Goodricke-Physics-Hub

This leg of the Current Broadcast Network carries the video and audio feeds from the studio through to the central distribution hub where it is distributed out to the various destinations on campus. It is now the oldest part of the network, having been in it's current form since the station moved to G/046 in 1994.

Structure

The cable route consists of a series of extensions added on at each major upheaval in YSTV's history to allow us to keep broadcasting via the existing infrastructure. It is therefore less than planned. From the studio a 150m unbalanced video cable (originally made for Breaker 88) and a 3-pair screened audio cable go through the window frame by the monitor rack, along the top of the G/045 windows and up over the room of the college nucleus. From here it wends it's way down along the covered walkway past the (old) Dining Hall and the bar to the "bus stop", then turns left past the cash machine towards the Physics and Electronics building. Just before the doors into this it goes through a hole in the wall of the building to reach the attic room above P/X/002.

old stuff to edit

The physics link, using entirely rediffusion cabling, was used from the 1970s onwards when YSTV moved from the original rediffusion studio / equipment room in PS016 on the physics spine corridor.

The link from LTC to PS016 is a standard rediffusion contribution setup, used the opposite direction to that originally intended. The single Physics->LTC contribution cable contains two pairs. One is used for broadcast (GoodrickeToPhysicsToLTC) and the other is used to return things to Physics/YSTV that would, originally, only have gotten as far as LTC. The same broadcast/return operation exists for the 6-pair audio contribution cable. Two pairs are used for the return (mono audio and comms) and one for broadcast (mono audio).

The 9-pair Rediffusion distribution cable is not touched by YSTV in PS016, it does however carry URY audio on the white twisted pair (Channel 'E'). See URYBroadcastNetwork. Routing

The run from LTC to PS016 is (unbroken) Rediffusion cabling, inside the covered walkway across the Central Hall bridge.

At PS016 the incomming balenced video signal on the twisted pair is received, amplified and unbalanced by an original Rediffusion No 6A amplifier, to drive a standard 75ohm coax output. The audio is just jointed (chocolate block!) without any active electronics.

Between PS016 and PX003, the video is on a 75R coaxial cable, and the audio on two twisted pairs, originally part of the contribution links from camera points in PX001 to the control room in PS016, now used in reverse. Note that this is Belden foil-braid cable not standard RG59, so fitting connectors is not easy.

This cable goes up through the cupboard in PS016 with all the incoming cables in it, into the ceiling void, and on down the spine corridor to the concourse. Somehow it gets into a 6" cable duct under the concourse floor, which splits to reach the covered way towards Central Hall, and emerge into PX003 somehow. How the latter gets there is uncertain, but may well involve the physics first floor calorifier room, accessed via a door from the PX003 attic. For more on the layout of these locations see the PhysicsDept page.

At PX003, the audio and video got straight through (passive) to the cables laid on top of the covered walkway between Physics and Goodrike. Return audio uses two of the three pairs in the grey cable (same cable type as used elsewhere in the 1998 broadcast network), and video is on 150m of standard RG59.

The return feed video cable is the one that comes down from above with the audio in PX003, not the one that comes up through the floor (which is net video). This has changed, so old documentation may list them the other way round. Both go to the control room anyway.

In the Goodricke control room both cables come in to the left of the monitor rack near the window. The audio cable goes to a piece of tag strip behing the rack, which splits it into three XLR connectors. The video comes out to trailing BNC, which should be marked, and coiled up on the window-ledge.

Until the direct Goodricke to LTC link is repaired (see GoodrickeToLTC) URY use the YSTV comms channel of this return as a bodged method of getting audio from Goodricke to URY. The wire is split in LTC to wherever YSTV want audio (usually Derwent) and to one channel of the Vanbrugh to LTC audio contribution, used in reverse (see VanbrughToLTC, VanbrughToURY?).