Advertisement
TTS 26B
Section 3
3 . 1 5 SENDING LOOP SIGNALS. The following provides the Procedure for Sending Loop Signals on a
Loop Circuit (See fig. 3-3a):
ACTION
RESULT
a.
With no power applied to the s e t , check the
It should be on the 100 line of the
%
break scale
position of the m e t e r pointer.
(meter electrical 0 ) . If i t is off adjust the screw
on the front of the m e t e r c a s e to bring i t to this
line.
b.
After adjustment, back off the adjustment
s c r e w slightly to remove mechanic dl contact
between the adjustment screw and the meter
mechanism.
c .
FIRST i n s e r t the 310-type plug of the power
supply patch cord into the 48 VOLT jack of the s e t
observing that the proper tip and sleeve polarity,
and then connect i t to the 48-volt dc supply.
d.
Turn the SEND
PPS
switch to the d e s i r e d
pulse r a t e if the internal oscillator is to be used
a s the source of signals.
If a dial o r other exter
-
nal source i s to be used turn the switch to any
position except P W R OFF.
e.
If the LINE ( E ) and DROP (M) lamps do not
light remove the dc power supply f i r s t , then
change the 310-type plug to the other 48 VOLT
jack, and reconnect the 48-volt dc power supply.
f .
If the internal oscillator is to be used a s the
source of pulses, operate the FUNCTION key to
SEND OSC. If a dial o r other external source o r
pulses i s to be used, r e s t o r e the FUNCTION key
to the SEND
DIAL,
turn the EXT DIAL CIRCUIT
to DIAL RLY
-B&G,
and connect the external dial
o r other source of pulsing to the EXT
DIAL
jack
o r terminals.
g.
Turn the FUNCTION switch to CAL METER.
h.
Turn the FUNCTION switch to CAL VoBREAK.
i.
Turn the FUNCTION switch to SEND AND REC.
CAUTION
When the
TTS
26B i s used to pulse
r e p e a t e r s , c a r r i e r pulsing units, etc.
,
c a r e should be exercised to simulate
the pulsing source in the s y s t e m under
test. In many c a s e s the pulsing source
This completes the mechanic a1 adjustment' of
the meter e l e c t r i c a l 0.
If connection is not made in this sequence a
battery supply fuse may blow.
If t h e wrong
48-volt jack is used diode protection within the
s e t will protect the s e t f r o m damage, but the
s e t will be inoperative in succeeding steps.
This turns the s e t on.
The LINE ( E ) and DROP
(M) lamps should light. If they do light proceed
to step f .
If they do not light proceed to step e.
The lamps should light. If they s t i l l do not, the
s e t i s probably not receiving power.
The internal oscillator pulses at the r a t e d e t e r -
mined in step d.
If
a
dial o r other external
sour.ce i s to b e used a s e r i e s of z e r o s must be
dialed during the calibration procedure.
Adjust the METER CAL control to obtain 0 on
the
70
BREAK
scale of the m e t e r .
Adjust the
ADJ
70
BREAK
control to the desired
%
break as indicated on the m e t e r .
If the dial
i s used to generate the signal, dial a s e r i e s of
z e r o s when adjusting
70
break.
The s e t i s now ready to send pulses a t the
required speed and
70
break.
Except for the
SEND o r SEND AND REC switch, the positions
of other- switches and keys i n the s e t a r e imma-
terial. If the pulse speed
is
changed the $ break
calibration should check.
The procedure up to
this point applies to sending d r y pulses on
a
wet
loop, o r wet pulses o n a d r y loop.
To send d r y
pulses on a wet loop proceed with the remaining
S ~ D S
of this ~ a r a ~ r a ~ h
and fnllnw
N f i b ~ 1
Advertisement
