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User:Darkroom/L System

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Transcontinental Cable System - L System

[edit]
SystemYearFrequencyCoax per cableDistance between repeatersCapacity
L-119413 mhz48 miles600 voice circuits
L-21942840 khz416 miles360 voice circuits
L-319538 mhz84 miles5,580 voice circuits
L-4196717 mhz202 miles32,400 voice circuits
L-5197257 mhz222 miles132,000 voice circuits

The Transcontinental Cable System was developed by AT&T to create a hardened telecom network for defense related communications during the cold war. There were five phases of development of the system, designated L-1 through L-5.

The system was designed to provide for land line connections between key command and control facilities inside the United States. Starting with L-4 the system was upgraded to withstand a nuclear attack. The system consisted of over 100 "Main Stations" and 1000 individual repeater vaults. The "Main Stations" had generators, blast doors and accommodations for staff for a two-week post-attack period.

In the late 1970's and early 1980's the system was determined to be redundant with the advance of satellite based communications. Most stations were never ugraded past L-4 due to advancement of technology.