Historically, SWL's have used audio tape for preserving their catches. I have a collection of audio cassette tape that goes back to 1975! Yes, that is a whopping 25 years plus on aging magnetic tape. I know I am not alone in this fear - tape does not last forever. What does?
I have taken steps to preserve some of the quality and immediacy of these early recordings. I have recorded them again onto cassette audio tape!
Let's back up half a step shall we. It was the first few monthes of getting my first PC and realising that I could record audio on to the hard drive. Okay so my first PC was not a 386, it was a 300 Mhz Pentium. I have worked with computers since the early days - just had no desire to have one at home. It was, in fact, some time before PC's and soundcards became good enough to record live audio glitch free. Well, the time has come. This PC solution has served me well where bringing old tapes back to life and saving them from an eternity of hiss and dropouts.
Picture this - you have 30 years worth of cassette tape recordings of radio stations that no longer exist, odd reception phenomenon, pirate radio, historically significant news broadcasts and so on. Now 30 years ago you may or may not have thought too much about the future. I did... and I didn't. Oddly and refreshingly, my first tape, Tape-One if you would, is the only bad one in the bunch. Why? I did not record it at the right level. I had a Transonic Executive office cassette recorder that my dad left behind when he abandoned his family. This was put to good use.
The seventies were a very exciting time for the Short wave listening enthusiast and Amateur radio operator and the like. Think Cold War, Communism, global tension, a time of change that few other times on the latter part of the 20th century. Goal - get as much of this action on tape! And I did...
Fast forward to 2001. First question: where did the time go? Next question: Where are my tapes!? Okay, they are safely in a box on the closet shelf where they have been for years as far away from magnetic fields as possible. I have got a good PC and a good sound card. With a couple of good sound utilities I have managed to dump most of the serviceable stuff from quarter century old media onto the hard drive. Gosh that makes me sound old - quarter century old! Truth is, I am quite young - earlyish forties.
Okay, this is great! The past has been rescued so, what about the present and future? That trusty old Transonic Executive tape deck, like a dog past its day has dissolved into the crusty recesses of time. Seriously folks, it seemed to do just that. After 30 years, this old beast just seemed to rot away. Rust and rotting rubber and primordial ooze consumed it, pretty much beyond repair. I do have a heavy duty JVC direct drive studio grade cassette deck with Dolby B, C, D, E and F, as well as DBX, but I have little interest in staying with this archaic technology just now.
Enter the Sony Mini-Disc - Like a miniature read writeable compact disc, the Sony MD can record up to 320 minutes of digital audio without interuption. These discs can be used over and over again. How long do they last? Good question. This is new technology. I do not think that there is a definitive answer. If there is and I have missed it, please post the response below. Let us assume, at least for the duration of this article, that Sony MD's audio lasts forever! Yeaaaa!
From minidisc.org, the definitive guide to MDing -
"Sony claims in their Magneto Optical FAQs that data may be stored with magneto optical technology for more than thirty years without loss or degradation. Once written to the disk, data are safe from the magnetic fields and heat found in normal environments. However, strong magnets placed directly against the MD can destroy data, as evidenced by informal experiments conducted by users. In contrast, a modern (ca. 1999) 'silver' pressed CD from a glass master is reckoned to last around 50 years or so from a chemical point of view. However a problem was found with the chemistry comprising early CD's (of around seven years and older) which caused degradation within a decade."
Hmmmm. 7 years to 30 years. I had better keep my eye on this!