d. The operator challenges the call to determine if
on when receiving a 570 Hz acknowledge tone.
it is a legitimate release request.
k. The acknowledge tone will cause the Converter
e. Operator depresses the ACCESS pushbutton
to stop sending the release tone and channel 1 will
f. operator unplugs answer cord and two-wire
1. Repeat steps through k above for the remaining
g. The channel is now idle.
7.3 Outoing Call From Converter to Four-Wire
and 6.2 above
a. Two-wire subscriber rings into SB-22( )/PT or
verters f o r proper operation. If any
malfunction is experienced during this
b. operator inserts answer cord from SB-22()/pT
checkout, refer to the maintenance section of
or SB-86()/P into a jack on a channel requesting
this manual for proper troubleshooting
c. Operator plugs two-wire subscriber cord into
jack on an idle channel.
7.1 Incoming Call From AN/TTC-25
d. Operator depresses and holds the ACCESS
a. SERVICE REQUEST indicator indicates
pushbutton and the SEIZE pushbutton.
request-for-service (flag indicator).
e. Operator listens in headset for 570 Hz
b. Night alarm is activated (unless turned off).
c. Operator plugs answer cord from operators
f. After signal is heard, operator releases the
cord circuit on SB-22( )/PT or SB-86( )/P into one of
ACCESS and the SEIZE pushbuttons and listens
the jacks on the channel requesting service (channel
for dial tone.
g. After dial tone is heard, operator depresses and
d. Operator depresses ACCESS pushbutton for
holds the ACCESS pushbutton while depressing the
digit keys corresponding to the number of the four-
e. Operator challenges call to determine the two-
wire party being called.
wire subscriber desired.
h. Dial tone is extinguished after first digit.
f. Operator plugs cord from desired two-wire
i. Ring-back tone is heard in headset after last
subscriber into the freejack on channel X.
digit is keyed (depressed).
g. Operator rings forward to two-wire subscriber
j. Operator releases the ACCESS pushbutton.
utilizing ringer on SB-22()/PT or SB-86()/p.
k. After call is established, operator drops out by
h. When the call is established, operator can
unplugging SB-22( )/PT answer cord from channel
monitor or dropout by removing the answer cord
jack or operating SB-86()/P cord circuit switch to
from channel X.
7.2 Release Procedure (Release From Four-Wire
7.4 Release Procedure From Converter
a. Operator momentarily depresses the ACCESS
a. The SERVICE REQUEST indicator is ac-
pushbutton for channel being released and common
tivated for the channel being released (channel X).
b. The night alarm is activated.
b. Operator unplugs answer cord and two-wire
c. The operator plugs the answer cord from the
subscriber cord. Channel is idle.
SB-22()/PT into the free jack on channel X, or
operates the B-86()/P cord circuit switch to TALK