Author Archives: Thomas

Bedside radio: Jeff ousts the Sangean WR-2 in favor of the Grundig G4000A

(Source: The Herculodge)

Our friend, Jeff McMahon, over at the Herculodge blog has just replaced his bedside radio–he writes:

Inexplicably, the Sangean WR-2 wasn’t getting 89.3 KPCC without static, distortion, and bleed-in from another station, over the last few weeks, even with the wire FM antenna attached to the back of it. Who knows why FM reception is subject to variation. It could be the weather.

In any event, I put the Sangean WR-2 in my daughter’s room (she gets her pop station MyFM 104.3 very easily, with the pigtail antenna on the back) and put the 13-year-old Grundig G4000A by my bedside. With the telescopic FM antenna alone, KPCC has a weak signal, evidenced by the Grundig’s reception meter, but when I put the wire SW antenna to the side SW antenna port, the reception is strong and clear.

Over the years, I’ve had many portables, including the Degen 1103, and some old Tecsun models from about 10 years ago. They all suffered from weak tin speakers. Not so with the Grundig G4000A. The speaker sound is very pleasing.[…]

Continue reading at the Herculodge.

Building a Raspberry Pi magnetometer network

1 Reply

Source: Ciarán D. Beggan and Steve R. Marple

(Source: Southgate ARC)

Ciarán Beggan of the British Geological Survey describes how a network of 9 Raspberry Pi magnetometers were deployed to schools around the UK to measure geomagnetic storms

As computers such as the Raspberry Pi and geophysical sensors have become smaller and cheaper it is now possible to build a reasonably sensitive system which can detect and record the changes of the magnetic field caused by the Northern Lights (aurora).

Though not as accurate as a scientific level instrument, the Raspberry Pi magnetometer costs around 1/100th the price (about £180 at 2019 prices) for around 1/100th the accuracy (~1.5 nanoTesla). However, this is sufficient to make interesting scientific measurements.

During 2017, a network of 9 Raspberry Pi magnetometers were deployed to schools around the UK from Benbecula to Norwich. On September 8, 2017 a large geomagnetic storm was captured by the school magnetometers. Using these data and the array of other magnetometers around the North Sea, we were able to recreate the spatial and temporal changes of the magnetic field during the storm in great detail. The two phases of the storm show the westward (night time) and eastward (daytime) flow of the auroral electrojet currents in the ionosphere.

Source http://www.mist.ac.uk/nuggets

Download the paper Building a Raspberry Pi school magnetometer network in the UK
https://www.geosci-commun.net/1/25/2018/gc-1-25-2018.pdf

Click here to read at the Southgate ARC.

WRTH 2019: Now at Book Depository

Using bus service to ship heavy vintage radios

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Many thanks to SWLing Post contributor, James Branch, who shares the following comment regarding the shipment of heavy vintage radios:

On the issue of shipping Boat Anchors, I’ve had good experiences using Greyhound Package Express, Tough-bin structural foam footlockers and proper padding.

The parcel is loaded at the bus station of origin and usually remains on that bus to its destination without having to survive a sorting center or multiple unhappy loading personnel.

It may be inconvenient to drop off and pick up at the bus terminal, but considering the irreplaceable nature of these rigs, it’s worth the effort.

http://www.shipgreyhound.com/e/pages/Home.aspx

I had no idea! Thank you for the tip, James!

The NSA’s Software Defined Radio application “RedHawk” is now open source

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Many thanks to SWLing Post contributor, Andrew, who writes:

Not kidding, a friend told me that NSA released a bunch of software to open source, the main list being here:

https://code.nsa.gov/

While looking at the list of projects on that page, halfway down the page, I found a project called “RedHawk” which is described as:

“A software-defined radio (SDR) framework designed to support the development, deployment, and management of real-time software radio applications.”

Now, being curious I opened the github link:

https://github.com/redhawksdr

[It] contains quite a number of subprojects, modules and other stuff, then I checked the main “RedHawk” project:

https://github.com/RedhawkSDR/redhawk

Here’s the documentation:

https://redhawksdr.github.io/Documentation/index.html

It seems really interesting; apparently it allows to define a wealth of processing stages (e.g. filters, converters…) and connect them to process signals coming from an SDR; I think it may be a very interesting and useful tool to fiddle/experiment with SDR receivers, if I’m not wrong it may allow to push an SDR to the limits, improving its performance, and may also be useful to write SDR software!

Fascinating! Thank you for the tip, Andrew!

Post Readers: It appears this project has been in the public domain for a little while. Please comment if you’ve tried implementing RedHawk in your SDR system!

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Australia: International broadcasting, soft power and the wisdom of the crowd

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Many thanks to SWLing Post contributor, Nigel Holmes, who writes:

Here are a couple of interesting url following the joint Australian DFAT & DCA Review of Broadcasting Services in the Asia Pacific. [One] gives a good overview and the [other] is a concise assessment of HF and Radio Australia in the role of broadcasting to remote areas. Have a look. Former RA Head Jean-Gabriel Manguy made a submission, I did not this time. The submissions are in the public domain.

Click here to read Trevor Bird’s submission (PDF).

Click here to read Jean-Gabriel Manguy’s submission (PDF).

(Source: Lowy Institute – The Interpreter by Geoff Heriot)

International broadcasting: the ABC vs the wisdom of the crowd

The findings of two related government reviews – on international broadcasting, and soft power – should offer an incoming Australian government the potential of a substantial policy reset following the general election in May. Specifically, they may help clarify the purpose and place of state-funded international broadcasting/digital media in Australia’s foreign relations, following a decades-long cycle of investment and dis-investment.

Shortly before Christmas, the Department of Communications published most of the 433 submissions (92 private individuals, 31 organisations or groups, and 310 signatories to a pro-forma submission) made to the first of those reviews, Australian Broadcasting Services in the Asia Pacific, excluding those whose authors wished them to remain confidential. Finalisation of the broadcasting report precedes the related Soft Power Review, being undertaken by the Department of Foreign Affairs and Trade, which has proposed a completion date of around March.

So it is timely to take note of the wisdom of the crowd, as expressed through the more discursive submissions to the broadcasting review, and to compare them with the institutional perspective of the ABC as the responsible agency for international broadcasting.[…]

Click here to read the full article.

Fast Radio Bursts (FRBs) from a distant galaxy detected

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Many thanks to a number of SWLing Post contributors who’ve shared the following news:

(Source: Southgate ARC)

Mysterious radio signals from deep space detected

BBC News report astronomers have revealed details of mysterious signals emanating from a distant galaxy, picked up by a telescope in Canada.

The precise nature and origin of the blasts of radio waves is unknown.

Among the 13 fast radio bursts, known as FRBs, was a very unusual repeating signal, coming from the same source about 1.5 billion light years away.

Such an event has only been reported once before, by a different telescope.

“Knowing that there is another suggests that there could be more out there,” said Ingrid Stairs, an astrophysicist from the University of British Columbia (UBC).

“And with more repeaters and more sources available for study, we may be able to understand these cosmic puzzles – where they’re from and what causes them.”

The CHIME observatory, located in British Columbia’s Okanagan Valley, consists of four 100-metre-long, semi-cylindrical antennas, which scan the entire northern sky each day.

The telescope only got up and running last year, detecting 13 of the radio bursts almost immediately, including the repeater.

Read the full BBC News article
https://www.bbc.co.uk/news/science-environment-46811618