there as well.

The eBay SPF5189 LNA vs the LNA4ALL from 9A4QV
The eBay SPF5189 LNA vs the LNA4ALL from 9A4QV

SDRplay RSP1 & RSP2 Now Support ADS-B Decoding on the Raspberry Pi 2 & 3

Over on the official SDRplay blog, head of marketing Jon has announced that the RSP1 & RSP2 is now compatible with their dump1090 ADS-B decoders for the Raspberry Pi 2 & 3. They write:

ADS-B for both RSP1 and RSP2 now available for the Raspberry Pi 2 & 3 – you can get the software from downloads – http://www.sdrplay.com/downloads

If you are an RSP2 user, make sure you use Antenna Port B.

The RSP2
The SDRplay RSP2

 

Italian Language RTL-SDR Book Now Available

For our Italian readers – recently we received a submission from Marco Cardelli (IZ5IOW) who wanted to let us know that he and his friend Andrea Possemato (IZ5TLU) have published a book in the Italian language about the RTL-SDR. He writes:

The main goal is to introduce the “newbie” in this interesting world of digital radios, demonstrating that SDR is not an expensive technology. Both are the authors also of one of the firsts books about Raspberry Pi in Italian. All books are available on on-line stores, or from the publisher: http://www.sanditlibri.it/sdr-rtl.html

For any other information, please use the contact forms published on Marco Cardelli’s website: http://www.marcocardelli.info.

The book costs 9,90€. We haven’t purchased the book ourselves as we cannot read Italian, so if you decide to purchase the book please leave a review of it in the comments section to inform others on it’s quality.

The Italian RTL-SDR Book Cover
The Italian RTL-SDR Book Cover

New Cross Country Wireless HF Preselector

A new reasonably priced 5-band HF preselector has been released by the company Cross Country Wireless, and it looks perfect for use with SDRs. The price is $56.95 GBP, which right now is about $72 USD. They write:

This can be used to provide additional front end selectivity for HF and medium wave receivers protecting the receiver from strong out of band transmissions, wideband noise and other transmitters on multi-station field days.

As the sunspot cycle declines and more listening is done on the lower HF bands with long wire antennas and strong NVIS signals then the HF Preselector is an ideal accessory to aid receiver performance.

It is invaluable when using simple conventional superhet or SDR receivers such as RTL-SDR dongles with upconverters or SDRPlay with large HF antennas.

It is an ideal tool to reduce ADC overload on the Icom IC-7300 with the new second receiver socket modification kit.

It can also be used with other transceivers that have sockets for a separate receiver input and receive antenna output.

It also covers the medium wave broadcast band for MW DXers.

The Preselector is a passive high Q design that does not use an additional amplifier or require external power.

  • Frequency tuning range: 0.5 to 52 MHz in five bands
  • Input impedance: 50 ohms
  • Output impedance: 50 ohms
  • Bypass option on switch
  • Galvanic isolation between input and output
  • Insertion loss: 2 dB
  • Selectivity: See HP network analyser plots below
  • Connectors: BNC female (RF in 50 ohms), BNC female (RF out)
  • Tough polycarbonate case
  • CCW Z Match
    Overall dimensions: 125 mm (L) x 85 mm (W) x 55 mm (H)
  • Weight: 192 g
The Cross Country Wireless HF Preselecter
The Cross Country Wireless HF Preselector

Titus II SDR Updates

Over on the swling.com blog we’ve seen news of an update regarding the PantronX Titus II SDR. The last update we had was in January. Swling.com contributor Richard Langley writes:

There was a segment on the latest episode of AWR’s Wavescan (9 April 2017) about the Titus II DRM receiver recorded during the recent HFCC meeting in Jordan. In it, it was stated that the shipment of the first 1500 units was expected at the end of March or by the first half of April. Included some discussion of added shielding to prevent digital noise and the high-sensitivity of the receiver compared to other DRM units. 

Head over to the swling.com post to listen to the Wavescan podcast announcement,

The Titus II is an Android Tablet + SDR combination that is due to be released in the near future. Its main purpose is for reception of Digital Radio Mondiale (DRM) which is a digital broadcasting medium used on the HF frequencies, which somewhat replaces standard short wave AM radio. The Titus II hopes to be one of the first low cost receiver solutions for this market and as a wideband SDR it should work for many other applications too. From the advertised frequency range of 100 kHz – 2 GHz we speculate that it will be using the Mirics SDR chipset, which is the same chipset as used in the SDRplay. The target price is under $100 USD.

The Titus II Portable SDR
The Titus II Portable SDR

Reverse Engineering and Controlling an RC Toy Tank with a HackRF and GNU Radio

Last year during a Russian wireless ‘capture the flag’ (CTF) competition one of the goals was to reverse engineer a remote controlled toy tank, and then to control it with a HackRF. One of the Russian CTF teams has posted a thorough write up on the reverse engineering process that was used on the toy tank (the link is in Russian, but Google Translate works okay).

The write up first shows the reception of the signal from the wireless controller, and then moves on to show how to receive it in GNU Radio and obtain a time domain graph of the digital signal. From the pulses it is simple to visually work out the binary string. Next an instruction decoder is created in GNU Radio which automatically obtains the binary string from the signal directly. Then once the codes for back, forward, left and right were obtained it was possible to write another GNU Radio program to transmit these codes to the RC toy tank from the HackRF.

HackRF used to control an RC toy tank
HackRF used to control an RC toy tank

A Tutorial on Using a Raspberry Pi Zero Wireless for ADS-B Flight Tracking

Allaboutcircuits.com contributing writer Mark Hughes has recently posted a tutorial that shows how to use an RTL-SDR dongle with a Raspberry Pi Zero Wireless to track aircraft with ADS-B. As a bonus he also shows how to program and wire up a 64×64 RGB matrix screen to display currently tracked flight numbers.

The Pi Zero is one of the cheapest single board computers available, costing only $5 USD, and the wireless model with WiFi connectivity only costs $10 USD. It is powerful enough with its 1 GHz CPU and 512 MB of RAM to run an RTL-SDR and run several non CPU intensive applications such as ADS-B decoding.

The tutorial starts from the beginning by installing a fresh Raspbian image onto the Pi Zero. He then goes on to show how to install the PiAware tracking and feeding software from flightaware.com. Later in the tutorial he also shows how to collect data straight from the flightaware.com API, and also how to build and control an RGB matrix which can display live flight numbers.

It also seems that FlightAware themselves have recently released PiAware 3.5, which now directly supports the Raspberry Pi Zero Wireless.

Track Overhead Flights with a Raspberry Pi Zero Wireless, a Software Defined Radio, and FlightAware

Using a HackRF as a Beacon Transmitter on a Drone for Antenna Calibration

Over on his Twitter feed Sylvain Azarian (@sylvain_azarian / F4GKR) has been tweeting about his new antenna calibration method which involves the use of a HackRF SDR and Raspberry Pi mounted on a drone.

The idea is to use the drone as a remote beacon which can move all around the antenna. As the drone flies around, the HackRF on the drone emits a data chirp containing GPS telemetry of the drones position. The receiver on the ground decodes this data and also determines the SNR of the received signal. By plotting the received SNR together with the drones GPS position, the radiation pattern of the antenna under test could be determined.

The software is called “RadiantBee” and is developed by both F4GKR and F5OEO. It is available over on GitHub. The flying hardware consists of a quadcopter, GPS, Raspberry Pi 3, HackRF, 10 GHz upconverter, band pass filter and horn antenna. The base station consists of an RTL-SDR dongle, 10 GHz downconverter, GPS and the antenna under test.

[Also seen on Hackaday]

The RadiantBee Quadcopter.
The RadiantBee Quadcopter