Raspberry Pi 2 API for the SDRplay RSP

DSCF5072

Many thanks to Jon Hudson at SDRplay who notified me that they have released a Raspberry Pi 2 API for the SDRplay RSP receiver. Note that the API is a “pre-release” version and you’ll need to reference the included Linux installation notes.

If you have the RSP and a Rasberry Pi 2, you might consider trying the new software. The SDRplay development team are eager to hear feedback.

Click here to download.

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Shortwave Radio Recordings: Radio Romania International

RRI

For your listening pleasure: 1.5 hours of Radio Romania International, starting with RRI’s English language service.

This recording was made on May 25, 2015 starting around 00:00 UTC on 9730 kHz. I used the TitanSDR Pro software defined receiver and skyloop external antenna to make this off-air recording.  In truth, this is one of the few remaining broadcasters that targets eastern North America; even a simple portable radio would have sufficed.

Click here to download the full recording as an MP3, or simply listen via the embedded player below:

Posted in Broadcasters, News, Recordings, Shortwave Radio, What's On Shortwave | Tagged , , , | 1 Comment

Honoring Memorial Day: The White Cliffs of Dover

Dame Vera Lynn

Dame Vera Lynn

Today is Memorial Day, and I’m feeling humbly grateful to all of those who paid the ultimate sacrifice for their country. Since I’ve been reading a lot of WWII history lately, I’ve also been playing a lot of WWII-era music here in my sanctuary to all things radio.

Few songs sum up the yearning sentiment of World War II better than Vera Lynn’s 1942 rendition of “The White Cliffs of Dover.” It’s an iconic song, one that helped British soldiers see beyond the war while mourning its painful toll. It was written in 1941 when England was taking heavy casualties, just before American allies joined the effort.

Scott-Marine-Radio-SLR-M

This morning, seeking something with a little authenticity, I played “The White Cliffs of Dover” though my SStran AM transmitter, and listened to it through “Scottie,” my WWII-era Scott Marine radio (above). I made this recording by placing my Zoom H2N recorder directly in front of the Scott’s built-in monitor speaker.

So here you go: a little radio tribute to all of those who fell–on both sides–of that infamous second world war.

And thanks to all who serve and have served in the name of “peace ever after.”

Click here to download the recording as an MP3, or simply listen below:

Posted in AM, Articles, Mediumwave, News, Radio History, Radios, Shortwave Radio | Tagged , , , , , | 6 Comments

Jack Barsky: KGB spy who relied on numbers stations

JckBarsky

Many thanks to SWLing Post reader, Anthony, for forwarding this CBS/60 Minutes video: an interview with former KGB spy, Jack Barsky. During the interview, Barsky mentions that he received encrypted KGB “radiograms” via a numbers station he believed to be in Cuba. He admitted that the messages could take an hour to copy, then an additional three hours to decode. This is a fascinating story–well worth watching.

Here is the intro via 60 Minutes:

“Tonight, we’re going to tell you a story you’ve probably never heard before because only a few people outside the FBI know anything about it. It’s a spy story unlike any other and if you think your life is complicated, wait till you hear about Jack Barsky’s, who led three of them simultaneously. One as a husband and father, two as a computer programmer and administrator at some top American corporations and three as a KGB agent spying on America during the last decade of the Cold War.

The FBI did finally apprehend him in Pennsylvania but it was long after the Soviet Union had crumbled. What makes Jack Barsky’s story even more remarkable is he’s never spent a night in jail, the Russians declared him dead a long time ago, he’s living a quiet life in upstate New York and has worked in important and sensitive jobs. He’s now free to tell his story…as honestly as a former spy ever can.”

Click here to view the video via CBS online, or you can simply watch via the the embedded players below:

Part 1

Part 2

Posted in Interviews, News, Numbers Stations, Shortwave Radio, Videos | Tagged , , , , , , , | 3 Comments

Dave says not all Jameco power supplies are linear and regulated

Note that not all power supplies are listed as "regulated linear"

Note that not all power supplies are listed as “regulated linear”

Many thanks to SWLing Post contributor, Dave Zantow (N9EWO), who replies to a post published yesterday regarding some of Jameco linear power supplies. Dave writes:

“A bit of a caveat on Jameco’s these so called Linear power supplies. This is based from my own experiences so is not fiction.

Bottom of this page : http://www.jameco.com/Jameco/catalogs/c151/P92.pdf

Over the years some of (but not all) these Jameco linear regulated power supplies are no longer clean for radio use.

Without changing the model number or description of the product, they have made changes with some (or much of ??) this “Linear Regulated” adapter line. Indeed they are still using a good old power transformer, but when it comes to the regulator part of the adapter, they have gone to switching type regulator device. So it produces a nice strong whine on a radio receiver just as a full fledged switching supply.

I had purchased a number of these so called linear supplies (sorry I no longer have the exact model number noted that I ordered) and experienced awful interference with any radio receiver. So I cracked open one of these to see what was up here and sure enough it was using a MC34063A inverting switching regulator .

Called Jameco and they flat out denied that they were using any switching devices in this Regulated LINEAR Jameco ReliaPro adapter. So I then sent a nasty gram email to the CEO of Jameco. I received an email back (was from the CEO too) and after some research they FINALLY did admit a change was made in some of the product line to use of a switching regulator . But he strongly made the point they would continue to still market these adapters as totally linear (yeah right ….nice guys).

I must add here that it does (or did not) NOT affect the entire line of these linear regulated adapters. About a year ago I ordered more (already had a few before) of the 12 volt 1 AMP model 170245 , and these are (or were anyway) totally clean and are excellent.

Also note that Jameco purchases up surplus “linear regulated” adapters from time to time. This 6 volt 500 ma one here is an example and is (or was anyway) nice clean one and uses no switching regulators. Our 2 tested samples of this adapter from about 5 years ago used a nice 7806 analog regulator. Perfect for use with many SW portables, (including the Sony ICF-SW7600GR with a plug change). But a warning again from experience , they are all subject to changes without any warning (and this one may have changed too for all we know ??)

They appear to stick the ReliaPro name as the manufacture on all adapters (if it was made by Jameco or not)

So Caveat Emptor.”

Duly noted, Dave! I’ve also noted that not all of the power supplies on their linear power supply page are listed as being a linear supply (see screen grab at top of page).

I may contact Jameco about this too and see if they can adjust their search results to properly reflect a selection of regulated linear supplies.

Posted in Articles, News | Tagged , , , , , , , | 2 Comments

How to replace a noisy wall power supply

JamecoWallPowerSupplyRegarding noisy switching power supplies, SWLing Post reader, Dan Lewis, comments:

“Google the following: “Jameco linear wall transformer”, and you’ll find a suitable non-switching replacement.

Jameco still has a number of linear transformers in their catalog at reasonable prices. I haven’t bought anything from them in many years but when I dealt with them frequently a number of years back they were always reputable.”

Many thanks for your suggestion, Dan! Jameco is a reliable company and I’ve also been a long-time customer. If you know how to pick the proper power supply for your radio (or any other electronic device) click here to view a list of regulated linear supplies on Jameco’s website. [Also note this follow-up post.]Otherwise, keep reading…

How to find a replacement AC adapter/power supply

When you purchase a replacement power supply, you must make sure that several properties match that of the device it will power, else you could cause damage.

There are four properties you need to match: voltage, rated current, polarity and tip size.

Voltage

Most consumer electronics are powered by and rated for 4.5, 5, 9, 12, or 13.8 volts DC. Of course, there are exceptions. It is important that you match the required voltage exactly. Most radios and electronic devices display their required voltage and voltage tolerance on the unit itself, on the supplied switching power supply, and/or in the owner’s manual.

Rated Current

Like voltage, rated current is usually displayed somewhere on the device, existing power supply or in the owner’s manual. Current is usually indicated in amps (A) or milliamps (mA). Unlike voltage, rated current on your power supply does not have to match the device exactly. You simply need to make sure the power supply meets or exceeds your radio’s required current.

For example, if your radio requires 800 mA (or .8 A) and you find a power supply rated for 500 mA, you should not use it. If you find a power supply rated for 2 amps (or 2000 mA), it exceeds the 800 mA rating, so you’re good to go!

Unlike voltage, your electronic device or radio will only draw the amount of current it needs from the power supply.

Polarity

Click here to read more about tip polarity. (Source: WikiPedia)

Click here to read more about tip polarity. (Source: WikiPedia)

You’ll need to determine if your radio requires a plug with a positive or negative tip (a.k.a. center conductor).

Fortunately, manufacturers have long used standard symbols to make polarity obvious (see image).

You’ll typically find a polarity symbol printed on the back of your radio, near the plug-in point, in the owner’s manual or on the back of the existing wall adapter.

Note: Be very careful matching polarity! Some radios and electronic devices are not properly protected against reverse polarity; damaged can occur immediately after supplying voltage with incorrect polarity.

TJamecoWallPowerSupplyip/plug size

You need to make sure that the inner diameter and outer diameter of a replacement wall adapter will match that of your existing adapter.

This can be the most difficult property to match.

Occasionally, radio manufacturers will actually specify the tip size in their owner’s manual, spec sheets, or on the product page of their website. I’ve even had luck calling manufacturers and asking a technician for the plug size.

ACAdapterTip

Specification sheets will typically indicate plug dimensions with an illustration.

Otherwise, you can always measure the existing power supply tip (both inner and outer dimensions) using calipers.

Once you have those dimensions, finding the appropriate replacement power supply is quite easy. Indeed, companies like Jameco provide specification sheets (click here for an example) that indicate dimensions for each power supply they sell.

Once you’ve matched the voltage, rated current, polarity and tip size, you can purchase a regulated linear power supply with confidence!

Keep in mind: there are most likely other devices in your home with noisy switching power supplies that could be causing radio interference. Check out my noise trouble shooting section of this article to help identify local sources of radio noise.

Update: check out this follow-up post regarding Jameco power supplies–not all are truly linear regulated.

Posted in AM, Articles, How To, News, Portable Radio, Radios, Shortwave Radio, Tutorials | Tagged , , , , , , , , , | 5 Comments

National Radio Quiet Zone featured in BBC Radio 4 series

GreenBankTelescope

Many thanks to SWLing Post reader, David Freeborough, who shares this brilliant, in-depth radio documentary featured on the BBC News and BBC Radio 4.

This BBC News Magazine article introduces the documentary:

“Anyone driving west from Washington DC towards the Allegheny Mountains will arrive before long in a vast area without mobile phone signals. This is the National Radio Quiet Zone – 13,000 square miles (34,000 sq km) of radio silence. What is it for and how long will it survive?

As we drive into the Allegheny Mountains the car radio fades to static. I glance at my mobile phone but the signal has disappeared.

Ahead of us a dazzling white saucer looms above the wooded terrain of West Virginia, getting bigger and bigger with every mile. It’s the planet’s largest land-based movable object – the Robert C Byrd Green Bank Telescope (GBT) – 2.3 acres in surface area, and taller than the Statue of Liberty.

But it needs electrical peace and quiet to do its job.”

[Continue reading…]

The story continues on the BBC News site, but I would encourage you to listen to the five part radio documentary series on BBC Radio 4 first. Green Bank, WV, is certainly one part of the planet where a shortwave radio listener would be quite happy: residents have virtually no radio interference or obnoxious electrical noises that plague the rest of the modern world.

telescopes-1911The radio documentary can be streamed on the Radio 4 website.  I’ve included links to each episode below. As far as I can tell, there are no expiration dates on the Radio 4 streams:

My wife and I have camped near the NROA site in Green Bank–it’s a beautiful part of the world. I’m certainly long overdue to return!

Again, David, many thanks for sharing this!

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