Odds and ends 1 

Trunk offer (TKO)

This circuit never had a proper name so for want of calling it something it was known as a TKO selector.

One day while standing watching the trains the phone rang on platform 2 at Ropley, the only member of staff, who happened to be on platform 1 went off to answer it, needless to say before he reached the phone the caller cleared down.

The TKO selector worked in the following manner, to answer a ringing phone one could use another phone dial 6 followed by the number of the ringing phone and answer the call remotely. Safeguards were built in to prevent someone accessing an established call.

Based on a Information Services final selector used for 80XX calls (TIM etc) in a main exchange.

Installed in all four exchanges it can be seen in the picture below on the top shelf at Alresford -shelf position 10 

Recorded information services

Sometimes a message needed to be given a large number of people, instead of circulating pieces of paper a number was introduced at Alresford - 2211. This was connected to relay sets which gave access to a recorded message. The message could be easily changed.

The sets are shown above located in a relay set shelf in positions 1 and 2.

Info circuit

Another circuit with no name, most calls were answered by the Information Office on a KLU, if they wanted to transfer the call to another KLU they used the internal system to advise a call was for transfer. Each time this meant dialling a 4 digit number.

A circuit was devised connected to a spare Info Office KLU key, operating the key connected to a relay set which seized a free final selector, dial tone was returned and only the last 2 digits needed to be dialled cutting down on time and wear on the equipment.

Call transfer

Incoming exchange lines were connected to PABX4 exchange line relay sets, calls could be transferred to extensions via an enquiry circuit and dedicated final selectors, seen above - the 4 smaller selectors on the top shelf.

It was also possible to transfer a call to Ropley.

The introduction of the KLUs removed the main need for these circuits except for non KLU connected extensions, this was only fully solved with the introduction of the Panasonic and later switches.

Clocks

A mechanical master clock was installed at Alresford and eventually fed clock pulses up the line to Alton, it was later replaced with an Electronic Pulse Generator 2A.
One major problem was the cable pairs feeding the 30 second clock pulses to the other stations; this was the time when there was major rodent damage to the cables. Steps attempted to over come the problems were a local EPG being installed at each station, this would run the local clocks if the incoming clock pulse was missing or there was a permanent pulse. Eventually the clocks were removed at all stations except Alresford, nobody complained so there are no plans to restore them.

Power units

With the introduction of digital units in small country exchanges we obtained a number of surplus Power Plant 2040s, these have two 28 amp switched mode rectifiers, only one being in service and two 50 volt batteries,
Each exchange has one of these units, they also run the Norstar switches via a mains inverter. There is also a 50 volt feed to the signal boxes for miscellaneous telephone items located there.

Carrier

Some 24 channel Plessey carrier equipment was donated to the railway, the transmission quality of the original cables was poor and it was hoped this would improve matters.

Four racks were obtained and 3 were installed, Alresford, Medstead and Alton, there being no space at Ropley for a rack.

It took some time arranging collection and by the time the equipment was obtained the cables were in terminal decline, although 2 racks were connected and some tests were undertaken between Medstead and Alton the carrier equipment was never used in service.

New cable with a larger sized conductor improved the transmission quality of the analogue circuits, later digital trunks removed the need for the carrier equipment and it was scrapped.  

Other carrier equipment obtained prior to the 24 channel system was ex BR valve type and some 4 channel transistor equipment. Neither was ever used.

Two 62 type carrier racks

1 plus 4 carrier shelves

CFDE

Call failure detection equipment - this was salvaged from a public exchange and adapted to work on the railway Strowger system.

The first was fitted at Alresford, when a call was originated the CFDE would connect to the first selector and monitor the digits dialled, within a set time a tone would be expected, if no tone was detected after this period a failure meter would step and the number dialled printed out.

Meters recorded the number of calls to each exchange and the number of successful calls that were answered, it was found a lot of calls were abandoned before dialling was completed. In the picture at the top of the page this equipment comprised of relay sets in positions 5 to 9 of the relay set shelf. A second unit was later fitted at Alton.

Meters from the Alresford unit, found in March 2009 during a stores tidy up.  

Mobile exchanges

The railway has 2 Strowger caravans, 5 MXE vans containing TXE2 equipment and one used for telegraph equipment on site, all came equipped but are now used for storage.

Happy memories of maintaining a 2000 line MXE unit in Winchester in the late 1970s early 1980s, lots of call outs due to faulty reed relay inserts. 

TXE2 van seen at Yateley exchange prior to transport to the railway

Telegraph van at Alresford, it is still on its wheels.

When this van arrived BT got into a bit of a panic as there was something inside which shouldn't have been sent, once retrieved the keys were handed over, the official story was someone had left their tools inside! Whatever its intended use it was apparent it had never been used for such, there was a un-jumpered MDF, the blocks had never been soldered, un-equipped 62 type racks and a Teleprinter 15, with a note stating due to security perforator tapes should be destroyed.

MNDX 105 at Ropley November 2008 

Teleprinters

Someone thought it would be a good idea to have a teleprinter at each station, this being before the FAX machine became common.

Some teleprinter 15s were obtained, however they did not have dialling facilities so some means were needed to switch the associated circuits. The printer circuits all terminated at Ropley and to send a message the originator would dial 49XY from a phone, 49 routed to the connecting circuit, X would indicate to the equipment the originating printer and Y the terminating one, the 2 printer circuits were then connected. The caller would hear tones via the phone, one being an indication if the distant printer was switched off.

Replacing the handset would terminate the call.

Despite initial enthusiasm the system rapidly fell into decline and the service withdrawn, recently the connecting circuit was found in a loft, pictured below, minus some bits.

Odds and ends 2

Odds and ends 3

Odds and ends 4

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