| Sendt: 28 Oktober 2006 kl. 07:17 | IP-adresse registreret
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Tak - du har ret "Tadman" det var cobolt som blev svært tilgængeligt og siden steg i pris - fandt nedenstående klip efter lidt research som jeg jo måske skulle have gjort inden jeg spurgte - på den anden side var jeg nok ikke kommet så langt med min anilco-stavemåde  Here's the skinny on the Alnico crisis of 1978. The geographic center
of this situation was the Kolwezi mining region of Zaire. At the time,
Zaire accounted for over 60% of the world’s production of cobalt. In
1977, rebels calling themselves the Front for the National Liberation
of the Congo, invaded from Angola. In May 1978, the cobalt mines in
Kolwezi were taken by the rebels and flooded. Zaire’s cobalt production
was effectively shut down. Considering that most of the remaining
cobalt producers were either behind the iron curtain, or tied up by the
defence industry due to the strategic value of the metal, the net
result was that cobalt was pretty much eliminated from the commercial
market.
Regarding JBL (and I assume the other speaker manufacturers), they were
told by their magnet suppliers that Alnico magnets would not be
available once the current stock was depleted. Greg Timbers (who was at
JBL at the time) stated it wasn’t a matter of cost. Their magnet
suppliers could not provide any new quantity of Alnico magnets. There
was enough stock to continue production for a limited time, but a rush
program was developed to convert the bass drivers to ferrite magnets
since they represented the largest consumption of magnets. In less than
a year, the SFG magnet topology was developed and put into production.
By 1979, France, Belgium and the USA had interceded in the civil war
and the cobalt mines were back in production – albeit at reduced
output. Alnico magnets became available again at higher cost. JBL
continued the manufacture of Alnico compression drivers until 1981,
when it was decided that the economies of switching to ferrite could no
longer be ignored.
__________________ for tiden afspiller jeg meget musik - det lyder godt
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