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transmitter distributor (td). Signals received or local transmissions can be monitored on the page printer.
The typing perforator and typing reperforator are devices for preparing tapes on which locally initiated or
incoming tty messages can be stored for future transmission through the td.
COMMUNICATION PATCHING PANELS.—Ttys are provided flexibility by jacks that are used
to terminate all ttys and associated equipment. The jacks are wired in communications patching panels,
usually referred to as tty patch panels. You are able to connect any combination of equipment electrically
by means of patch cords.
The plugs on the patch cords are inserted into the jacks at the front of the panel. These plugs have
three different parts. They are the tip, ring, and sleeve. The tip carries the intelligence signal while the
ring carries the synchronizing (step) or timing signals. The sleeve carries an alarm signal that indicates
(both visually and audibly) a problem to the operator. The problem may be equipment failure, loss of loop
current, or improper patching. Commonly used combinations of equipment are often wired together
within the panel (called normal-through). Individual pieces of equipment are wired on jacks to allow you
to use them alone or in combination.
Tty patch panels also furnish a central point for connecting the dc voltage supply into the tty circuits.
One source of supply can be used for all circuits passing through a particular panel.
RED and BLACK are used on patch panels to identify whether that panel is used for passing secure
or nonsecure information. Red indicates that secure (encrypted) information is being passed through the
panel. Black indicates that nonsecure (unencrypted) information is being passed. Patch panels through
which secure information is passed are indicated by a red sign on the front that has inch high white block
letters that say "RED PATCH PANEL." Panels through which nonsecure information is passed are
indicated by two black signs on the front with inch high white block letters. One sign says "BLACK
PATCH PANEL" and the other "UNCLAS ONLY."
Each panel contains six channels. Each channel has its own series circuit of looping jacks, set jacks,
and a rheostat for adjusting line current. The number of looping and set jacks in each channel varies with
the panel model. Each panel includes a meter and rotary selector switch for measuring the line current in
any channel. There are six miscellaneous jacks. Any tty equipment not regularly assigned to a channel,
may be connected to one of these jacks.
If the desired tty equipment is wired in the same looping channel as the radio adapter used, no
patching is required. But, if the desired tty is not wired in the same looping channel as the keyer or
converter, it must be patched. For example, let's put a tty on channel 1 and a converter on channel 3. If
you want to receive, you must insert one end of the patch cord in the set jack for channel 1 and the other
end in either one of the two looping jacks of channel 3.
In any switching operation between the plugs and jacks of a tty panel, the cord plug must be pulled
from the looping jack before you remove the other plug from the set (machine) jack. Pulling the plug
from the set jack first opens the circuits to the channel, causing all tty messages in the channel to be
interrupted.
WARNING
Removing the set (machine) jack before the looping jack exposes a dangerous
dc voltage on the exposed plug.
Q23. Most Navy tty sets operate at what speeds?
Q24. A receive tty set provides outputs in what formats?
