Philips SPENDEX 40 Maintenance Manual page 12

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NATO CONFIDENTIAL
S P E N D E X 4 0 U A 8 2 5 1 / 0 0 A N D / O l L I M I T E D M A I N T E N A N C E M A N U A L
3 . 1 . 1 2 V 2 2 b i s m o d e m U A 8 3 4 3 / 0 0
ONLY IN EQUIPMENT TYPE UA 8251/01
The V22bis modem modulates the signal to be transmitted and
demodulates the received signal according to CCITT-recommendation
V22bis.
3 . 1 . 1 3 L i n e i n t e r f a c e b o a r d U A 8 3 1 6 / 0 0
The line interface board contains:
- the line output amplifier
- t h e l i n e i n p u t a m p l i fi e r
- the internal/external modem selector
- the CCITT-V28 modem interface
- the ringing signal detector
- a clear/secure relay
- the external-loop relay
- the 2-wire/4-wire switching relay
- the on-hook relay
- 2 dialling pulse relays
3 . 1 . 1 4 U p p e r c o v e r U A 8 3 0 7 / 0 0
The upper cover covers the upper side of the red compartment of the
housing. In this upper cover also the reed contact of the hook switch
is mounted.
3 . 1 . 1 5 C r a d l e U A 8 3 1 3 / 0 0
The cradle accommodates the handset. The switch arm of the hook
switch is mounted in the cradle.
3 . 1 . 1 6 M a i n s / l i n e fi l t e r ( b a c k c o v e r ) U A 8 3 0 9 / 0 0
T h e m a i n s / l i n e fi l t e r c o n t a i n s :
- the on/off-switch
- the earth connection
- the mains connection with 2 fuse holders
- the line connector
- the modem connector
F u r t h e r m o r e t h e m a i n s / l i n e fi l t e r i s fi t t e d w i t h :
- a transformer panel with 2 transformers which take care of a
galvanic separation with the line;
- a filter plate (line/modem) with feed-through filters for the
signals from and to the line and an external modem;
- a filter plate (battery) consisting of a battery compartment with
feed-through filters for the battery voltage;
- a protection panel (mains) and 2 feed-through filters for the
9 9 2 2 1 5 4 1 3 4 3 1 3 - 4
NATO CONFIDENTIAL