Category Archives: New Products

USB Battery Pack Keep-Alive Load Kit

(Source: Southgate ARC)

USB power banks are a convenient way of powering low power USB devices in the field. Unfortunately, as they are designed for charging phones and tablets, many have an internal electronic cut out circuit that switches power off below a certain current draw. The exact current that they switch off at varies from pack to pack.

Although there are circuits on the internet that purport to solve this problem by applying a pulsed load, we found this did not work with all power banks. As a result we designed a neat variable electronic load to address this problem.

Available as a kit, using it is easy; just plug it into your power bank, plug your target device into it and adjust the current draw until the pack remains on.

http://www.sotabeams.co.uk/usb-battery-pack-keep-alive-load-kit/

This could be a handy tool for those of us who use USB battery packs for portable work. SotaBeams originally created this simple kit for the WSPRlite.

Photo of the new Elad FDM-S3

Many thanks to SWLing Post contributor, Rafman, who shares the following photos that were originally posted by Alberto (I2PHD) on the Elad email reflector. Alberto noted:

“Here it is…. shown for the first time today at the Montichiari Ham Fest. Price TBD….”

Many thanks, Rafman, for the tip!

We’ll continue to post FDM-S3 updates as they become available. I will also plan to review the FDM-S3 when it hits the market.

Click here to view the Elad website.

Cornell engineers invent two-way radio on a single chip

Many thanks to SWLing Post contributor, Tom Ally, who shares the following news via the Cornell Chronicle:

Engineers devise two-way radio on a single chip

Two-way communication requires, of course, both send and receive capabilities. But putting them in the same device requires a filter between the send and receive circuits to provide signal isolation.

Without a significant filter, communication would be impossible.

“Your transmit signal is [10 to the power 14] times stronger than your receive signal,” said Alyosha Molnar, associate professor of electrical and computer engineering (ECE). “That’s 100 trillion times stronger – that’s a really hard problem.”

But researchers in Molnar’s lab have offered up a solution.

Molnar and collaborator Alyssa Apsel, professor of ECE, have devised a method for both transmitting and receiving a radio signal on a single chip, which ultimately could help change the way wireless communication is done.

Their work is described in “A wideband fully integrated software-defined transceiver for FDD and TDD operation,” published online Jan. 27 in the Institute of Electrical and Electronics Engineers’ Journal of Solid-State Circuits. Doctoral student Hazal Yüksel and Dong Yang, Ph.D. ’15, are co-lead authors.

Separating the send and receive bands is difficult enough, but the problem is compounded by the ever-increasing number of bands in the latest devices. From GPS to Bluetooth to Wi-Fi, each band requires a filter to stop the strong transmit signals from drowning out reception.

Molnar and Apsel have come up with an ingenious way to separate the signals. Their idea lies in the transmitter – actually a series of six subtransmitters all hooked into an artificial transmission line. Each sends its signal at regular intervals, and their individually weighted outputs are programmed so that they combine to produce a radio frequency signal in the forward direction, at the antenna port, while canceling out at the receive port.

The programmability of the individual outputs allows this simultaneous summation and cancellation to be tuned across a wide range of frequencies, and to adjust to signal strength at the antenna.

“In one direction, it’s a filter and you basically get this cancellation,” Apsel said. “And in the other direction, it’s an amplifier.”

“You put the antenna at one end and the amplified signal goes out the antenna, and you put the receiver at the other end and that’s where the nulling happens,” Molnar said. “Your receiver sees the antenna through this wire, the transmission line, but it doesn’t see the transmit signal because it’s canceling itself out at that end.” […]

Continue reading on the Cornell Chronicle.

pantronX Titus II quick update

Many thanks to SWLing Post contributor, Ed, who notes:

I just received a status update on the pantronX Titus II portable SDR from Mike, their chief engineer.

Mike said the self-contained SDR portable will include “SoapySDR as the interface to make it much easier to roll your own SDR app.” Here’s some info about SoapySDR:

https://github.com/pothosware/SoapySDR/wiki

Mike also said, “To be 100% truthful, our biggest push right now is for the international MW & SW broadcasters. They want to go DRM digital is the worst way!”

You might want to share this news with SWLing Post readers.

Thank you for the update, Ed! Click here to view the pantronX website.

Grace Digital Mondo+ Kickstarter

Many thanks to SWLing Post contributor, Tom Ally, who writes:

I remember that article you wrote about Wi-fi radios and just saw this Kickstarter on Facebook that may interest you:

https://www.kickstarter.com/projects/1209003580/mondo

[T]hey are saying it is supposed to ship out sometime next month. [S]ome of the things it has –over the old Mondo–is Bluetooth 4.1 and Chromecast built in.

Thank you, Tom! Here’s the product description from Kickstarter:

The home audio market is evolving, and Grace Digital is leading the way. We combined the latest Wi-Fi audio streaming technologies from Google, added Bluetooth audio streaming, and over 30,000 AM/FM/HD radio stations from around the corner to across the globe. The Grace Mondo+ can even be controlled by the Google Assistant on devices like Google Home, the front panel controls, free smartphone apps, or the included remote control. We wrapped the technology in a beautifully crafted cabinet, and drive the audio with custom made speaker drivers and high performance class D digital amplification, ensuring the best possible listening experience in a perfectly compact design. We hope you love the Mondo+ as much as we do!

This is an “all or nothing” campaign, meaning it’ll have to be fully funded for the production run to become reality.

As a Kickstarter supporter, the pricing is in line with the Grace Digital Mondo (we reviewed last year).

I am still quite happy with my Como Audio Solo, so will not plan to back the Mondo+ at this time. If I was interested, I would splurge for the $174 Early Bird package which includes a Lithium Ion battery pack. Shipping could be as early as April 2017.

Check out full details and a video on Kickstarter.

Thanks, Tom, for the tip! I would certainly welcome a review of the Mondo+ from any Kickstarter backers!