Tagged: HF

Improving Reception on the Malachite DSP via USB Grounding

Thank you to Mitsonobu Saitou for writing in and sharing with us a product that he has created which improves reception on of the Malachite DSP software defined radio and other shortwave radios by up to 20dB by improving the grounding. It appears to work by using the negative USB line as a ground via a modified USB cable with grounding clip on the other end. The product is available via Amazon Japan with international shipping.

The Malachite DSP is a portable battery powered software defined radio with built in screen. It is popular amongst shortwave listeners.

Saitou writes the following summary, and full details about the product are available on his blog (link uses Google Translate to translate from Japanese to English): 

Today's item is "Dokodemo Earth KUN". This is an item to pull the ground wire from the charging connector of DCL radios and Mlachite DSPs.

The sensitivity of the receiver will be improved by strengthening the grounding. This is how I applied it.

It is easy to connect by pulling out the ground wire from the charging connector instead of the antenna jack.

It can also be used as a loop antenna by connecting the ground to the antenna.

We have confirmed the effectiveness of this product outdoors. Users who have used this item have experienced a significant increase in sensitivity. 

Malachite DSP and SWL Radio USB Grounding Enhancement Cable
Malahit/Malachite DSP+「どこでもアースくん」


TechMinds: Testing the RadioBerry an HF SDR Transceiver Raspberry Pi Hat

The RadioBerry is a HF transceiver board designed to be used as an add on 'hat' for the  Raspberry Pi. It uses the same AD9866 chip as the Hermes Lite 2 SDR which gives it a 12-bit ADC with one RX and one TX channel, a maximum bandwidth of up to 384 kHz, and an operating frequency range of 0 to 30 MHz. 

In the video TechMinds shows how to connect and setup the Radioberry software on the Pi and how to stream from the Pi to SDR-Console V3 on a PC. He goes on to demonstrate the Radioberry receiving HF signals, noting that the performance is good, although he uses an Ethernet connection and Pi 4 for best performance.

TechMinds notes that he will test the transmit functionality in a future video, once he receives a preamp designed to be used with the Radioberry.


Decoding HFDL ACARS with a WebSDR and PC-HFDL

In the previous episode Rob from the Frugal Radio YouTube channel showed us how to decode HF ACARS using PC-HFDL and an HF capable SDR such as the Airspy HF+. In that episode he mentioned that it is possible to decode HF ACARS using a WebSDR as well.

In this weeks episode, Rob shows us how to do just that, making use of WebSDR receivers and the PC-HFDL software. Like the previous episode we see how to plot the aircraft HF ACARS position data on Google Earth and how to read and interpret some example messages received.

Decoding HFDL ACARS with a WebSDR and PC-HFDL

Frugal Radio: HFDL HF ACARS Decoding Tutorial

In Rob's latest episode of his excellent aviation communications series on his Frugal Radio YouTube channel he shows how to decode aircraft HF ACARS (HFDL) using a software defined radio. HFDL is short for "high frequency data link", and is a method aircraft use for sending text and data communications to ground stations. It is an alternative to VHF or satellite ACARS communications methods.

In the video he shows how he's been able to receive HFDL from all over the world using a simple HF dipole antenna and an Airspy HF+ Discovery. He goes on to show how to find HFDL signals, and how to decode signals using SDR# and the PC-HFDL software. Finally he shows examples of aircraft received, and how to interpret some of the information being received, including location information.

How to decode HF ACARS (HFDL) free with your SDR - Monitoring Aviation Communications Episode 8

Frugal Radio: Turning Scrap Wire into an Effective HF Dipole

In this weeks video Rob from his Frugal Radio YouTube channel shows us how he's turned an old piece of scrap electrical extension cord into an effective HF antenna for his Airspy HF+ SDR. The scrap wire is combined with a US$15 NooElec 9:1 balun which helps improve the impedance match of the antenna. He then stretches the dipole out through his backyard and then hooks it up to his Airspy HF+.

The results show good reception across the 20m, 80m, 40m amateur radio bands, as well as on HF ATC aircraft communications, US coast guard weather information broadcasts and the AM broadcast band.

I made an HF Dipole for free! Reception was good on my AirSpy HF+ Discovery SDR!

A Hi-Z to 50 Ohm Impedance Matching Transformer for Improving HF/SW Reception

Thank you to Mitsunobu for writing in and sharing news about the release of his new product which is a Hi-Z (high impedance) to 50 Ohm matching transformer. This transformer allows you to use small antennas such as short telescopic whips for HF/SW reception on software defined radios.

Generally for HF reception you would want to use a full sized antenna, which can be many meters long and certainly not portable. However, by using an high impedance transformer it becomes possible to use smaller portable antennas. Reception with a small antenna and transformer will still be suboptimal compared to a full sized HF antenna, however, if the signals are strong enough the transformer will allow you to receive them decently.

In the tests shown on his blog (in Japanese, use Google Translate) he shows how the transformer adapter can be connected to a small telescopic whip and Malachite DSP SDR for portable use. Later he also shows how the adapter can make our Dipole Kit antenna work well for HF on a RTL-SDR Blog V3 with direct sampling.  

The product is only available via Amazon in Japan. However, Mitsunobu notes that Amazon.jp offers international shipping. He offers the transformer by itself, and a version including a short telescopic whip antenna.

Hi-Z to 50 Ohm Antenna Transformer for HF/SWL

Using an RTL-SDR as a Panadapter with an Automatic Antenna Switcher

Over on YouTube "Gadget Talk" has uploaded a useful video showing how he set up an RTL-SDR V3 based panadapter system to use with his traditional amateur radio. The setup involves utilizing an antenna switcher which allows him to transmit with the RTL-SDR connected to the same antenna. The switch grounds the SDR during transmission, ensuring that the RTL-SDR is not overloaded with the transmit signal.

In the video he also shows how to set up the HDSDR receiver software and the HRD Rig Control software for controlling the hardware radio through the software and vice versa.

SDR Panadapter Using an Antenna Switcher

Tech Minds tests out the YouLoop HF Passive Loop Antenna

Over on YouTube Tech Minds has uploaded a new video where he unboxes and tests a YouLoop HF Passive Loop Antenna with his Airspy. The YouLoop design is also known as a Möbius loop, or noise cancelling passive loop "NCPL". The passive nature of the antenna means that highly sensitive radios will work best with it, however limited results may still be obtained with other radios. The advantages are extremely low levels of interference pickup and high portability.

In the video Tech Minds explains the specifications of the antenna before demonstrating the antenna receiving the HF bands with an Airspy + SpyVerter. He also tests the loop on VHF, demonstrating its ability to receive a distant 2M beacon.

We note that we sell official YouLoop antennas on our store for $34.95 including free shipping to most countries.

YouLoop HF Passive Loop Antenna