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rb:coventrycable [27/05/2018 22:30]
andrew [Consumer Distribution]
rb:coventrycable [26/06/2018 00:37] (current)
andrew [Supertrunk]
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 ===== Supertrunk ===== ===== Supertrunk =====
  
-The Supertrunks radiated out from the Head End to distribution sites prior to feeding the local distribution network. These consisted of several amplifiers with one input and one output boosting the signal. The amplifiers were nothing special, just the same as the DLA (Distribution Launch Amplifier) amplifiers but run at lower gain (ie. less noise added to the signal), the supertrunk coax was about 2 inches ​in diameter for minimum signal loss. Due to the inflexibility of the low loss cable, the link to the cabinet was on reduced size cable with the joint in a chamber adjacent to the cabinet (left hand side next to road below)+The Supertrunks radiated out from the Head End to distribution sites prior to feeding the local distribution network. These consisted of several amplifiers with one input and one output boosting the signal. The amplifiers were nothing special, just the same as the DLA (Distribution Launch Amplifier) amplifiers but run at lower gain (ie. less noise added to the signal), the supertrunk coax was about 40mm in diameter for minimum signal loss. Due to the inflexibility of the low loss cable, the link to the cabinet was on reduced size cable with the joint in a chamber adjacent to the cabinet (left hand side next to road below)
 The supertrunk amplifiers were located in smaller green BT fibreglass cabinets and were all line powered from either end of the trunk. The supertrunk amplifiers were located in smaller green BT fibreglass cabinets and were all line powered from either end of the trunk.
  
 {{rb:​20180519_115423.jpg?​400|}} ​ {{rb:​20180519_115350.jpg?​150|}} {{rb:​20180519_115423.jpg?​400|}} ​ {{rb:​20180519_115350.jpg?​150|}}
  
-This seems abandoned, the door to this has been lying on the grass for several months.+This cabinet ​seems abandoned, the door to this has been lying on the grass for several months
 + 
 +{{:​rb:​core1.jpg?​200|}} {{:​rb:​core2.jpg?​200|}} {{:​rb:​labelling-disc-spacing.jpg?​500|}}\\ 
 +This is the supertrunk cable, it is an aluminium core with a copper cladding (The aluminium will carry most of the AC line power, whilst the copper will carry the RF due to the "Skin Effect"​),​ the dielectric is polyethylene with air spacing to reduce loss but periodic "​Discs"​ of polyethylene to provide support for the core, the screen comprises a copper foil wrapped with an aluminised plastic enclosed in a black plastic sheath. 
 + 
 +The right side picture shows the cable manufacturer and codes, as well as showing the position of the dielectric discs supporting the core.
 ===== Distribution ===== ===== Distribution =====
  

rb/coventrycable.txt · Last modified: 26/06/2018 00:37 by andrew