Category Archives: Articles

Wired: Listen to a Solar Flare Drown Out Radio Communications on Earth

(Photo: NASA via Wired)

(Photo: NASA via Wired)

(Source: Wired)

Over the weekend, a tiny spot on the sun erupted into a moderately sized solar flare that was particularly loud in radio waves. With the sound of a roaring wave, it completely drowned out radio communication all over the Earth between 28 MHz and 21.1 MHz.

The recording [found on this page] comes from either a short wave radio station or a Ham radio transmission, said amateur radio astronomer Thomas Ashcraft, who works with NASA’s Radio JOVE project. It’s interesting to hear the voices get “swallowed up as the solar wave passes through,” he added in an e-mail to Wired.[]

Read the full article on Wired.

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Making A Transistor Radio by George Dobbs

A sample illustration from "How To Build a Transistor Radio"

A sample illustration from “Making a Transistor Radio”

Those of you who are ham radio operators (especially QRPers) are familiar with the name George Dobbs (G3RJV). In 1972, Reverend Dobbs wrote a book called, Making A Transistor Radio and now it’s available online.

Making A Transistor Radio is a clear, simple, step-by-step guide to building your own transistor radio. In each stage of the process you’re rewarded with a working radio. In addition, you’ll learn about all of the stages of a working receiver.

Perhaps what I love best about this book–besides the fact that is resembles the mountains of electronics books I poured through in my youth–are the illustrations.  Each illustration describes exactly how each component of the radio should be built, leaving nothing to be pondered.

If you’ve ever wanted to build your own radio, from scratch, this is a great place to start.

Thanks, Eric, for sending this link!

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Mark’s studio version of Firedrake

(Photo: Satdirectory.com)

(Photo: Satdirectory.com)

As I suspected, the unidentified broadcast I recently posted was the Chinese jamming service, Firedrake.  Thanks to all who confirmed.

Mark Fahey even commented with a link to an article explaining how he made a studio recording of Firedrake from Chinasat 6B. Read Mark’s article here.

Mark also has the full 60 minute studio copy of Firedrake available as a 90MB MP3 file.

 

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Mike’s home brewed amplified antenna

Active Ferrite Rod Antenna (Photo: ON2NLT)

Active Ferrite Rod Antenna (Photo: ON2NLT)

In my recent post, The truth about portable amplified shortwave antennas, I argue that small, portable amplified antennas are, by and large, ineffective. The post comments are interesting, however; many readers agree, and some tout the Sony ANT-LP1 as worthy, but Mike made the following comment about his amplified antenna:

The one active antenna that I have been pleased with is one I built myself.  The design was by ON2NLT and uses a ferrite rod, so it is somewhat directional.  Rotating the unit (it is very compact) often allows nulling out noise or interference.  You have to be careful not to crank up the gain too much though, or you will amplify the noise floor.  The link is here

http://www.kolumbus.fi/juha.niinikoski/Ferrite_antenna/Ferrite_antenna.htm

Looks like a fairly simple project.  Thanks, Mike!

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Dave’s FM station empire

FMMegaplexDave Schmarder (N2DS) enjoys making radios and featuring them on his website, http://makearadio.com. What you may not know is that he also runs his own FM stations empire…and you can too:

I thought your visitors might be interested in my FM stations empire. I bought a bunch of mp3 players with built in fm transmitters that are usually used in a car and adapted them for home use. They all cost me under $4 each, plus a TF card for a couple bucks for each music transmitter.

At the moment I have 8 transmitters running, mostly with usb sticks looping music, but also a transmitter hooked to my tv cable box and another one to my internet radio.

This allows me to be anywhere in my little house and listen to these audio sources using a small Tecsun FM radio. During the summer I could sit on my porch and listen without dragging my radios or iPad outside.

Perhaps some of your visitors might be interested in having their own fm radio megaplex. Here is the link: http://www.n2ds.com/musiccenter/musiccenter.htm

73, Dave
N2DS

Thanks, Dave!

I’ve often thought of broadcasting 1930’s and 40’s music over a micro shortwave transmitter in my house. I would love to know if any readers have done this. Admittedly, it would take a pretty committed shortwave radio geek. Anyone? Anyone?

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The truth about portable amplified shortwave antennas

In the past week, I have had no less than 3 email inquiries from readers regarding which amplified antenna to purchase for their portable shortwave radio.  My short answer? None.

In my opinion, there’s one fatal flaw with amplified antennas: they amplify noise just as much as they do the signal you wish to hear.

The Sony AN-LP1 is the best amplified antenna I've ever used, but that's not saying a lot.The only portable amplified antenna I’ve had any results with is the Sony AN-LP1 (now only available in Japan), and I attribute this success mainly to the fact that a suction cup, mounted at the top of the loop, allows it to be mounted on a window. Even then, results are often only marginally better than with the telescopic whip.

There may have been a time when portable amplified antennas made sense–a time prior to noisy AC adapters, flat screen TVs, and other consumer electronics which spew RFI (Radio Frequency Interference), polluting our shortwave bands. Today, however, you’ll be disappointed with the results of one of these, particularly if you travel–turning on the amplified antenna in a hotel room will increase the noise you hear two-fold, while weak broadcasters will remain lost in the static.

RollUpAntennaReelSangean

The Sangean ANT-60 is inexpensive and vesatile

So what can you do to improve the performance of your portable while traveling or at home? I’m still a fan of the roll-up antenna; like the Sangean ANT-60.  They’re inexpensive ($12 US), packable, and versatile–the clip on the end of the reel allows the antenna wire to be clipped to curtains and blinds. Place it near a window, or even hang it outside. Antennas love being outside–just take it down when not in use.

In lieu of buying a roll-up antenna, you could simply attach an alligator clip to the end of a 20′ (6 meters) length of wire.  The alligator clip can then attach to the end of your telescopic antenna, and you now have the same properties of a roll-up antenna for pennies. This is possibly the most cost-effective way to improve the performance of your portable shortwave radio. One note of caution: don’t get too generous with the length of your antenna wire. Some portable radios lack a robust front-end and a wire that’s too long could actually overload the receiver. Some Grundig G5’s were even sensitive to static discharges over a wire antenna. If uncertain, I would not exceed 20 feet in length (6 meters).

An alligator clip offers serious bang-for buck--especially if you already have the parts lying around

An alligator clip offers serious bang-for buck–especially if you already have the parts lying around!

I’ll never forget:  one of the first email questions I received on SWLing.com was from a fellow listener in Washington state who wanted to hear stations better on his Sony portable. I suggested the alligator clip/antenna wire. He wrote back enthusiastically, “This is the most cost-effective improvement I have ever made to anything!” He was so encouraged with the performance improvement, he invested in a tabletop and a proper outdoor antenna with grounding.

So, I urge you to try a roll-up antenna or the alligator clip antenna before you waste money on a portable amplified antenna.  Just my two cents.

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Vlado’s thrift store find: A Sony ICF-2010

The Sony ICF-2010

Vlado’s Sony ICF-2010 (Click to enlarge)

While visiting my friend, Vlado, this weekend, he showed me his thrift store find: a Sony ICF-2010 in very good condition`. The ‘2010 is a well-known portable amongst serious DXers, and is highly sought-after. Since this radio has not been in production for many years, used models routinely sell for a price in excess of $200 US. Parts radios sell for $50 US or more.

We suspect that the previous owner thought it stopped working. You see, when Vlado plugged in the AC power adapter, nothing happened.

But take note: there is a quirk, at least with some ICF-2010s–they will not power up, even with the AC adapter plugged in, if you don’t have AA batteries installed. Indeed, two AA cells are required for either DC or 120 VAC operation. Once Vlad put AAs in, the radio came to life.

How much did  he pay for his Sony ICF-2010? Five dollars.

Paint me envious!

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