Category: Other

SOCORAD32 Now Crowd Funding: ESP32-based Walkie-Talkie with Data Communication

Back in May of 2022 we posted about SOCORAD32 which at the time was pre-announced for future crowd funding. A few days ago Crowd Funding begun and already it's goal has been reached.

The project is described as a "hackable, open source, ESP32 amateur radio board with walkie-talkie functionality and data communication". We note that this is not a software defined radio, rather it's a highly customizable software controlled radio.

The advertising claims that you can communicate between SOCORAD32 devices by voice and text for up to 5km at 2W of power. No commercial or amateur radio license is required to use this radio since it operates in the 400 - 470 MHz license free bands that are available in many countries. Although we note that these bands in many countries may have power restrictions well below 2W, which would restrict range.

In recent updates they note that they have been refining the PCB and now added a battery holder and moved the push to talk button to a new position.

During crowd funding the device is selling for US$80 + $8 US shipping / $18 worldwide shipping.

SOCORAD32 can communicate between devices by voice or text for up to 5km, via license free bands.
SOCORAD32 can communicate between devices by voice or text for up to 5km, via license free bands.

Tech Minds: Demonstrating RTL_433 Running on ESP32 Devices

Earlier in the month we posted about how rtl_433 has been ported to ESP32 devices that are combined with CC1101 or SC127X transceiver chips, such as the low cost LILYGO LoRa 32 boards available on Aliexpress.

Over on YouTube Matt from the Tech Minds channel has uploaded a video showing how to set up rtl_433 on an ESP32 device, and how to set it up with a home automation service like Home Assistant, Node Red or OpenHAB via an MQTT broker.

RTL 433 ON ESP32 DEVICE - MQTT HOME ASSISTANT

Transmitting radio waves without power

Researchers have discovered a way to transmit information wirelessly without power, simply by opening an closing a switch that connects a resistor to an antenna. This effect does not violate any physics - it works because the random thermal noise signature of the transmitter changes when the resistor is connected or disconnected.

The researchers used an RTL-SDR with high gain horn antenna and low noise amplifiers to measure changes in the thermal noise signature of the transmitter.

They also compare their idea to backscatter devices, which are another form of passive RF communications that make use of ambient radio signals such as from TV transmitters. They note that their thermal noise approach has a lower data rate and range compared to backscatter, but their next goal is to try and improve this.

Thermal Noise Transmitter Test
Thermal Noise Transmitter Test

Arinst Dreamkit V2D Reviewed by Fenu-Radio

Back in August of 2021 we posted about the release of a Russian made portable software defined radio receiver called the "Arinst Dreamkit V1D". The Arinst SDR consists of a portable LCD screen and enclosure, with 16-bit ADC, 5 MHz of bandwidth and 1 - 3100 MHz tuning range. It was released for sale in September 2021 and was priced at only $230 + shipping.

It did have some drawbacks involving a lack of preselector filtering, and there being no digital decoding capabilities implemented in the software.

Fenu-radio is a popular tester of various software defined radios and has recently posted a review of the Arinst Dreamkit V2D. Initially he notes how in 2021 he first received his V1D model from Kazakhstan, and noted some problems with the lack of preselection, but other than that it worked well. His unit also had a display defect, however the manufacturer replaced the entire unit with the newer V2D model.

Fenu-radio notes that a battery is no longer included due to restrictions involving the transport of batteries through airmail, so he had to order a separate battery from Aliexpress.  He importantly notes that the polarity of the battery is reversed from what the radio expects, so this has to be manually adjusted by changing the pins on the battery. If this is not done the battery or radio itself could be destroyed.

Other than that, Fenu-radio is impressed with the outer design of the V2D. He goes on to note how the V2D makes use of the R820T2 tuner, the same tuner used in standard RTL-SDR dongles. An up and downconverter is used to expand the range. 

Fenu-radio then goes on to show the features of the radio, shows how it is operated, and provides a few audio examples of some stations received. He concludes positively:

The Arinst V2D is almost a "dream kit". It offers amazingly good reception on long, medium and shortwave without immediately clipping. And that on domestic active antennas. If you work with the manual gain control, you largely avoid intermodulation products and noise. The variety of functions is enormous and of high quality. At that point, you realize how hard Arinst has put in. The V2D can also convince above shortwave. What it particularly lacks here is a search function (scanner).

The case is sturdy and of good quality. But unfortunately there is criticism here. The housing shells were painted in places that shouldn't be painted! The painted flanks of the housing significantly worsen the shielding effect, which becomes noticeable with strong interference in reception if the V2D is operated with a telescopic antenna. The interference is particularly strong in the VHF range. Not only that. During the development of the V2D, far too little attention was paid to decoupling the display to prevent interference radiation in the reception branch. The approx. 4 hours Battery life was unfortunately never reached. After almost 3 hours of operation it was over.

Otherwise, the V2D is great fun. Especially with a remote antenna.

Arinst showed itself to be a very committed manufacturer when it came to correcting errors in the software and implementing suggestions.

At the time of this post the Arinst website and their sales platforms on Aliexpress and eBay does not appear to feature the 'Dreamkit V2D' product and we have no further info on the release date or pricing.

Fenu-radio's image of the Arinst Dreamkit V2D
Fenu-radio's image of the Arinst Dreamkit V2D

rtl_433 ported to ESP32 microcontrollers with CC1101 or SX127X Transceiver Chips

Receiving wireless sensors operating in the unlicensed ISM band has been made almost universal with rtl_433 and RTL-SDRs. However, recently rtl_433 has been ported over for use on ESP32 microcontrollers that are combined with CC1101 or SC127X transceiver chips.

PCB boards that combine these two chips can be found cheaply on Aliexpress as LoRa boards, under the name "LILYGO LoRa 32". If you are unaware, ESP32 chips cheaply combine a WiFi and Bluetooth modem with a microcontroller that is capable of hosting a webserver. CC1101 and SC127X are low cost low power hardware transceiver chips made for IOT devices. We've posted about LILYGO boards in the past as they've been used with interesting projects such as Meshtastic, and for weather balloon tracking.

This project could be useful for home automation as a module has been made available for openMQTTGateway. Instead of dedicating a more powerful Raspberry Pi and RTL-SDR, you can now dedicate a much cheaper and much lower power device to the task. 

[Also seen on Hackaday.]

RTL_433 running on a LILYGO LoRa V2 Board
RTL_433 running on a LILYGO LoRa V2 Board

Upgrading the Mahahit DSP1 and Malahit Chinese Clones into the Mahahit DSP2

Mahiteam is a Russian company that produces the relatively popular Malahit DSP1/DSP2 and Malahit DDC portable SDR radio which are great for shortwave listening, but can also cover up to 2 GHz. Manuel L. has been following developments and notes that Malahiteam are offering the ability to upgrade their DSP1 (and any DSP1 Chinese clone) into Malahit 2 units by sending the device in for a chip replacement. Manuel writes:

Hi. Recently it is possible to upgrade the Malahit DSP1 (original) and also the China clones (if registered in Russia) of the Malahit with a new CPU and if necessary a new audio codec chip. This upgrade has been officially released by the Malahiteam the developers.

This allows custom DSP2 firmware to run on the DSP1 and clones. This makes the device more powerful and also has the option of installing a Bluetooth board and controlling it via the software, as is the case with the DSP2.

This upgrade can be carried out directly in Russia by the Malahit team.

For Europe this is done by Jochen Köster DC9DD (Malahit Servise Europa) who converted the first DSP1 and China clones outside of Russia.

In the US, the future KD9NXV makes Mark Roy (USA Service Malahit).

I have tested the first conversions outside of Russia and it is a very big upgrade of the devices. They work a lot better now. I have shown this in several YouTube films. More information and contacts to the service teams outside of Russia can be found at Telegram and the Malahit Facebook group

https://t.me/+BOQmKPgV4lM2NDZi

https://www.facebook.com/groups/malahitsdrinternational/

YouTube Video Upgrade Malahit DSP1 and China Clone:
https://youtu.be/h9zepfkyK3Q
https://youtu.be/-v5Iuv7pmHU
https://youtu.be/6Z-hecUeMG0
https://youtu.be/iBWN2HHLQ94

The Malahit DSP2
The Malahit DSP2

tinySA Ultra Reviews: A 0.1 MHz – 6 GHz Spectrum Analyzer for $120

A few weeks ago the tinySA Ultra was released. This is a spectrum analyzer capable of operating between 0.1 - 800 MHz, or 0.1 MHz - 6 GHz with the 'Ultra' mode enabled. A spectrum analyzer is a tool that allows users to visualize signals on the radio spectrum.

Previously the standard tinySA was released back in 2020. The Ultra version brings enhancements to the frequency range, signal generator range, bandpass filter range as well as an optional 20dB LNA, and a larger 4 inch color display. 

The TinySA Ultra costs US$119 + shipping direct from the Aliexpress store in China, or $129.95 from R&L in the USA (currently out of stock). The full list of resellers can be found at https://tinysa.org/wiki/pmwiki.php?n=Main.Buying.

We wanted to thank RTL-SDR.com reader Ben for providing us with links to a bunch of reviews of the tinySA Ultra which we are posting below.

The tinySA Ultra
The tinySA Ultra

GNU Radio Conference 2022 Talks Available on YouTube

During September 26 - 30 GNU Radio Conference 2022 was held in Washington DC. GNU Radio Conference (aka GRCon) is an annual conference centered around the GNU Radio Project and community, and is one of the premier software defined radio industry events. GNU Radio is an open source digital signals processing (DSP) tool which is used often with SDRs.

A few days ago videos of all the presentations were released on their YouTube channels, and all the talks can be found on this playlist. The videos contain a mix of in person and remote talks. A schedule of all talks can be found on the GNU Radio website.

GRCon22 - GNU Radio Project Update