https://www.rainsbrook.co.uk/wiki/ 2026-05-01T04:20:50+00:00 https://www.rainsbrook.co.uk/wiki/ https://www.rainsbrook.co.uk/wiki/lib/exe/fetch.php?media=wiki:dokuwiki.svg text/html 2025-11-06T11:35:22+00:00 Anonymous (anonymous@undisclosed.example.com) https://www.rainsbrook.co.uk/wiki/doku.php?id=telecoms:alphafubapsu&rev=1762428922&do=diff Alpha and Fuba PSU A ferroresonant transformer (also known as a Constant Voltage Transformer or CVT) made by the manufacturer FUBA was used in older CATV (Cable Television) systems as a robust and reliable power supply component. Its primary function was to provide a stable, regulated AC output voltage to power active components like line amplifiers in the cable network, even when the input AC mains voltage fluctuated significantly. Key characteristics and purpose in CATV systems: text/html 2025-01-31T11:02:05+00:00 Anonymous (anonymous@undisclosed.example.com) https://www.rainsbrook.co.uk/wiki/doku.php?id=telecoms:ascom-bt-kilostreamnte&rev=1738321325&do=diff Ascom | BT kilostream NTE This is I believe the manufacturers version of the BT branded BT shelf 4a. This page has been accessed for:- Today: 0 Yesterday: 0 Until now: 0 text/html 2025-02-06T00:19:38+00:00 Anonymous (anonymous@undisclosed.example.com) https://www.rainsbrook.co.uk/wiki/doku.php?id=telecoms:bt-adsl&rev=1738801178&do=diff BT ADSL cab This page has been accessed for:- Today: 0 Yesterday: 0 Until now: 0 text/html 2022-11-10T00:17:00+00:00 Anonymous (anonymous@undisclosed.example.com) https://www.rainsbrook.co.uk/wiki/doku.php?id=telecoms:bt-eqpt-term-24a-25a&rev=1668039420&do=diff BT Eqmt Terminating No. 24A / 25A This unit comprises two halves each which houses an Alarm Unit 85A and a Line Terminating Unit 11A / 1 / 2. It's inputs are twisted pairs but the outputs are on two BNC connectors. I suspect that it is a 2MB/s device, but this is a calculated guess based on BNC and the internal coax connectors being used for 2MB/s circuits elsewhere ( but also for 34MB/s ), and the twisted pair line side connections could carry 2MB/s with SDSL, but the circuitry on the LTU card… text/html 2025-09-26T10:05:41+00:00 Anonymous (anonymous@undisclosed.example.com) https://www.rainsbrook.co.uk/wiki/doku.php?id=telecoms:bt-fibre&rev=1758881141&do=diff BT Fibre internet [Clearly everyone has their own submarine fibre cable to their house.... :-} ] More accurately, OpenReach Fibre internet. This is wrong I realise now, the OpenReach Fibre provision uses Time division Multiplex as well as Wavelength Division Multiplex to pass the up and downstream signals. The TDM part is used to pass data to multiple subscribers on their own timeslot, but WDM is used to separate the up and downstream traffic. This is part of the Gigabit Passive Optical Netw… text/html 2021-01-06T22:11:59+00:00 Anonymous (anonymous@undisclosed.example.com) https://www.rainsbrook.co.uk/wiki/doku.php?id=telecoms:bt-ltu16&rev=1609971119&do=diff BT LTU16a Unusual LTU as this is in a metal case. No real indication what it does except for the marking on the top@- “ 'A' Line Services”. This seems to be a passive unit with transformers and capacitors presumably for line equalisation. Certainly a simple unit. text/html 2022-11-10T00:18:30+00:00 Anonymous (anonymous@undisclosed.example.com) https://www.rainsbrook.co.uk/wiki/doku.php?id=telecoms:bt-ltu23&rev=1668039510&do=diff LTU chassis This is a common chassis which provides the usual -50v / 0v telecom power and can house different LTU. BT LTU23c I have two variants of these, both rack mounted in a 3U chassis, both are made by Telspec. I believe in normal use, there would be a two pronged jumper to link vertically, and for testing these could be removed and inserted horizontally to loop back.000 text/html 2025-12-01T00:33:28+00:00 Anonymous (anonymous@undisclosed.example.com) https://www.rainsbrook.co.uk/wiki/doku.php?id=telecoms:bt-ltu25&rev=1764549208&do=diff STC-LTU25D STC-LTU25D is a 64kb/s kilostream Line Terminating Unit. Three LJU style connectors are provided, the left hand side is the Kilostream circuit, the two right hand side ones are for dial on demand backups using analogue phone lines. These would appear to be normal PSTN Master Sockets. text/html 2021-01-07T10:57:50+00:00 Anonymous (anonymous@undisclosed.example.com) https://www.rainsbrook.co.uk/wiki/doku.php?id=telecoms:bt-ltu30&rev=1610017070&do=diff BT LTU30d text/html 2021-01-07T10:58:25+00:00 Anonymous (anonymous@undisclosed.example.com) https://www.rainsbrook.co.uk/wiki/doku.php?id=telecoms:bt-ltu35&rev=1610017105&do=diff Fujitsu-LTU35A Fujitsu LTU35A is a 64kb/s kilostream Line Terminating Unit. [ ] Three LJU style connectors are provided, the left hand side is the private circuit, the two right hand side ones are for dial on demand backups using analogue phone lines. text/html 2021-01-07T13:00:53+00:00 Anonymous (anonymous@undisclosed.example.com) https://www.rainsbrook.co.uk/wiki/doku.php?id=telecoms:bt-ltu37&rev=1610024453&do=diff BT LTU37a This LTU is again made by Telspec and seems similar to the other LTU units, it has one LJU for the data circuit and two LJU sockets for an analogue phone connection. text/html 2021-01-07T13:01:17+00:00 Anonymous (anonymous@undisclosed.example.com) https://www.rainsbrook.co.uk/wiki/doku.php?id=telecoms:bt-ltu45&rev=1610024477&do=diff BT LTU45a LTU chassis This is a common chassis which provides the usual -50v / 0v telecom power anc can house different LTU. LTU This seem to be similar to the LTU23C/A. As both are in the same chassis, presumably they serve different functions and are not just a newer version. text/html 2026-02-05T14:50:58+00:00 Anonymous (anonymous@undisclosed.example.com) https://www.rainsbrook.co.uk/wiki/doku.php?id=telecoms:bt-nte1h-7a&rev=1770303058&do=diff BT NTE 1H/7A Fujitsu NTE 1H/7A is part of the Access SDH range. It is an sdsl modem which terminates a leased line, presented as either a G703 or X21 interface. It is usually line powered but looks like it can also be locally powered. This unit was used to provide an internet circuit over a 2MB's line, it connected to a rather ancient text/html 2025-06-13T22:18:12+00:00 Anonymous (anonymous@undisclosed.example.com) https://www.rainsbrook.co.uk/wiki/doku.php?id=telecoms:bt-nte8a&rev=1749853092&do=diff BT nte8a 2MB/s X21 on a 15pin D connector to G703 converter on two BNC sockets. [Front] [Back] ---------- This page has been accessed:- Today: 0 Yesterday: 0 Until now: 0 text/html 2022-11-10T00:19:26+00:00 Anonymous (anonymous@undisclosed.example.com) https://www.rainsbrook.co.uk/wiki/doku.php?id=telecoms:bt-nte16u&rev=1668039566&do=diff BT NTE16U/7A This NTE declares itself part of the Access SDH range, it comprises 16 2mb/s tribs multiplexed to a 34MB/s “F” type fibre connection, presumable single mode fibre. It seems to be made by Fujitsu from the markings on the PCB. The tribs have connections for G703 on coax (BNC), G703 on 120Ohm twisted pair (RJ45) and V21 on a 15p 000 text/html 2025-09-01T15:32:45+00:00 Anonymous (anonymous@undisclosed.example.com) https://www.rainsbrook.co.uk/wiki/doku.php?id=telecoms:bt-nte51-2&rev=1756740765&do=diff BT NTE51 & NTE52 Another x21 / G703 NTE, these have incoming circuits presented over sdsl on two pairs of copper. These are both used to present primary rate ISDN circuits to a Cisco WIC card. Both these units are line powered. NTE51 According to the LEDs, this can present 1MB/s or a 2MB/s connection. text/html 2021-01-07T17:41:15+00:00 Anonymous (anonymous@undisclosed.example.com) https://www.rainsbrook.co.uk/wiki/doku.php?id=telecoms:bt-ntu6a&rev=1610041275&do=diff BT NTU6A/2 This is a 4w wire Network Termination Unit, it seems to have an x21 output. As this is a kilostream unit, it will have a max data speed of 64kb/s. text/html 2021-01-07T17:41:47+00:00 Anonymous (anonymous@undisclosed.example.com) https://www.rainsbrook.co.uk/wiki/doku.php?id=telecoms:bt-ntu7a&rev=1610041307&do=diff BT NTU7A/2 4-wire to X21 Kilostream NTE, used for a varety of speeds, 64k, 128k, 192k or 256k according to the front panel LEDs. The incoming line side is plugged in on a standard LJU plug. This looks like it would have had a local power supply. text/html 2025-01-31T11:05:10+00:00 Anonymous (anonymous@undisclosed.example.com) https://www.rainsbrook.co.uk/wiki/doku.php?id=telecoms:bt-shelf4a&rev=1738321510&do=diff BT shelf 4a BT version This is a 6U rack mount enclosure for up to 12 NTU. It seems to be very similar to one made by Ascom although the NTU6B searches on the internet all return Marconi links. There is a common PSU module with a single mains power inlet, and a common display and control module for all the plug in cards. The rear panel on mine has a row of IDC header plugs for external connections.000 text/html 2021-01-07T17:43:24+00:00 Anonymous (anonymous@undisclosed.example.com) https://www.rainsbrook.co.uk/wiki/doku.php?id=telecoms:bt-sigunit61&rev=1610041404&do=diff BT Signalling Unit 61B Manufactured by KelTel, from their website:- “A product marketed for many years by both Keltek & BT (61B). Converts between DC5 2W and a simple telephone. Keltel can supply the original ROLI MkII previously sold by Keltek Electronics and BT as the 61B. The unit is housed in a small standalone enclosure with its own internal mains power unit. Converts from a standard 2W telephone or system trunk port to 2W E&M for connection to a router, mux or radio set. Keltel also suppl… text/html 2021-01-07T17:43:51+00:00 Anonymous (anonymous@undisclosed.example.com) https://www.rainsbrook.co.uk/wiki/doku.php?id=telecoms:bt-sigunit101&rev=1610041431&do=diff BT Signalling Unit 101A From the BT User Instructions.... The unit provides the following ports:- * Line Interface port (2w or 4w) * Customer Interface port (2w or 4w, E+M and sig earth out and Signal rail in) * Power supply port, my rack was locally powered by the usual -50v and 0v power. text/html 2021-01-07T17:44:57+00:00 Anonymous (anonymous@undisclosed.example.com) https://www.rainsbrook.co.uk/wiki/doku.php?id=telecoms:bt-transformerunit9a&rev=1610041497&do=diff BT Transformer Unit 9A/A Not at all sure what these are, but from the age and location I think it is POTS rather than data related. Possibly loading coils for long cable runs? text/html 2022-05-03T10:00:46+00:00 Anonymous (anonymous@undisclosed.example.com) https://www.rainsbrook.co.uk/wiki/doku.php?id=telecoms:cabletelecoms&rev=1651572046&do=diff Telecoms - Cable TV Coventry Cable TV * Coventry Cable TV * Coventry Cable - Local Programming Kabel TV Eindhoven Virgin Media HFC Virgin Media Fibre City Fibre BT ADSL cab This page has been accessed for:- Today: 0 Yesterday: 0 Until now: 0 text/html 2022-11-10T00:13:45+00:00 Anonymous (anonymous@undisclosed.example.com) https://www.rainsbrook.co.uk/wiki/doku.php?id=telecoms:cityfibre&rev=1668039225&do=diff City Fibre ( Vodafone ) Intro The latest addition to digging up Coventry:- [City Fibre logo] These pics were taken during the dig in the north part of Coventry. There is a lot of similarity it seems, to the way Virgin Media Fibre are providing “Real” fibre connections, but there are big differences too. It is a mix of underground and overhead connections, it seems that if the ducts are passing a property, the connections are underground, but for those properties not passed directly, a fibr… text/html 2026-03-17T21:08:52+00:00 Anonymous (anonymous@undisclosed.example.com) https://www.rainsbrook.co.uk/wiki/doku.php?id=telecoms:covcable-localprogramming&rev=1773781732&do=diff Coventry Cable - Local Programming Coventry Cable started with lofty ideas of providing a local channel, funded partly through advertising. In the Whitley Village building, there was a studio and edit suites built to facilitate this. Unfortunately, due to the lower numbers of subscribers and the small advertising revenue the local programming was scaled back to a volunteer based operation and eventually ceased altogether.000 text/html 2025-11-06T12:23:53+00:00 Anonymous (anonymous@undisclosed.example.com) https://www.rainsbrook.co.uk/wiki/doku.php?id=telecoms:coventrycable&rev=1762431833&do=diff Coventry Cable TV Now defunct, the original build was for 450MHz bandwidth carrying about 30 TV channels as well as the FM radio spectrum. It was built and operated by BT and along with the likes of Milton Keynes was one of the first franchises in the UK.000 text/html 2025-06-11T10:05:59+00:00 Anonymous (anonymous@undisclosed.example.com) https://www.rainsbrook.co.uk/wiki/doku.php?id=telecoms:dmc-4x2mb&rev=1749636359&do=diff Digital Microwave 4x2Mb/s to 8MB/s multiplexer These are some more pics of DMC PDH kit from Baskerville House. These seem to be 2MB/s tribs to an 8MB/s uplink. ---------- This page has been accessed:- Today: 0 Yesterday: 0 Until now: 0 text/html 2025-06-11T10:05:21+00:00 Anonymous (anonymous@undisclosed.example.com) https://www.rainsbrook.co.uk/wiki/doku.php?id=telecoms:dmc-16x2mb&rev=1749636321&do=diff Digital Microwave 16x2Mb/s to 34MB/s multiplexer These are some pics of some old DMC PDH kit recovered from a building stripout (Baskerville House in Birmingham). The kit is made by DMC (Digital Microwave Corporation). It seems to consist of four 2MB/s tribs multiplexed to 8MB/s and then four of the 8Mb/s multiplexed to create the 34MB/s signal which leaves the device on single mode fibre.000 text/html 2022-11-10T00:12:24+00:00 Anonymous (anonymous@undisclosed.example.com) https://www.rainsbrook.co.uk/wiki/doku.php?id=telecoms:kabeltveindhoven&rev=1668039144&do=diff Kabel TV Eindhoven Background In the Mid 1990s, I had the opportunity to visit Eindhoven in the Netherlands and I managed to blag a visit to the local cable TV operator. Head End Unlike in Coventry at a similar time, the head end was located in a flat rented at the top of a tower block of just ordinary accommodation. The antenna for Satellite and Terrestrial were on the roof of the tower block. Due to the height, a high gain antenna was able to pick up UHF TV for BBC and ITV broadcast from … text/html 2025-02-08T00:29:48+00:00 Anonymous (anonymous@undisclosed.example.com) https://www.rainsbrook.co.uk/wiki/doku.php?id=telecoms:ntu8a&rev=1738974588&do=diff ntu8a text/html 2021-01-07T17:55:57+00:00 Anonymous (anonymous@undisclosed.example.com) https://www.rainsbrook.co.uk/wiki/doku.php?id=telecoms:oms840&rev=1610042157&do=diff Marconi OMS840 Add Drop Multiplexer This was fitted to an office I worked in, basically it had two fibre ports (I believe 155MB/s) to connect back to a dual ring SDH network (The picture shows only one sfp and fibre fitted) and split out two 100MB/s ethernet ports for data usage and four 2MB/s circuits for telecoms usage. text/html 2025-09-01T23:14:35+00:00 Anonymous (anonymous@undisclosed.example.com) https://www.rainsbrook.co.uk/wiki/doku.php?id=telecoms:pdh-sdh&rev=1756768475&do=diff Nokia PDH and Marconi SDH The original Mediahub project 2MB/s leased lines were presented from a Nokia 34MB/s PDH “box” on the wall. When we moved site, Telewest provisioned these with a rack mount version, and on the day of the move, cut over in their network the optical fibre to each. In due course, we added more sites and Telewest needed to add more leased lines to service them. This time we were provided with an SDH rack mount Add Drop Multiplexer. 000 text/html 2025-07-02T22:28:51+00:00 Anonymous (anonymous@undisclosed.example.com) https://www.rainsbrook.co.uk/wiki/doku.php?id=telecoms:procatv-status-dwgs&rev=1751495331&do=diff ProCATV Status Monitor Circuit Diagrams FSK Transmitter (Frequency Shift Keying) Analogue Status Monitor Digital Status Monitor This page has been accessed:- Today: 0 Yesterday: 0 Until now: 0 text/html 2025-10-13T14:28:34+00:00 Anonymous (anonymous@undisclosed.example.com) https://www.rainsbrook.co.uk/wiki/doku.php?id=telecoms:scii-isdn&rev=1760365714&do=diff SCII Telecom ISDN PCI card Somewhat unknown PCI card for basic rate ISDN (I think from the chipset on board), this card would appear to provide two basic rate ISDN inputs on RJ45 and one analogue phone output on RJ11. Chipset on board is two Siemens PSB2115H for ISDN and one Siemens PSB2161T for the analogue phone. text/html 2025-06-13T22:19:44+00:00 Anonymous (anonymous@undisclosed.example.com) https://www.rainsbrook.co.uk/wiki/doku.php?id=telecoms:start&rev=1749853184&do=diff Telecoms Index 3 3Com Cellplex 7000 3Com - 3c108 AUI transceiver (Medium Attachment Unit, MAU) 3c588 - 3Com Multiconnect repeater hub A Ascom | BT kilostream NTE B BT Eqmt Terminating No. 24A / 25A BT LTU16a BT LTU chassis BT STC-LTU25D BT LTU30d BT Fujitsu-LTU35A BT LTU37a BT LTU45a BT NTE 1H/7A BT nte8a BT NTE16U/7A BT shelf 4a BT Signalling Unit 61B BT Signalling Unit 101A BT NTU6A/2 BT Transformer Unit 9A/A BT ADSL cab BT Fibre internet C Telecoms - Cable TV C… text/html 2021-01-12T16:28:30+00:00 Anonymous (anonymous@undisclosed.example.com) https://www.rainsbrook.co.uk/wiki/doku.php?id=telecoms:structured&rev=1610468910&do=diff Structured Cabling Structured cabling refers to a planned and organised way to wire data cabling in a building, usually this will be Cat5e cable terminated on an RJ45 patch panel at the wiring centre end and RJ45 faceplates at the user's end. This is a flexible way to carry data and telephone traffic, but I have not seen much info about how to wire the incoming telephone circuit to the patch panel. This attempts to rectify the position. Thanks to Robert Bradley (who will know who he is if he ev… text/html 2021-01-12T13:22:04+00:00 Anonymous (anonymous@undisclosed.example.com) https://www.rainsbrook.co.uk/wiki/doku.php?id=telecoms:testsocket&rev=1610457724&do=diff Test Socket Shown is a kilostream faceplate with one socket for normal use and the other for testing. Swapping the CPE and the test plug over loops the incoming line with the test plug and the cpe with the socket (as shown in the rear view). text/html 2025-11-06T16:53:15+00:00 Anonymous (anonymous@undisclosed.example.com) https://www.rainsbrook.co.uk/wiki/doku.php?id=telecoms:texscanamp&rev=1762447995&do=diff Texscan wideband amplifier Overview External casing:- ---------- Forward Path [Fully Loaded amp] Fully loaded amplifier with power mod, splitter and status monitor kit. Diplex filters are splitters, the Pad and Equal modules are just a flat 3dB attenuator for example, the Equal is a a frequency equalisation module (Americanism is 000 text/html 2021-01-07T13:04:50+00:00 Anonymous (anonymous@undisclosed.example.com) https://www.rainsbrook.co.uk/wiki/doku.php?id=telecoms:unknownltu&rev=1610024690&do=diff Unknown LTU text/html 2023-08-09T11:23:29+00:00 Anonymous (anonymous@undisclosed.example.com) https://www.rainsbrook.co.uk/wiki/doku.php?id=telecoms:virginmedia&rev=1691580209&do=diff Virgin Media Network Cabinet left with unlocked door.... The Coax part of the HFC (Hybrid Fibre Coax) network. Despite the size of the cabinet, there is no evidence of any DOCISS equipment for internet access. This is a pre-fibre rollout area, the left hand shows a Teleste AC2000 wideband RF amplifier, (see 000 text/html 2024-03-27T14:41:20+00:00 Anonymous (anonymous@undisclosed.example.com) https://www.rainsbrook.co.uk/wiki/doku.php?id=telecoms:virginmediafibre&rev=1711550480&do=diff Virgin Media Fibre Background The old and the new, the larger cabinet is part of the rather ancient Coventry Cable TV network which ceased ages ago. The smaller cabinet is the part of the new fibre roll out and collects all the consumer blown fibre conduits. Streetworks 000 text/html 2022-05-26T11:14:09+00:00 Anonymous (anonymous@undisclosed.example.com) https://www.rainsbrook.co.uk/wiki/doku.php?id=telecoms:x21loopback&rev=1653563649&do=diff X21 Loopback Plug From a note I found. May not be correct. 15 Pin D connector Pin Function 2 - 4 3 - 5 6 - 13 9 - 11 10 - 12