moonhawk@bluemoon.uucp (David Culberson) (05/14/91)
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
useful, valuable, or both. They are like expantion cards, but each has a
face to it. They have 8 bannana plugs on the front, seperated into two
banks called the "A" side and the "b" side. There is a pot on them labeled
"Gain (A->B)". They have model numbers on the front saying:
4-W RPTR
WITH DX
SSP-1240
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 yetgrayt@Software.Mitel.COM (Tom Gray) (05/17/91)
In article <q4Tw23w164w@bluemoon.uucp> 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 yetjohn@zygot.ati.com (John Higdon) (05/19/91)
In article <7973@nst> grayt@Software.Mitel.COM (Tom Gray) writes: >In article <q4Tw23w164w@bluemoon.uucp> moonhawk@bluemoon.uucp (David Culberson) writes: > >: 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. Practically speaking, this unit is used by telcos to provide DX>E&M conversion for end users. A typical use would be for a customer to connect two PBX switches in separate locations (maybe even separate cities) together. He orders an "E&M tie line" from telco. This line has a separate pair for each direction of speech plus an "E" and an "M" lead that the PBXes use to signal to each other -- the "E" lead becoming the "M" lead at the other end and visaversa. This signaling can be off-hook, supervision, and even dialing. It is not practical to send these signaling leads over long distances, so the telco "phantoms" the information between the two voice pairs ("DX signaling") between the customer location and the CO. For an explanation of "phantom", see a telecom reference book. E&M signaling is not used much within telcos anymore, but rather by customers. -- John Higdon | P. O. Box 7648 | +1 408 723 1395 john@zygot.ati.com | San Jose, CA 95150 | M o o !