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09/04/2004 Archived Entry: "shortwave radios"
Strike the Root offers an interesting article which describes the biased news coverage from Iraq, and stressing how important it is for all of us to cultivate alternative news sources. And while the suggestions of Internet sources are excellent, I am embarassed to admit that I have been neglecting a superb channel for alternative news: shortwave radio.
Prior to the Internet, shortwave radio was the means to receive foreign news and opinion. Although it is not as "democratic" as the Internet -- anyone can start a web page, but transmitters and studios cost money -- radio also has the advantage of being harder to control and track than the Internet. (It takes serious equipment to jam a shortwave broadcast, and it's rather difficult for someone outside your house to determine what station you're listening to.) Plus, the Internet can be censored surreptitiously -- remember the denial-of-service attack on Al-Jazeera? -- but radio jamming is pretty obvious.
So I intend to resurrect my old shortwave listening habits. It's a well established hobby with many organizations and magazines -- just Google the phrase "shortwave listening". I'll try to post reception reports of interesting English-language news broadcasts from time to time.
A year or so ago I was asked for advice when buying a shortwave radio. I've lost that posting, but I'll try to reconstruct it here.
The cheapest radios are the ones that have "analog" tuning. Usually these have a "slide-rule" tuning indicator, i.e., a printed scale of frequencies with a moving pointer or indicator that slides over them. Avoid such radios. They're nearly useless for shortwave listening -- it's hard to tune them accurately, nearly impossible to return to a previous frequency, and they usually have cheap electronics with lousy sensitivity and selectivity. (Old '60s and earlier shortwave radios might have good electronics, but their analog tuning is still hard to use.)
Digital tuning is the first feature you should look for. At the bottom end this may only cost you a premium of only $10 or $20. We have a Grundig Traveller II Digital portable that cost Cdn$45 on clearance. Other features that it lacks and you might look for are a numeric keypad for frequency entry, or a tuning knob. (The Traveller II Digital has only "up" and "down" buttons, and it can take a while to tune between stations!)
Selectivity is the next magic word. This refers to a radio's ability to discriminate between two stations very close in frequency. With cheap radios you'll hear both at one time, possibly with an annoying whine as they interfere with each other. A better radio will have selectable "bandwidth" -- either "wide" vs. "narrow", or in the top end receivers, an assortment of selectable filters. (Selectivity is measured in kiloHertz, kHz. For shortwave broadcasts, 6 kHz would be as narrow as you want, and 15 kHz reasonably wide.)
Sensitivity refers to the radio's ability to pick up weak stations. If you're trying to pick up Radio Sri Lanka, you might want an extra-sensitive receiver, but most broadcasters use a fair amount of power....and the best way to improve your weak-signal reception is to put up a better antenna.
Single sideband (SSB) reception is, frankly, optional. Shortwave broadcasters use amplitude modulation (AM), which all radios will receive. Radio amateurs, the military, and international aviation use SSB, so if you want to venture out into that aspect of shortwave listening, you'll need SSB.
Synchronous detection gives -- I am told -- greatly improved reception of AM signals. None of my radios has this feature, so I can't give a firsthand review; but from my knowledge of radio theory and the reviews I've read, I'm determined to get this in my next receiver. (One reason I don't have this now is that it's rarely included in amateur radio transceivers, and that's what I currently use for shortwave listening. Only dedicated shortwave receivers have synchronous detection.)
DXing.com has a useful web page that explains these features and more. The Ontario DX Association offers useful (if slightly dated) recommendations for what to buy. Before buying it's worth checking out the product reviews at eHam.net. Radio Netherlands also offers reviews and recommendations. ("DX", by the way, is an abbreviation for "distance" and usually refers to long-distance radio reception; thus, "DXing" is the pastime.)
I'll be fishing the Internet, looking for more resources (like station guides and antenna suggestions). The Internet is the shortwave listener's friend! Try a Google search for "english language shortwave broadcasts".
brad