Category Archives: Articles

Guest Post: Richard builds a WiFi radio with the Raspberry Pi

Many thanks to SWLing Post contributor, Richard Schreiber (KE7KRF), who shares the following guest post:


Yet Another Internet Radio!

by Richard Schreiber (KE7KRF)

After deciding that an internet radio could be an important source of entertainment in our household, we formulated a few general guidelines:

  • We opted not to use an aggregator but would pick and choose stations we enjoyed and discover the URL’s ourselves. Also would be satisfied with a couple of dozen stations. Based on a recent decision to pare down the number of TV channels we were paying for, having access to hundreds of stations seemed impractical and unnecessary.
  • The price had to be affordable, thus eliminating many stand-alone, commercially available internet radios.
  • We already owned a quality portable speaker (Bose SoundLink Mini) so the internet radio didn’t need to duplicate that component.
  • Didn’t want to tie up nor be tethered to a laptop, tablet, or netbook. We predicted that would eventually lead to less and less use of the radio.

After some research, coupled with the fact I already had some experience with Raspberry Pi computers, that small device appeared to be our best choice. I had recently purchased the newer 2 B model, which has plenty of computing power, and had installed Ubuntu Linaro as the OS. (As an aside, this OS has not to my knowledge been upgraded for the latest Raspberry Pi 3). There are several other operating systems that will work just as well including the official Raspbian OS available through the Raspberry Pi Foundation.

I installed the MPD music player daemon and its client MPC, which is used to add to and delete station URL’s from the playlist, control volume, etc. An important find was the iPhone app called MPod which provides remote wireless access to the features of MPC. At the moment it is a free app for the iPhone (in my case the iPod Touch).

For portability, my Raspberry Pi is being used “headless”, meaning it is not connected to a monitor, keyboard or mouse. If maintenance is required you can use PuTTY, a SSH and telnet client, wirelessly from a Windows (or MAC?) PC, using a command-line interface. Mainly this is needed to shut down the Raspberry Pi properly before turning off the power, but it boots completely on its own when powered up. The MPod app will then load the playlist of stations and let you start playing the radio without direct access to the Raspberry Pi.

The sound output of my Raspberry Pi is connected to the auxiliary port of our Bose SoundLink Mini Bluetooth speaker. But instead of trying to implement Bluetooth on the Raspberry Pi, I took the easy way out and use a direct connection. The sound reproduction from this setup is very good, though audiophiles might be somewhat more critical.

The above represents a minimal investment if you already have a good speaker on hand. It does require some on-line research and learning at least enough to install the OS and software. The good news is that there are many websites and forums providing step-by-step instructions and helpful hobbyists willing to explain some of the more cryptic aspects. A few of the websites that I found to be helpful:

http://www.instructables.com/id/Arduino-Raspberry-Pi-Internet

http://cagewebdev.com/raspberry-pi-playing-internet-radio

https://learn.adafruit.com/raspberry-pi-radio-player-with-touchscreen

A couple of these also explain how to add a display to your Raspberry Pi internet radio.

Our Raspberry Pi radio is on each evening and has been trouble free. It is worth mentioning that this is a very portable setup, and can even be powered by a battery pack (the kind used for recharging tablets and cell phones) for a few hours. Of course you need to be near a wifi hotspot.


Thank you, Richard! What a great way to use the inexpensive Raspberry Pi. I have a spare Pi2 and an amplified speaker here at the house. Though I don’t need another WiFi radio, it would be fun putting this little system together. 

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Oxford Shortwave Log: Sony ICF-SW77 vs ICF-SW55 vs Tecsun PL-310ET

Hi there, I recently posted an article regarding a couple of recent DX catches with the Sony ICF-SW77 receiver and went on to explain the background to a multi-receiver test I had started conducting, comparing it with its stablemate of the time the ICF-SW55 and, just for the hell of it, a more modern, yet modest portable in the shape of the brilliant little Tecsun PL-310ET.                                                Sony ICF-SW77

The initial results confirmed the performance of the Sony receivers to be very similar and thus the justification for the original price delta of £100 in the UK to remain in question. The first target signals chosen and in the original post were ABC Northern Territories on 4835 kHz and Radio Mali on 9635 kHz.

Sony ICF-SW55                                                        Tecsun PL-310ET

The initial results reinforced my view that the PL-310ET is a great portable for relatively small money; it managed to copy both signals, something you might not expect from what is essentially a budget receiver.

Below are links to the next 6 reception videos on the Oxford Shortwave Log YouTube channel and once again, featuring all three radios. I have used two different antennas during the testing – a 75 metre longwire and the Wellbrook ALA1530 active loop, running on batteries. The accompanying text description to the videos indicates which antenna was used.

Although the PL-310ET clearly struggled with the more ‘hard-core’ DX signals amongst those detailed below, the fact is, for less than £40 in the UK (and I’m certain even less elsewhere), Tecsun have delivered us a portable radio that really is capable of real DX. With DSP, a number of audio bandwidth filter options and great sensitivity, it’s a winner for beginners to DXing and to ‘old hands’ who want a radio in their pocket when they take the dog for a walk for example (something I do all the time – you never know when you’re going to come across the next barbed wire fence!). As for the Sonys, well I’m still not convinced one way or the other that the £100 price delta on the original price of the ICF-SW77 was worth the money – the ICF-SW55 is pretty close to it in terms of delivering discernible audio across all of the below reception videos. I’d be interested in your views and note there will be a final posting on this 3-way receiver comparison to wrap things up. In the meantime, thanks for reading/watching/listening and I wish you good DX!

Enbedded videos follow below.

Clint Gouveia is the author of this post and a regular contributor to the SWLing Post. Clint actively publishes videos of his shortwave radio excursions on his YouTube channel: Oxford Shortwave Log. Clint is based in Oxfordshire, England.

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Washington Post: “A big change to U.S. broadcasting is coming”

View of the Capitol Building from the roof of the Voice of America on 330 Independence Ave., S.W.

Many thanks to SWLing Post contributor, Richard Langley, who shares this editorial from the The Washington Post:”

“FOR YEARS, members of Congress have fumed about what they regard as ineffective U.S. public diplomacy, including the failure of broadcasting operations such as the Voice of America and Radio Free Europe/Radio Liberty to match the reach and apparent influence of networks such as Russia’s RT and Qatar’s al Jazeera. A frequent and arguably fair focus of criticism has been the Broadcasting Board of Governors, the body created to supervise government-funded media outlets while serving as a firewall between them and the political administration of the day.

A radical change to that system is now coming — and it looks like one that Vladi­mir Putin and Qatar’s emir might well admire. An amendment quietly inserted into the annual National Defense Authorization Act by Republican House leaders would abolish the broadcasting board and place VOA, RFE/RL and other international news and information operations under the direct control of a chief executive appointed by the president. The new executive would hire and fire senior media personnel and manage their budgets.

[…]The point of board governance was to prevent direct political interference in programming by the White House, State Department or other agencies. It was a guarantee that for decades has helped to attract journalistic talent to the broadcasting organizations, as well as listeners seeking reliable information. The board of governors had serious problems: Its members served part time, and not all took their duties seriously. But the system’s biggest flaw was remedied three years ago with the creation of a chief executive position.

The new reform, driven by House Foreign Affairs Committee Chairman Edward R. Royce (R-Calif.), enhances that executive’s power and makes him answerable to the White House rather than the bipartisan board. A new advisory panel will be created, but it will be toothless: Its members will also be nominated by the president from a pool provided by Congress.[…]”

Click here to read the full editorial at The Washington Post online.

Also, Richard points out this article in BBG Watch which highlights comments from Dan Robinson.

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Guest Post: An Unusual Night for CB

Many thanks to SWLing Post contributor, Mario Filippi (N2HUN) for the following guest post:


An Unusual Night for CB

by Mario Filippi (N2HUN)

December 2nd was an unusual night for CB (Citizen’s Band) radio, as the band was open late (0030 GMT) when I turned on the President Washington CB radio just to see who was on. First stop was Channel 19 (27.185 MHz), the trucker’s channel, where the QRM was high, due to the skip from the many truckers on the channel. Earlier in the day this channel was very quiet as was the rest of the band. The fact that Channel 19 was pinning the S meter after dark was a big hint that the band might be open. And it certainly was!

Uniden President Washington AM/SSB Base Station

Being a CB’er from back in the 70’s (call sign KBN-8387), this band was my first serious introduction to two-way radio communication, and after 40+ years it’s still an enjoyable experience to listen in to the local, and sometimes DX chatter. For the most part the CB band mimics 10 meters, basically open during the day (except when sunspot numbers are low) and closed at night. That’s the usual drill, but Mother Nature doesn’t always go by the playbook and sometimes the band is opened at the darnedest times, sometimes even after midnight!

So this evening around 8:30 EST the President Washington CB base station was fired up and CB operators were heard in Maine, Illinois, and as far as Wisconsin, definitely what would be considered out of the ordinary range of CB, which is generally several miles. Now FCC rules still state that it’s illegal to communicate over 155 miles but it’s a non-issue when the band’s open. For the most part, AM is used on most of the channels but you’ll find LSB activity on Channel 36 (27.365 MHz). And when the band gets busy and crowded, you’ll hear LSB QSOs from Channels 36 – 39 (27.365 – 27.395 MHz) as sidebanders spread out among the channels so that they can work each other through the QRM.

To get a better idea of what the CB band “looks” like during a band opening, a spectral scan of the band (26.965 – 27.405 MHz) would be useful. This can be achieved using an SDR dongle, such as the RTL-SDR.com version which is a diminutive broadband receiver with an analog to digital converter and covers from about 26 – 1670 MHz. Used in conjunction with an up-converter (from Nooelec), software such as SDR# (SDR Sharp) and a computer (Smartphone apps are available also) you’ll be able to put up a spectral scan of the band as well as hear what’s happening.

RTL-SDR.com dongle – a small broadband receiver covering all modes

Nooelec’s Ham It Up RF Upconverter expands dongle’s receiving range to the entire HF and MW band

As the old adage goes, “a picture is worth a thousand words” so tonight the SDR dongle, along with SDR# software was fired up to get an idea of how many stations were on during the opening. The antenna used was an S9 43 foot vertical, the same one I use for HF. Using the dongle, it’s an easy feat to visualize the entire CB band on the spectral scan, which is a plot of frequency (X axis) versus signal strength (Y axis). The top half of the screen is the spectral scan and the lower half is the “waterfall” which is a time lapse recording of the spectral scan.

Screenshot of CB Band (wide red stripe) during tonight’s opening.

Normally at this time of night a spectral scan of the CB band would be flat-lining, but as you can see there are plenty of stations conducting QSOs, with the stronger stations having higher peaks and more intense tracings on the waterfall. Seeing the entire CB band visually gives one lots of information such as what channels are active, how many stations are on, what stations might be running higher power (limit is 4 W AM, 12W PEP SSB output), whether outbanders are active or whether DX stations outside the US are partaking of the opening.

Over the years I’ve heard the CB band open beyond midnight and on a winter’s night during a snowstorm. Some openings have lasted for hours. Last year, using the mobile CB, operators from Europe, the Caribbean, and as far away as Australia were heard during my commute to work. At the opposite extreme some days all you’ll hear is ignition noise, hihi. It’s a lot like 10 meters and even a bit like 6 meters; you never know what surprises Mother Nature has in store. Spin the tuning dial over to the CB band and take a listen one of these days.


Thank you so much, Mario!

Only a few weeks ago, I noticed on my SDR’s wideband spectrum display that the 11 meter band was very active.  I started listening around and was absolutely amazed at how organized some of the nets were and how reliable skip was. Signals were blanketing all of the eastern US and even into the west. Sometimes I think there are openings on the 10 meter band, for example, but there are so few users there in comparison, no one notices. The CB frequencies are pretty much always active, when conditions are favorable for DX, everyone instantly notices!

Many might not realize that even their portable shortwave radio can tune the CB frequencies. Thank you again!

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Guest Post: The Story And Restoration Of My Hallicrafters SX-42

halllicrafters-sx-42-front-panel

Many thanks to SWLing Post contributor, Arthur Smith, who shares the following guest post:


The Story And Restoration Of My Hallicrafters SX-42

by Arthur Smith

As a junior high student way back in 1978, I had a natural interest in radios. My dad was a ham radio operator, electronics engineer, and designer. We always had cool, exotic radios and electronic gadgetry around the house. He was also in the Korean War, in the US Army Corps of Engineers, with access to a wide variety of equipment. He often told me the story of how he became interested in radio at an early age, and how he saved up for expensive radio gear, with a little help from my grandparents. Back in 1946, Hallicrafters was THE brand to own, and their postwar designs from Raymond Loewy, were catching the eye of many enthusiasts. The SX-42 was being hyped up in Hallicrafters ads as the ultimate radio to own, one that could tune the shortwave and ham bands, and beyond. I don’t know the complete story, but prior to acquiring his SX-42, my dad also purchased an S-38 and S-40. Never satisfied with “good and better”, my father wanted “the best”. All 15 tubes and 50-plus pounds of boatanchor.

Always ambitious and industrious, he mowed lawns, repaired motorcycles, and did odd jobs for neighbors in his suburban Boston neighborhood. He worked smart, and worked hard. And that fall, bought his SX-42.

halllicrafters-sx-42-front2

The radio, we think, was about $279, which would make it the equivalent of almost $3500 in today’s dollars. He heard the start of the Cold War, and the Soviet Union’s Sputnik. And the birth of Rock and Roll on FM! He graduated high school, went away to the Korean War, serving two Tours of Duty. He came back home, and became an electronics engineer. And a licensed ham radio operator.

Moving ahead to 1978, and yours truly had the radio bug, in the worst way. Not as ambitious or as savvy as my father, a classmate, who was also a ham radio operator, told me about a National HRO he had, with some coils, and maybe needing some work. My Dad came home from work, and I just had to tell him about this great opportunity, which of course, would require his financial backing. At this point, the SX-42 and his other two Hallicrafters were seeing “backup” duty, having long since gone solid state in his post. “Hey, I’ve got an idea!” When a Dad says that, a son usually wants to run. Not in this case. “How about we give you my SX-42?!” Gee, twist my arm. I had loved watching those mesmerizing green back lit dials, S meter, and geared tuning knobs. Unfortunately for my classmate, he had to keep his National. Fortunate for me, I had my father’s SX-42!

That radio logged my first 100 countries, including QSL cards from countries and stations no longer in existence. It heard the fall of the Berlin Wall. And, it was at the heart of my school Science Project, which made Science Fair, featuring an experiment on longwire shortwave radio reception.

halllicrafters-sx-42-open

halllicrafters-sx-42-tubes Years later, the focus became family, a child, and a house. The SX-42 and siblings came with me, but this time, in boxes. After having seen a WW2 vintage Hallicrafters S-20R at a consignment shop a couple of summers ago, I thought how cool it might be to have Dad’s radios electronically and cosmetically restored.

The S-38 and S40 were in a box in my damp basement. While intact, they had a considerable amount of rust. Luckily, I was able to find a gentleman with great electronic and mechanical skills. He brought the S38 back to life, working and looking beautiful. And is working still on the S-40. As for the SX-42, that was upstairs in a box in my son’s closet. Dry and somewhat preserved, but with some corrosion on the control panel. And sadly, that iconic lock knob that switches between main tuning and brandspread tuning, had been lost in the move. I had to find someone who could take this project on.

After an extensive search, I found my man. An engineer with his own business, who was moving into retirement, and shutting his business down. He had restored an SX-42 a few years back, with amazing results. I had to lure him out of retirement! Which I did after a few emails back and forth. And, he was within driving distance! First warning was “do not power the radio back up under any circumstance- you’ll fry the wafers on the bandswitch!” I resisted temptation, as I had read online that these were notorious for failure, usually to some original capacitors that leak over the decades.

After 13 months replacing every capacitor, virtually every resistor, and vacuum tube, the iconic radio was coming back to life, in a great way. The transmission and gears in the tuning was re-lubricated. During the restoration process, a date was found stamped on the chassis of October 25th, 1946. Could it be?

img_7367-02-12-16-06-57-1Hallicrafters had advertised in the Oct, 1946 issue of Radio News that “The first hundred are always the hardest to build.” This, coupled with the fact that none of the chassis circuit had been modified, lead my restorer to believe that my radio was one of the first 100 SX-42’s that Hallicrafters had built!

The front panel was stripped and treated, professionally painted and silkscreened. The cabinet and apron bead blasted, repainted, and clear coated. It came back home with me last month. A month after it turned 70.

halllicrafters-sx-42

As you can see here, the radio looks stunning. And, with all the Hallicrafters Service Bulletin mods implemented, sounds and performs better than I remember. Maybe more importantly, we were able to locate a replacement brake lock knob for the tuning shaft, even with the “Lock” decal and arrow showing to rotate it counterclockwise. It just would not have felt complete without that little knob- and, it works!

halllicrafters-sx-42-frontEngaging a set of what essentially are brake pads, you rotate it once to disengage the main tuning and engage the bandspread tuning. Again, and you’re back to main tuning.

halllicrafters-sx-42-ad

This radio will always remain a truly cherished family heirloom, and will be my son’s someday. Complete with the original owner’s manual, and Darth Vader-like R42 Reproducer (speaker).

halllicrafters-sx-42-front-panel

Hopefully to live on for another 70-plus years, and hear more history along the way.

-Arthur Smith Worcester, MA


Wow–!  Thank you so much for sharing your story with us, Arthur. No doubt, your SX-42 will certainly outlive all of us and will hopefully continue to be passed down through your family. What a wonderful story.

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Update: Hoax Radio transmissions at Melbourne and Avalon airports

The Melbourne Airport (Source: melbourneairport.com.au)

The Melbourne Airport (Source: melbourneairport.com.au)

Many thanks to SWLing Post contributor, Phil Brennan, who writes:

Just a follow up from last week’s story regarding hoax transmissions on airline frequencies at Melbourne airports. An arrest has been made and, if found guilty, the person may face up to 20 years imprisonment. Heavy stuff. Here’s a link to the Aust Federal Police media release:


Man charged following unauthorised radio transmissions at Victorian airports

This is a joint media release with Airservices Australia and the Australian Communications and Media Authority

The Australian Federal Police (AFP) has charged a 19-year-old Rockbank (Victorian) man with serious offences related to the alleged unlawful interference with air traffic control and endangering the safety of aircraft at two Victorian airports.

The arrest follows an AFP-led investigation with the assistance of Airservices Australia, the Australian Communications and Media Authority (ACMA) and Victoria Police.

Between 5 September 2016 and 3 November 2016, there were 16 separate unauthorised radio transmissions at Melbourne Airport and Avalon Airport causing interference with air traffic control.

On 21 November 2016, the AFP arrested a man and subsequently charged him with:

  • four counts of endangering the safety of aircraft contrary to Section 25(2)(b) of the Crimes (Aviation) Act 1991 (Cth); and
  • one count of interference likely to endanger safety or cause loss or damage contrary to Section 194 of the Radiocommunications Act 1992 (Cth)

The man is scheduled to appear before the Melbourne Magistrates Court this afternoon.

The AFP’s head of Crime Operations, acting Assistant Commissioner Chris Sheehan said this arrest demonstrates how law enforcement takes the safety of the airline industry very seriously.

“The current security measures in place for the airline industry are robust, and the traveling public should be reassured we are treating this matter appropriately,” acting Assistant Commissioner Chris Sheehan said.

“These incidents were thoroughly investigated by the AFP with the technical support of Airservices and the ACMA.

“The offences this 19-year-old man faces carry a maximum penalty of up to 20 years imprisonment.”

“The AFP also acknowledges the close working relationship with Qantas and Virgin Australia Group and the assistance provided particularly during the early stages of the investigation,” he said.

Airservices said there is no current threat to the safety and security of the travelling public as a result of these alleged radio transmissions in Victoria.

“Airservices worked closely with the AFP throughout this investigation to ensure the safety and security of the travelling public,” Airservices Southern Operations Manager Steven Clarke said.

“Airservices has appropriate procedures, processes and systems in place to ensure the safety of aviation operations at Melbourne and Avalon airports, and across the country and for the travelling public,” Mr Clarke said.

The ACMA uses a range of technologies and techniques to investigate and locate the sources of unauthorized or interfering transmissions across the radio frequency spectrum.

The ACMA reminds members of the public that making unauthorised transmissions may constitute a serious offence under the Radiocommunications Act 1992 (Cth).

https://www.afp.gov.au/news-media/media-releases/man-charged-following-unauthorised-radio-transmissions-victorian-airports

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Dan takes a critical look at the BBG as government transition commences

View of the Capitol Building from the roof of the Voice of America on 330 Independence Ave., S.W.

View of the Capitol Building from the roof of the Voice of America on 330 Independence Ave., S.W.

SWLing Post readers are likely aware that contributor, Dan Robinson, is the former White House, Congressional and foreign correspondent for the Voice of America.

I’ve just learned that Dan has authored a piece questioning the viability of the BBG as the US presidential transition take place.

Dan’s commentary titled What’s A President-elect To Do . . . With the BBG? appears on the University of Southern California Center on Public Diplomacy site:

http://uscpublicdiplomacy.org/blog/whats-president-elect-dowith-bbg

I encourage you to read his full article and please direct your comments to the original post on the Center on Public Diplomacy website.

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