While looking at a replacement woofer for a friend of mine, I noticed its huge magnet and metal encasing shield. Ah yes, I thought, the magnetic shield that was all the rage a few years ago.
That shield was needed to protect cathode ray tubes from TV’s which use magnetic steering to position their controlling electron beams. Those electron beams had to be pointed at precise locations to light up different colored phosphors.
Ray tubes! What Buck Rogers technology was this?
Of course, I am referring to the old style television tube known as the CRT: small glowing tubes that grew in color range and size over their 75-year reign. The largest commercially available model was about 45 inches and weighed several hundred pounds. Larger TVs were technically possible but not marketable as the depth, weight, and cost made them difficult to sell. A 50-inch TV would require a 38-inch picture tube and even larger casing, making it near impossible for the TV to fit inside a standard door (let alone be hefted by mere mortals).
CRT televisions were finally phased out as late as the 2000s and replaced by plasmas, LCDs, OLEDs, LEDs, etc. The newer technologies are insensitive to magnetic fields, and thus, the need for magnetically shielded speaker drivers has vanished in little more than the blink of a technological eye.
Still, does any technology sound more high tech and futuristic as a fricking Ray Tube?
Buck would probably shed a tear for the passing of ray tubes into the boring of Light Emitting Diodes, so too would his contemporaries: Flash Gordon, Jack Swift, Brick Bradford, Don Dixon, Speed Spaulding, and John Carter.