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TTS
26B
SECTION 1
Section 1
1 . 1
GENERAL.
1 . 2 T h e Model
TTS
26B
i s a compact pulse sig-
naling t e s t s e t designed to send pulses generated
by e i t h e r a built-in. t r a n s i s t o r i z e d o s c i l l a t o r o r an
e x t e r n a l s o u r c e , and to m e a s u r e the
' 3 6
b r e a k and
speed of the transmitted p u l s e s , o r of pulses
r e c e i v e d f r o m e x t e r n a l s o u r c e s .
The
70
b r e a k of
the p u l s e s transmitted by the i n s t r u m e n t can be
varied over a wide range.
The speed of these
pulses can be varied in seven d i s c r e t e s t e p s .
1 . 3 Signals can be received o r t r a n s m i t t e d on a
loop o r an E&M b a s i s . A s e r i e s of jacks i s provided
for the proper connection to the p a r t i c u l a r c i r c u i t
to be t e s t e d .
Switches and keys p e r m i t the t e s t -
m a n to s e t up testing c i r c u i t s for different combin-
ations of sending and receiving on the b a s i s of
loop, E & M , o r a combination of both signaling
s y s terns.
1 . 4
The
Model TTS 26B may be used a s a pulse
r e p e a t e r o r c o n v e r t e r .
Signals f r o m
an
e x t e r n a l
c i r c u i t may be applied to the EXT DIAL jack o r
t e r m i n a l s and used to o p e r a t e the i n t e r n a l pulsing
r e l a y .
The
OJo
b r e a k of this output signal c a n b e
v a r i e d , and i t can be r e t r a n s m i t t e d on a loop o r
an
%&M
b a s i s .
It c a n be used to control e x t e r n a l
c i r c u i t s such a s voice-frequency signaling c i r c u i t s ,
polar duplex c i r c u i t s , e t c .
1. 5 M e a s u r e m e n t s may be m a d e by connecting
the high impedance m e t e r c i r c u i t to the c i r c u i t
under t e s t e i t h e r d i r e c t l y o r through a low imped-
ance "slave" r e l a y .
The m e t e r s l a v e r e l a y is
p a r t i c u l a r l y useful when testing c i r c u i t s which
have high capacitance o r inductance.
Such c i r c u i t s
might d i s t o r t the pulse wave shape and thereby
r e s u l t i n e r r o n e o u s m e t e r readings if the high
impedance m e t e r w e r e used d i r e c t l y on the c i r
-
cuit under t e s t .
1 . 6 The m e t e r h a s
two
s c a l e s
-
one for m e a s u r -
ing
OJo
b r e a k and the other for pulse speed m e a -
s u r e m e n t s in pulses per second (PPS). The
c o r r e c t s c a l e i s obtained by switching the m e t e r
c i r c u i t to correspond to the selected mode of
operation.
1 . 7 The TTS
26B
may be operated f r o m the
48-volt c e n t r a l office battery o r f r o m a suitable
substitute such as an N E C P S I 0 1
-
In emergen-
cies a heavy duty 45-volt d r y c e l l will supply
adequate power to the i n s t r u m e n t f o r a s h o r t time.
1. 8 The s e t i s contained in an aluminum carrying
c a s e with a removable, hinged cover which inclu-
d e s a s t o r a g e c o m p a r t m e n t f o r c o r d s , s m a l l
t o o l s , and such i t e m s .
1 . 9 A c c e s s o r y c o v e r s a r e available to provide
additional functions which i n c r e a s e the v e r s atility
of the Model TTS 26B.
T h e s e c a n be substituted
f o r , o r o r d e r e d i n place of, the removable cover
which normally is supplied with the s e t .
A
s e p a r a t e d e s c r i p t i o n of e a c h of the cover acces-
s o r i e s i s supplied a s supplementary information.
1. 10 A r e l a y r a c k mounted v e r s i o n of the TTS 26B
is available i n the f o r m of the
TTS
26BDR.
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