Summary

This is a retouched picture , which means that it has been digitally altered from its original version.

Licensing

This work has been released into the public domain by its author, Panel Switchman at English Wikipedia . This applies worldwide. In some countries this may not be legally possible; if so: Panel Switchman grants anyone the right to use this work for any purpose , without any conditions, unless such conditions are required by law. Public domain Public domain false false

Summary

This is a photo of a typical Panel office OGT (OutGoing Trunk Test). This OGT has two positions. The position on the left can do complete trunk testing to any number to which it is plugged into, using the bank of pushbuttons shown to enter the dialed number. The position on the right can only dial a fixed test number in this case the busy back number plus it can do voltmeter tests.

During a typical day the OGT can become a very busy place. When stuck senders are traced to specific outgoing trunks that appear faulty they are busied out by placing a make busy plug in the trunk. See photo. There are two trunks busied out.

Shooting trunk troubles can become a time consuming task. Especially on open circuits. Then you had to pull the trunk records and call the MDF of all intermediate offices. Have a frameman put a short across the Tip and Ring of the appropriate pair in the appropriate trunk cable and using the volt meter look for the short. I would generally start at the terminating office to make sure it wasn't a terminating equipment problem then work backwards.

As can be seen in the photo trunk groups are identified by different color strips. Each strip could hold up to twenty trunks. This helped staff find a specific trunk group.

Another important part of the OGT is the transmission level meter which is located in the middle of the OGT (the cream colored device) with its own meter and level switch. On a routine basis all outgoing trunks were manually tested by dialing a special 1000 cycle test number over the trunk. The reading was taken and logged into trunk records and then the trunk was released. If the trunk was too far out of spec. it was made busy for further testing.

The OGT also had phones lines on it (appearing along the bottom of the vertical panels). The lines were used when testing with other switchman or frameman in the local office of a distant office. The phone lines were hooked to a very early form of key system based completely on relay logic.

The frame of the OGT was made out of a beautiful hard wood. After some offices were cut over to newer machines some folks took wooden side panels from the OGT home to build projects. This of course required the approval of the supervisor.