Update after 15 years maintenance!
Page being developed
First a view by the door showing how it should look. The battery box
has been rebuilt and now contains the batteries. The spares cabinet has
a new bridge shelf across to the table over the battery box. The spares
cabinet is now the correct item and the fuse cabinet mounted in a more
sensible place. A notice board finishes off the new look, and the small
SCOT terminal still has pride of place plugged into a proper D socket
mounted on the wall. Correct notices are also fixed up, and the steel
bar for mounting the heater has been replaced.
This shows the other front corner where a large PABX style rectifier
has been used in place of the correct type 103 which was missing, but
the correct switchboard has been mounted on top. On top of that is the
Ceptel solid state announcer unit, CP/M based using 5 1/4 inch floppy
disks. A standard GPO clock has been provided running from the local
pulse clock supply.
The MDF has been seriously tidied up
after many roughly finished jumpers had been left by Teradyne. I have
provided an EPG unit which would only be found in a main exchange under
normal circumstances, but hopefully I am allowed a few extra
Before we leave this end of the trailer
just another look back on the layout by the door. It is much more
conventional than the mess that Teradyne had left it in with bits of
the battery box etc having been carved up and used as shelves on the
wall, no front on the First aid box etc etc.
A general look down the centre isle of the equipment racks. Now fairly
tidy and well equiped with relay sets and selectors.
So now lets have a more detailed look at what we now have on the racks.
Here is a peek behind the suite with the RSR, AER and Group racks. The
blue boxes on the left are a bolt on extra from crossbar exchanges
which are useful here to decode DTMF dialling into Strowger pulses.
These are used for example, with incoming calls from the public
network. The main exchange alarm lantern is another of my "not really
correct" embelishments, but that having been said, one can never say
that anything was never done like that or is out of place, because
there are always exceptions! Note how narrow the working space is
behind the racks, compared to a normal autofloor exchange. Its not so
amusing after the first hour or two of wire wrapping (ask David)!
Here is a view looking back towards the
front. The call announcers and Divertacalls on the top left are an
addition which are used with incoming calls for automatic answering of
numbers to provide interest. The Announcers 12A were recovered from
Toll B in London and still contain some interesting announcements,
although the Eproms are starting to lose some data causing slight audio
corruption in places. But they are probably at least 40 years old!
And looking further down on the left we can see the test box has been
resupplied, another item which Teradyne removed.
This is the C&FC Linefinder shelf. Four unis had been stripped out
with their associated LF and K relays from the relay set above. They
are now replaced and all 10 linefinders work with the new C&FC 1st
selector shelf, see later below.
Another view of the C&FC linefinders
and the new test case. Also now provided is a test number on 5299, the
circuit for which is in one of the strip mount relay sets seen here.
The magnetically mounted test box is used for testing meter pulses,
full local call timing has now been implemented.
You will never see a row of test selectors like this in many exchanges!
Teradyne specialised in testing the routine test equipment they
developed for use by BT and other telcom providers. SCOT and 4TEL were
two examples of such equipment.
And finally, the shelf shown here of 1st selectors, mounted on the RSR
above the C&FC relays sets, was also a casualty of Teradyne's quest
for spares, they chopped and took the whole shelf out! Fortunately I
was able to locate an exact replacement for the shelf but this
did not overcome the enormous amount of work that had to be done to
reconnect the hundreds of wires on the bank outlet at the back. I have
just one payphone working in the K6 right now, but there are 4 more
circuits ready for me to use when there are enough days in the week to
do it all!
Last but not least I would like to thank the following for their help
and support over the last 15 years which made this recovery and
renovation possible. In particular without the work and support of
David I could not have coped with all the work involved on my own:
Teradyne who provided the MNDX
Ian Jolly who provided a suitable power unit swapping it over between
trailers in the dead of the night at a Little Chef car park somewhere
Nick Wellington who provided spare parts from recycled trailers
Steve Cashmoor who helped find spare parts at the bitter end of the
David Williams who helped with everything else!
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This page is maintained by Martin