Ropley comms room - thanks to the services of Acme Carpets we now have some carpet on the floor.
Delay unit AT612230
This unit is included as it featured in so many Mid Hants circuits, originally used in sleeve control switchboards to start the clock timing a call, it gave a delay of 320 milli-seconds after a start condition was applied and the type 23 relay operating.
There are 2 circuits in the unit and takes the space of two 3000 type relays.
It was found by increasing the size of the capacitor delays of up to 90 seconds could easily be obtained, these were used in an S and Z pulse generator. Another version with a delay of around 4 seconds would force release a call if a spare number was dialled and the caller given number un-obtainable tone.
Another variation was used to detect how many keys were operated on the SPT concentrators, to prevent the signal person attempting to speak to 2 or more SPTs at the same time the delay unit detects how many keys are operated, more than 1 and the transmission path to all SPTs is disconnected.
Electronic dial tone
All four Strowger exchanges had electronic dial tone generators mainly for the reason a number of units had been obtained, also some MF to LD converters were installed and the frequency of the dial tone had to be changed.
With some alterations these units form the electronic ring tone generator for the SPT equipment.
Another use for a telephone box
Info line
Situated at Alresord is an Information Office, this deals with most of the incoming telephone calls and queries from visitors to the railway. Someone in this office thought it would be a good idea if there could be a phone at the other 3 stations so a person could lift the handset and be connected directly to the Information Office. As it was not possible to have a direct cable link back from the three remote sites each exchange had an electo-mechanical relay set that dialled a number connect to the office KLU when the associated handset was lifted.
After 3 relay sets had been built and placed in service the office staff decided they didn't have time to answer the calls, a rather short lived exercise and a waste of my time.
Emergency number
2222 terminated on all the Alresford key and lamp units should anyone want access to the emergency services, plug in phone points were provided along the track, the loco crews carrying an emergency phone, with the introduction of mobile phones the need for these reduced and with the provision of exchanges having access to external lines at all stations its need declined further, it was never provided on the Norstar system.