Tom says:
>tubes are the weakest and most unreliable link in ANY gear.
Over and above semiconductors? Fine for many parts, but there's been plenty of
semiconductor batches where poor manufacturing factors such as step coverage in
metal and bad injection molding, poor design factors with too high current
densities leading to metal migration, and other QC problems lead to just as bad
a reliability as 8877s can show.....I've even had a tube of 5400 mil temp TTL
parts in ceramic packages where all the lids came off when the tube of parts was
emptied onto the desk.
Of course, it could be argued that 22 years in the semiconductor industry has
made me slightly cynical.......but in the last 20 years of hamming, my major
failure components have been connectors, pilot lamps, and semiconductors (in
order) before tubes.
73
Peter G3RZP
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