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USB Audio Recorders?
arunmehta asks: "We're setting up short-range mono FM radio stations in Indian villages. We're currently recommending minidisk recorders to tape and edit (mostly voice) -- does anyone have a better idea? In some stations, we will also implement radio-surfing, so there will be a PC available, and so would like some USB-type connectivity that allows bidirectional transfer of digital audio at speeds higher than real-time. Suggestions for a recorder?"
Why does a little bitty radio station need a computer?
If tits were wings it'd be flying around.
For Mac users, the Griffin Powerwave has the following features:
RCA input and outputs, 1/8" inputs and outputs, built in USB hub and DSP, digital audio amplifier.
Wintel folks will want to check out the Telex device. Edirol UA-1A (44.1 kHz only), Edirol UA-3, GriffiniMic, Opcode DAT-/SonicPort (optical), Onkyo MSE-U33(HB), Onkyo SE-U55 and Roland-ED UA-30.
How many of these have drivers for Linux is anybody's guess.
http://tinyurl.com/4ny52
Why does a local radio station need computer connectivity and minidisks? What on earth is wrong with a cheap AM or shortwave transmitter? And what's wrong with analog audio cassettes? Apart from the power source for the transmitter (and AM and shortwave draw a whole lot less power than FM), this equipment should cost maybe $50 per station, including an old microphone and 2-channel mixing board. And the equipment for such a station can be fixed by anyone, using salvaged parts.
And as for using it to read internet content, how is this village connecting to the internet? If they've got reasonable phones, I guess you could do ftp-by-mail and fetch it overnight by UUCP on a 386. Surely realtime web surfing is an expensive pipe dream in these places. Why on earth is a serious computer with USB at all necessary? In a village where a modern (say, Pentium) computer could be put to much much better use, like public e-mail, research, weather and agricultural data analysis and so forth, setting up a needlessly fancy computerized local radio station is idiocy.
What part of reading news and information that (in a remote village in the developing world) will almost certainly come delayed in the form of text email requires a computer hooked to the radio station?
Can't someone just print stuff out from the village computer (on a reliable, unglamorous, and cheap-to-supply-with-ink dot-matrix printer) and read it on the air on an AM/shortwave station with ten times the range running on a tenth the power of FM? And if they've got to record it for rebroadcast or something, what's wrong with a cheap mono cassette boombox from a backpacker's duffel bag?
My god, have aid agencies gone insane?
Most audio equipment transfers at 1:1, as I'm sure you've noticed. I went shopping for portable audio recording equipment, and ended up with a Roland/Edirol UA-5.
I already had a laptop and plenty of drive space, and the UA-5 has some very nice preamps and ADCs for the price, as well as being quite small and tough. 24/96 for a very reasonable price.
If you do go this route, I'd recommend one of the modified units, or a competitor, that has simulaneous digital outs when recording for backup to another medium, such as DAT.
Minidiscs were out, because of the short record time at higher quality, and the lack of digital outs short of the large home decks. The size/battery life were nice, but the DRM lost them a customer.
There is a lively laptop-taping group at yahoo groups.
You may be interested in the newer HD-based MP3 players.. Nomad Jukebox 3 has a 20-gig drive, and an optical input, and can record to mp3 or wave, as well as an analog in, and supports firewire for fast transfers. I've never used one, so YMMV. It claims 22 hours battery life with a second battery, but I'd take that with an external battery pack (salt not required).
Or for lower-quality, but cheap and portable, look at dictation tape machines, as you mentioned voice content. Many can 'squeal' at higher rates, and you can correct for this by adjusting your sample rate.
There are much higher-end units out there, but they don't seem ideal for rough field conditions, and are overkill for a short-range mono station.
"'Tis great confidence in a friend to tell him your faults, greater to tell him his." --Poor Richard's Almanac
MiniDisc is an excellent format for Amatuer-Semi Pro Use in this capicity. Some of Sony's new portables have usb built in and transfer at least 4x. Most recorders have optical ins, which when combined with the appropriate out allow you to fill a disc at 1x without interaction. I have used MD for years as a theatrical sound designer and I can not say enough good things about it. I build my shows on the pc and burn them to minidisc so that I can edit on the spot.
SD
âoeWho knew something as harmless as willful ignorance could end up having real consequences?â
OK, having spent this much time, I might as well explain why these guys need something more flexible than tape recorders.. These are not pre-programmed stations. There's no centeral person (a DJ or a news producer or whatever) deciding what should go out. There's two-way communication going on here -- the system is a kind of ulta-low-bandwidith web browser.
Extremely poor rural people will use this system to retrieve valuable information -- crop prices, weather reports, what have you -- from the internet. They can't use conventional internet access because there's no rural network infrastructure in India, because these users couldn't afford to access it if there were, and because the info is mostly unavailable in the local language. (India has something like 800 local dialects.) So they're retrieving and translating internet info as people request it.
Maybe this project was more comprehensible to me because of I've read about other south-asian internet access projects, and because I know something of the practical difficulties of translating huge gobs of text. Still, I think the web sites linked to did a pretty good job of explaining what the project is about.
I worked at a radio station in Oxford, UK, for a couple of years. We had Minidisk gear, and we found that all of it (but particularly portable players) was fragile, and prone to breakdown and failure at awkward moments.
We used it because there was nothing better; but in the environment you are talking about, this is definitely not appropriate technology.
Gerv
1. Anyone handy with a knife and a screwdriver--and I mean anyone--can build an AM or shortwave transmitter with miles of range from a few dollars' worth of parts, and can do so for even less with salvaged parts. FM's not forbiddingly complex, but it does need bigger, more precisely measured antennas and bigger transformers, and a lot more juice.
2. Shortwave receivers are expensive in the United States. The receivers used in countries like India--espeically in remote parts of the country that aren't even served by FM--are cheap. Rural India is not the same as suburban Bangalore. As with western China, much of Siberia and much of Africa, where the population is either sparse or very poor, the short range, expensive equipment, and high power requirements of FM don't make much sense.
3. Who said anything about reel-to-reel tape? Who said anything about "professional-quality" audio? This is a community-radio project. They're broadcasting news, weather, and farming reports. For half a century, the world was more than happy with the sound quality of AM broadcasts. People even listened to music on it. Billions of people still do. Plain old consumer-grade cassette tape should be more than adequate for something like this. Minidisc media are expensive. The recorders and playback devices are expensive both to obtain and to repair. And they need repair a whole lot more often than a $20 cassette recorder. Not to mention training involved, and the relative vandalism and theft risks.
Radio journalists worked for many decades with plain cassette recorders, without even Dolby B. I think Indian villagers can, too, especially for broadcasting speech.