Selection and Testing of Electronic Components for LM

ABJ 101-the Modern Public
Magneto Switchboard
Lennart Aldestam
The demand for manual magneto switchboards has increased considerably during
recent years. There are large areas where conditions are such that magneto switchboards
offer a satisfactory and economical solution to the telecommunication
problems as also long lines of not very high quality can be connected.
In order to meet this growing demand LM Ericsson, in close cooperation with
many of their customers, have developed a modern, single-position magneto
switchboard designated ABJ 101. ABJ 101 can operate either as an independent
exchange or in combination with an automatic exchange (PAX), AKD 860.
UDC 621.395 343
Fig. 1
ABJ 101 equipped for 40 magneto lines, 4 CB
junction lines and 10 cord pairs
1. Base unit
2. Line shelf
3. Line unit for magneto lines
4. Line unit for CB junction lines
5. Supervision unit
6. Cord pair unit
7. Position unit
ABJ 101 -a compact and
flexible switchboard
ABJ 101 is a compact and modern
magneto switchboard with all equipment
built into the chassis. The
switchboard has a modular structure,
fig. 1, and the units are connected via
plugs and jacks, which means simple
and fast installation.
This construction gives a low initial cost
and permits extension in stages. No
special tools are required for assembling
and installing the switchboard.
Owing to the fact that the switchboard is
built up of such components as miniature
relays and cord winders it has very
small dimensions and thus requires
only a third of the volume of space required
for traditional floor switchboard.
ABJ 101 can be placed on a desk, counter
etc. and merges well with different
surroundings. The small dimensions
mean that it is usually very easy to find
a suitable place for the switchboard.
Can be extended from 10 to 240 lines
The switchboard can be extended in units
of ten magneto lines, four CB junction
lines and one cord pair.
The final capacity is 18 cord pairs and
either 240 magneto lines or 220
magneto lines and 8 CB junction lines,
fig. 2. Thus the system covers a very
wide capacity range. The switchboard is
already wired for full capacity when delivered.
All apparatus is inserted from
the front.
Administrations with several switchboards
may find it advantageous to
stock extension equipment themselves.
The cost of this will be small.
High operator efficiency
A summary of the most important
characteristics of ABJ 101 is given at the
end of the article. Many of these
characteristics are such that they enable
the operator to handle a larger
amount of traffic and provide better
service for the subscribers.