UNIT LEVEL SWITCHBOARD 16

Introduction

The 16 line magneto switchboard is of lightweight and robust construction and has the ability to sustain 16 magneto 'line' extensions and up to 7 'links'. Should further links and extensions be needed it is possible to connect two ULS 16 boards together to allow for up to 32 extensions. The ULS Magneto Unit is almost completely self contained within its own transit casing. The lid (which also features as the unit's base when assembled) contains sufficient space for storage of ancillaries and when placed atop the unit allows for a submersion proof unit.

Links

There are 7 link circuits per Magneto Unit and thus up to 7 conversations between pairs of subscribers can take place at any one time. Conference facilities are available by switching additional subscribers into the link circuit and the maximum number of operators in one conference is limited only by local factors (ie. The signal reduction along the cable, which depends on factors such as quality of cable used, power used and quality of telephone equipment used by each subscriber)

Up to 5 subscribers on D10 line over a distance of up to 5km should provide a decent enough signal quality to allow for good conferencing. However, the Operator of the ULS16 set is able to both monitor and speak on all extensions even when all 7 links are in use.

Unit Layout

1. ON/OFF/TEST Switch - A 3 position switch used in conjunction with the 'Test Meter' and also as a battery power on/off Switch.
2. SOFT/OFF/LOUD Alarm - Allows the operator to set the audible alarm state to that required.
3. Handset - A 7 way socket for the Hand/Headset connection or the connection of a Clansman handset.
4. Link Engaged Indicators - Tells when the links are in use. One per link, black indicates that the link is free and white indicates that it is in use.
5. Test Meter - Used with the on/off/test switch to measure internal/external battery voltage.
6. Call/Clear visual indicators - one pair of green and red disks per subscriber to monitor the status of the connection.
7. Link Key - held up connects to link number 1 and when down connects to link number 2.
8. Link Key - held up connects to link number 3 and when down connects to link number 4.
9. Link Key - held up connects to link number 5 and when down connects to link number 6.
10. Ring Key - when held down sends a ringing current. When held up acts as a link key to link number 7.
11. Speak/Monitor Key - Hold in the up position to monitor and in the down position to speak.
12. Identification Labels - Aluminium plates for recording in pencil the subscriber's identity.
13. External Unit - A 41 way socket allowing for the connection of either an 'exchange unit' or a second ULS16 unit (when used with item 16).
14. External DC - Two spring loaded terminals for connecting an external battery or alternative DC power source (20-33V DC).
15. FS1 and FS2 - A pair of cartridge type fuse holders containing 1 Amp Fuses.
16. External Ringer - Two spring loaded terminals for connecting an external ringer to the circuit. In the event of failure with the internal ringer.
17. Battery Housing - The battery pack is stored under this cover. The battery must be removed when the unit is not in use.
18. Line Term - A 41 way socket to which is coupled the 16 line protection unit.
19. 16 Line Protection Unit - Contains a pair of gas discharge tubes for each pair of lines and 16 pairs of spring loaded terminals for line termination. A captive connector is attached to the 'Line Term' socket on the switchboard. An Earth terminal is also provided to which the Earth Spike braid MUST be connected.

Assembling/Disassembling the Magneto Switchboard

The following are steps to undertake in the setting up of the Magneto Switchboard, follow these in reverse to close it down:

• Release the securing clamps and remove the top from the magneto switchboard transit case.
• Remove from the inside of the lid The Protection Unit, The Earth Spike and the Hand/Headset. Do not remove anything else unless you intend to use it right away.
• Stand the Switchboard into the now upturned cover and secure the mounting brackets. Position the Protection unit atop the switchboard (with the terminals facing towards the rear of the unit) and tighten the captive screws to secure in place.
• Ensure that all the protectors are in place on the protection unit.
• Connect all 41-way cable, attached to the Protection Unit, to the socket marked LINE TERM on the front panel of the switchboard.
• Connect the Hand/Headset
• Connect Each pair of subscriber telephone lines to the terminal pairs on the 16 Line Protection Unit.
• Drive the Earth Spike into moist ground at the nearest convenient point and connect the braid from the spike to the terminal marked 'E'.
• Check that all switches are in the central 'off' position.
• Remove the battery cover from the front of the magneto switchboard by unscrewing the two captive screws, insert a new battery into the coupling circuit and replace the cover how it came off.

THE SWITCHBOARD IS NOW READY FOR TESTING AND OPERATION

Battery Testing

Prior to operation of the ULS16 it's important that we check that the battery is of good enough working condition. To do this we follow the steps below:

1. Set the ON/OFF/TEST stitch to the TEST position. Test meter will indicate the internal battery voltage (for a new battery this should be around 16.5v). This will fall through usage but has a lower operational limit of 10v.
2. If below this (in the red section) the battery must be changed. When storing the unit ensure you remove the battery first.