Category Archives: News

Review of the SSTRAN AMT3000 AM transmitter kit

Regular SWLing Post readers know that I’m a sucker for vintage radios––especially those of the WWII era. Indeed, I’m pretty much a fan of anything from the 1930s and 40s. I love the technology of that era and have an affinity for the culture and history, especially film and music.

Last year, I acquired a beautiful Scott Marine Radio Model SLR-M––a receiver that quickly became the centerpiece of my modest vintage radio collection.

Scottie (yep, I call her Scottie) produces beautiful, rich audio from her internal speaker. It’s truly an amazing piece of over-engineered technology that still sounds this good after 70 years.

Edythe Wright

Only a week or so after plugging Scottie into an antenna, my wife and I picked up a $1 CD at a church yard sale. The CD featured big band music from the late 30s/early 40s. Though we already had much of the music on the CD, we bought it anyway to keep in our car. One beautiful fall day, I was driving down a rural road and had the CD playing when a Tommy Dorsey recording of “The Music Goes Round And Round” with Edythe Wright on vocals, began playing. It had been ages since I heard this song…I then wondered how many GIs might have heard this song during WWII via GI Jive or the Armed Forces Radio Network. Perhaps they heard it on the Navy version of my Scott Marine radio, the Navy REH?

It was then I decided to finally pull the trigger and order a proper low-power AM transmitter for our home––something with which I could broadcast period music via my vintage gear.

There are a number of AM transmitters on the market, but the one that always stands out from the crowd is the SSTRAN AMT3000. My buddy, The Professor, has one and uses it to consume much of his digital audio content including podcasts and Internet radio stations. He sang the AMT3000’s praises, and I trust the Prof; he’s something of a medium wave guru.

Thing is, the AMT3000 only ships as a kit. In the past, this had stopped me from ordering the transmitter as I figured it was more than my beginner kit-building skills could manage. But after building David Cripe’s Ozark Patrol regenerative receiver, and loving the experience, I felt confident enough to make the order.

And, boy, am I glad I did!

The SSTRAN AMT3000 kit

The kit arrived within a few days of ordering it. Upon unboxing it, I felt like I had gotten my money’s worth, as it was packaged carefully in a quality box: components were clearly labelled in their own poly bags, the board was clearly marked with component numbers and the assembly/instruction manual was in a plastic binder, all clear and straightforward.

SSTRAN suggests taking your time building the kit, as there are a lot of components to solder, and you risk making mistakes that aren’t necessarily easy to remedy if you rush through the process. I tried to follow this advice––well, I intended to follow this advice. Thing is, I find it very difficult to put down a kit once I’m in the zone, so I zipped along a bit more quickly than I intended.

But it helped that SSTRAN took out a lot of the head-scratching and guesswork; the process couldn’t have been more smooth. I carefully checked and double-checked each component and marked it off the assembly list. First, you install all of the resistors, then capacitors, and on to other components. Other than having to hunt for some of the component locations on the board, it really was quite simple.

I started building the kit on a Friday afternoon and actually finished it the following Saturday morning. Much to my delight, after performing the tuning procedure, the transmitter worked on the first go. Whew!

Powerful (low power) broadcasting

The AMT3000 can be configured to work with the supplied simple wire antenna, which will essentially broadcast AM to radios throughout your home, or it can be configured for a Part 15 compliant outdoor base-loaded vertical antenna which will extend your range up to 3/4 of a mile, should your shack be down the road or in an outbuilding.

For the moment, I have my transmitter set up for in-house broadcasting only. If I ever want to build the base-loaded vertical, I only need to make a simple modification to the board to do so.

The supplied manual does a great job of explaining the best ways to maximize your signal, reduce any electrical hum and tweak your audio fidelity.

I’ve been using the AMT3000 nearly every day since I finished building it in mid-November. It seems to have a 100% duty cycle, does not overheat, and has no drift.

It produces high fidelity audio with a flat frequency response––and of course, with modulation and compression controls, you can tailor the audio to your particular taste.

Result? It sounds amazing piping WWII-era tunes through my Scott Marine SLR-M, Hallicrafters SX-24, and SX-99 and my Hammarlund SP-600.

As a bonus, I can hook my shortwave receivers up to the AMT3000 and listen to received audio via other radios throughout my house. Many times, I’ve listened to live broadcasts of ERT Open on 9,420 kHz via my kitchen AM radio…Very cool!

I also hook the AMT3000 up to my shack PC and stream my favorite internet radio station: the UK 1940s Radio Station via TuneIn radio. Absolutely brilliant!

I set my transmitter to 1410 kHz, and have left it there. You’ll need to do a medium wave (AM) survey to find the clearest spot on your AM dial. I’m sure results will vary, depending on the level of medium wave broadcast activity in your area.

Here’s what my Scott Marine SLR-M sounds like playing “March of the Toys” by Tommy Dorsey and his Orchestra via the SSTRAN AMT3000 (note that this was recorded with just an iPhone, so audio fidelity is somewhat lacking):

Conclusion

If you’re looking for a high-quality, low-power legal AM transmitter, I highly recommend the SSTRAN AMT3000. Even if you’re a novice kit builder, with time and patience, you can successfully construct the AMT3000, too. If I did it, you certainly can!

If you’d prefer buying a pre-assembled AMT3000, they do occasionally turn up on eBay. Click here to search.

As for me, I’m happy to have achieved my modest goal of being able to broadcast 1930s and 1940s music to vintage radios of the same era.

SSTRAN sells the AMT3000 directly on their website. Click here to view.

SSTRAN AMT3000 Models and Prices (via SSTRAN)

AMT3000
10 kHz channel spacing for use inside North and South America. Includes enclosure and 120 Volt AC Adapter. The single surface-mount IC is pre-soldered on the board.
Price: $92.95

AMT3000-9K
9 kHz channel spacing for use outside North and South America. Includes enclosure and 120 Volt AC Adapter. The single surface-mount IC is pre-soldered on the board. *
Price: $92.95

AMT3000-9KNT
Same as AMT3000-9KSM, except the US-standard 120 Volt AC Adapter is not included. **
Price: $88.95

Dan’s WWVH QSL cards

When held captive, radio provides escape

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Many thanks to Any Sennitt who shares a link to this article by Telegraph journalist, Colin Freeman.

(Source: The Telegraph via Andy Sennitt)

Along with the glaciers of the Arctic and the sand dunes of the Sahara, northern Somalia is one of the loneliest, most godforsaken places I’ve ever visited as a foreign correspondent. You can wander its Arizona-like landscape for days without seeing another soul, and when I was held hostage there in 2008, I could see why so many British troops posted to Somalia after the Second World War committed suicide through loneliness.

That I did not succumb to the same urge is thanks to many factors – one being the good cheer of the photographer held captive alongside me, another being the Telegraph’s heroic efforts in securing our release.

But during the six weeks we spent held at gunpoint in a cave, one thing that stemmed the despair was the tiny, battery-operated radio that our kidnappers sometimes lent us. On the short wave channel we could get a faint BBC World Service signal, and while it was often fuzzy as it bounced round the cave’s walls, it was better than yet another game on our chess set made from cigarette foil.

So I’m pleased to hear that this lifeline is now being extended to inmates of another, much larger prison – the 25 million citizens of North Korea, who are denied access to any outside media by their leader, Kim Jong-un. As the Telegraph disclosed on Thursday, the World Service is to plan a new North Korea channel, giving the country’s brain-washed citizens a much-needed alternative to the relentless propaganda of the world’s last Stalinist regime.

[Continue reading at The Telegraph…]

X-class solar flare causes radio blackout

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(Image source: Screen capture from NASA video)

(Source: Discovery News)

The sun has erupted with its first X-class solar flare of 2015, a not-so-subtle reminder that it can still muster the energy required to generate the most powerful class of solar explosion.

The magnetic eruption occurred yesterday (Wednesday) at 12:22 p.m. ET (16:22 UT), lighting up a huge area in the lower solar corona (the sun’s magnetically dominated ‘atmosphere’). Shortly after the huge eruption, that measured X2 on the scale of flare energy, Spaceweather.com reports a radio blackout was detected over large swathes of the globe, including much of the Americas.

“The X-flare scrambled the ionosphere thoroughly so that no decametric radio signals were supported in my part of the world,” said amateur radio astronomer Thomas Ashcraft. “The ionosphere started to reform after about fifteen minutes when stations began to reappear. (The stuff visible during the blackout was my own observatory electricity. Nothing exterior.)”

Based in New Mexico, Ashcraft reports that the blackout was most obvious in the frequency range of 15 MHz to 26 MHz.

[Continue reading at Discovery News…]

Good news? There may be some HF band openings in the wake of this flare. We shall see.

Fans of “The Rockpile” and “Jazz from the Left” can now listen online

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Raoul van Hall (Source: Ameristream Live)

After Global 24 went off the air, several SWLing Post readers commented that they were going to miss hearing music programs like Jazz from the Left and The Rockpile.

Fortunately, Raoul van Hall, who hosts and produces both programs, noticed your comments . Yesterday, he commented with good news:

“For those of you who would still like to hear The Rockpile or Jazz from the Left, you can follow these links to hear both programs, whenever and wherever you’d like:

http://ameristreamlive.com/the-rockpile/

http://ameristreamlive.com/jazz-from-the-left/

I’ve exchanged a few emails with several SW stations to maybe put RP or JFTL back on shortwave. Different time and frequency. We’ll see. I’d have to lease the airtime and hopefully get at least one sponsor and some listener contributions. I like the idea of broadcasting on shortwave. After all of these years on AM and FM.

I used to love listening to music on shortwave, when I was younger. When there was some music on SW. There’s something about hearing the music fade in and out on the signal that’s magical to me. I first fell in love with radio listening to shortwave.

Plus I like being able to play lots of music that’s not heard anywhere on US FM.

If I decide to do it, I’ll make sure it’s on a smoking signal and at the right times.

Naturally, I’d welcome any of your thoughts or suggestions.

Raoul”

I couldn’t agree with you more about the magic of hearing music over shortwave.

Raoul, keep in touch and I will post any updates you provide regarding potential shortwave broadcasts. Thanks for making your programs available via Ameristream Live.

RAI may face reform

Richard’s CBC Radio-Canada QSL and interview with RCI

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Many thanks to SWLing Post and SRAA contributor, Richard Langley, who writes:

“[C]oncerning the RCI anniversary, attached are scans of a QSL card from the CBC International Service for reception on 20 April 1964 when I was in high school. That was on the Knight-Kit Span Master regenerative receiver I had built the previous Christmas.”

“About 50 years later (in 2012, actually), I did an interview with RCI’s Victor Nerenberg on GPS and the ionosphere, which appeared on the RCI program “The Link.”

It’s still on their website:
http://www.rcinet.ca/english/archives/program/the-link/home/date/27-01-2012/
(about 15 minutes in)
and
http://www.rcinet.ca/english/archives/program/the-link/archives/episode/09-10_2012-01-30-the-link-friday-january-27-2012/

The RCI site also is featuring some information related to the 70th anniversary:
www.rcinet.ca/rci70-en/

And, lastly, there’s also some interesting stuff in the CBC’s Digital Archives under
http://www.cbc.ca/archives/categories/arts-entertainment/media/radio-canada-international-canadas-voice-to-the-world/broadcasting-to-the-world.html
There was also an episode of the CBC Rewind archives program on RCI:
http://www.cbc.ca/player/Radio/Rewind/2011/ID/2167995222/