Path: utzoo!utgpu!cunews!software.mitel.com!grayt From: grayt@Software.Mitel.COM (Tom Gray) Newsgroups: sci.electronics Subject: Re: Telephoe Equipment help! Message-ID: <7973@nst> Date: 16 May 91 18:38:45 GMT References: Organization: Mitel. Kanata (Ontario). Canada. Lines: 55 In article moonhawk@bluemoon.uucp (David Culberson) writes: : : Okay everyone, I have a question! Finally! For some time now, I :have had some telephone equipment, but that is all I know of them. They :all seem to be in perfect condition, but I have no idea what they are. I :have held off stripping the boards for parts, in case they should be : : 4-W RPTR : WITH DX : SSP-1240 : You have a four wire repeater with DX loop signalling. The unit will convert from E&M to DX type signalling. The 4W means that there are separate transmission circuits for each direction of the voice path. Essentially E&M is a very simple signalling scheme which is useful only for short distances. However it is very cheap and can be used to interconnect central office switches which are within the same building. DX (duplex) signalling can be used to carry signalling information (ie dialled digits, on hook, off hook) long distances. It is designed to function over telephone loops (interoffice trunks) with large resistances (ie 2K ohms), significant power line induction and standard office battery voltage. The device you have is designed to take a standard E&M trunk from a switch and convert it to the DX type trunk suitable for connecting to a distant CO. This equipment is placed in relay racks beside the switch. The reason for the vast number of dip switches is the vast number of variants of E&M and DX signalling that have been created in the last 100 years : They are made by a company called "TransCom", and the one I have :in my hand has a serial number of "VR4MGE4AA", at least I think it's a :serial number. it also says "LIST 2" on it. The 2 is on a sticker, tho. It :has two LED on the top of the face, the one on the left saying "E" over :top of it, and the one on the right saying "M". The date on this one says :"FEB 1 1987". There are banks and banks of dip switches inside, and a :daughterboard off of the main board hold the Bannana jacks and a few :resistors. There are a lot of switches on the board, hidden from the :front, and would be out of sight if it was in a chassis. Any help is :appreciated, and I would prefer EMAIL, but this conference is OK. : MoonHawk : :P.s. sorry 'bout the long message, I wanted to be clear! heh heh : : This is from : moonhawk@bluemoon.uucp : moonhawk%bluemoon@nstar.rn.com :who doesn't have their own obnoxious signature yet