I found this link, wondered if any of it was true? I guess if they killed analog radio to all HD I'll need to go to XM to be able to get anything.
http://tech.yahoo.com/blogs/null/145092
http://tech.yahoo.com/blogs/null/145092
Tom Wells said:Can someone tell me why phone dialing went from digital to analog? I mean, it was pure digital for 75 years before they
"upgraded" dialing to dual-tone analog sinewave decoding. Just wondering.
stormy01 said:I believe in part, the old dial phone technology generated pulses that the 'switch' needed to drive the relays. Digital was deemed more efficient since relays consumed a lot more power than digital, took up a lot of floor space and they were mechanical, which were subject to breakdown.
landtuna said:stormy01 said:I believe in part, the old dial phone technology generated pulses that the 'switch' needed to drive the relays. Digital was deemed more efficient since relays consumed a lot more power than digital, took up a lot of floor space and they were mechanical, which were subject to breakdown.
Correctomundo! Those old mechanical relays were about the size of a large coffee can. With the explosion of phone numbers over the past 30 or so years it would have been a nightmare to build central offices large enough to hold all the equipment necessary. Also, the relays cannot be programmed. They merely connect or disconnect. With touch-tone dialing a computer can interpret the different commands (which is what the tones actually are) and perform functions other than connect/disconnect.
Those old central offices were way louder than an automobile factory with all the switching going on.
stormy01 said:Keeping track of all those relays would have been a great career upgrade from being a bean counter!
(and don't forget the ear protectors)
landtuna said:Got out of the central office and into PBX and Long Lines as fast as possible!
oldiesfan6479 said:"Long Lines" as in the old TV network lines or POTS long distance?
Nick said:Here's an example of something that went digital that is much superior to its analog replacement: CDs and DVDs.
Records and tapes have noise and can be easily destroyed, and tapes have a short life. A CD or DVD burned today will outlive your children.
Savage said:NO, "analog radio will NOT go dark in 2015."
Lee Rust said:Digital radio works in the real world only if there are multiple line-of-sight signal paths dynamically available to the transmitter/receiver system, as with cellular phones. Even so, dropped calls are common.