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TTS
Section 4
when the
SEND
switch i s in the LINE (M=B&O,
E
=G&O)
position.
Battery and open appear on the
ring and ground appears on the tip of the jack.
4.23 For special applications it may be desirable
to have available means for pulsing the sleeves
of the LOOP jacks.
By turning the SEND turn-
button switch to SLEEVES two different arrange-
ments a r e obtained when the SEND switch
is
in
the SEND LOOP REC LOOP position a s follows:
a. A pulsing open and short condition is
applied between the sleeves of the
SEND
1 and
2 jacks.
b.
A
pulsing open and short condition is
applied between the sleeve of the SEND 2 jack
and the sleeve of the REC LOOP jack.
4.24
PULSE REPEATER AND
PULSE CONVER-
TER
FUNCTIONS.
4.25 External keying circuits m a y be connected
through the EXT DIAL
jack, o r binding posts,
which in turn cause the DIAL relay to follow
the pulses as received
Signals may derive
from external loop or E&M circuits, o r f r o m
an external dial.
4.26 The following functions a r e provided for
each of the DIAL
RELAY
positions of the EX T
DIAL CIRCUIT switch.
A simplified schematic
of these circuits is shown in fig.
3.4.
a. DIAL
RELAY
B&G: Ground is applied
to the tip of the
EXT DIAL
jack through the
relay, and battery i s applied through to the
ring.
This permits dry contact pulsing to
be
received f r o m the external circuit.
b.
DIAL
RELAY LOOP: The winding of
the relay i s connected directly to the
EXT
DIAL jack.
This permits wet contact
pulsing to be received from the external
circuit.
c.
DIAL RELAY M: One side of the relay
winding is connected to ground, and the
other side is connected to
the ring of the
EXT
DIAL jack to receive signals f r o m an
M lead.
d. DIAL RELAY E: One side of the relay
winding i s connected to battery through a
l O O O Q r e s i s t o r , and the other side i s con-
nected to the tip of the
EXT
DIAL
jack to
receive signals from an E lead.
4.27 When the FUNCTION switch i s in the SEND
AND
REG position
and
the
SEND
AND TEST key
switch i s in the
DIAL
position, the signal received
on the EXT DIAL jack is retransmitted through
whichever SEND jacks a r e selected by the SEND
switch.
By turning the FUNCTOIN switch tern-
porarily to the ADJ
O/o
BREAK position,
the
%
break of the signals transmitted by the send
circuit may be controlled and measured.
Thue,
it
is
possible to u s e the s e t as a repeater
with
an
adjustable O/o break, or to convert loop signals to
E&M signals o r vice v e r s a , and also control the
O/o
break of the converted signal.
4 . 2 8 SEND
RELAY
Jack
-
When a cord i s
inserted in the jack marked SEND RELAY, the
tip, ring,
and
sleeve of this cord give immediate
access to the contacts of the SEND relay and
thereby perrnit pulsing external circuits such
as oscillators, etc. , at an adjustable
O/o
break.
All other circuits in the s e t a r e disconnected
from the relay contacts when the SEND RELAY
jack is used.
The position of the SPARK SUP
switch determines whether o r not the spark
suppression circuit
is
a c r o s s the relay terminals.
4.29 Line and Drop Busy Test
-
When the TTS
26B
is
to be used on E&M circuits, i t is desirable to
determine f i r s t if the circuit is idle o r not bus$
before applying any test signals to it. When the
SEND-TEST key is in the TEST L & D position,
and the TWD-L and
TWD-D
key switches a r e in
the THRU
&
MEAS position, the.
E&M
leads of
the LINE and DROP jacks a r e connected through,
and the
LINE
and DROP lamps a r e connected to
the
E
and M leads respectively on the LINE, DROP
jacks and also on the E and M jacks.
When the
lamps a r e lit, an on hook condition on the circuit
under test is indicated.
When the lamps a r e
extinguished, an off hook condition is indicated.
Normally, prior to connection of the TTS
26B
to the circuit under test, both lamps a r e lighted
a s an indication of lamp circuit continuity.
4 . 3 0 Supervisory Signals
-
On hook and off hook
signals may be applied independently toward the
line and drop by means of the TWD-L and TWD-D
key switches. When either of these keys i s oper-
ated to either the ON HK o r O F F HK position, the
associated internal signaling circuits a r e removed
from the line and drop and the desired supervisory
signals a r e applied a s follows:
a.
TWD-L in OFF HK position, applies
battery to the M jack and the M lead or
ring of the LINE jack.
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