General Telephone & Electronics Leich 40 Service manual

'·
LEICH TYPE 40 AND
TYPE 80 P-A-B-X
r""'r'..... . .- .-~..--:-. ')
~::,·-..;: \
,, ... ~--::..~ ... --- ... i~~; . ~.
'cirra m
' >
.- .~ .... -
. --~-...:-"'-
. .,_, ..
.c,·.
:.s .,_
~'
Technical
Bulletin
500-407
AUTOMATIC ELECTRIC
GE
5N
1
tR~L TELEPHONE & ELECTRONICS G'J&E
TCI Library | www.telephonecollectors.info

Automatic El _ ectric Company General Offices, Laboratories and principal manufacturing facilities
are located in this new 37 acre plant in Northlake, Illinois, a suburb of Chicago. Branch factories are
located in Genoa,
Illinois and Waukesha, Wisconsin.
These modern facilities are devoted exclusively to the manufacture of a complete line of automatic
telephone equipment, electrical control components and systems.
COPYRIGHT © 1964 AUTOMATIC ELECTRIC COMPANY
TCI Library | www.telephonecollectors.info

LE I CH
TYPE
40 AND TYPE 80 P-A-B-X
.. ~• o t
••••
Figure 1. The Type 40 P-A-B-X .
1. INTRODUCTION
This Technical Bulletin covers both the Leich
Type 40 and Type 80 private automatic branch
exchanges, (P-A-B-X). The features and
services provided by these two P-A-B-X's
and the method of operation are very similar.
The principal difference is the capacit y of
each P-A-B-X and the amount of equipment
required to meet the capacity.
The T y pe 40 P- A -B-X (figure 1) is an all relay
switching, common control, and common-
battery type P-A-B-X capable of ser v ing 40
loc al lines (a maximum of 39 lo c al lines w hen
equipped with the attendant's turret). The
Type 40 P-A-B- X operates at a voltage range
of 44 to 56 volts with a common-battery central
office, and can also be adapted to work into a
magneto office. The Type 40 P- A -B- X c an be
equipped with a total of 6 local links, 10 central
offi ce trunks (city trunks), 2 attendant's infor-
mation trunks, and an ,attendant's P-A-X line.
The Type 40 P-A-B-X uses a standard Type
80 or 90 tel e phone a s station apparatus, e xc e pt
in t he case of stations arranged for power
failure transfer service where a Ty pe 80 or
90 telephone equipped with a grounding push-
button ma y be required. Th e Ty pe 40 P- A -B-X
1
TCI Library | www.telephonecollectors.info

uses two-digit lo cal dialing, with single-digit
access to certa in features such as city trunks
or attendant's information trunks. The Type 40
P-A-B-X can be operated with or wit hout the
attendant's turret.
The Type 80 P-A-B-X (figure 2) is an all relay
switching, common control, and common -
battery type P-A-B-X capab le of serving a
maximum of 80 lo cal lines, (a maximum of 79
local lines when equip ped wit h the attendant's
turret). Th e Type 80 P-A-B-X operates at a
voltage range of 44 to 56 volts with a common-
battery central office and can also be adapted
to work into a magneto office. The T ype 80
P-A-B-X can be equipped with 9 local links,
18 c it y trunks (with optional equipment for 3
additional links or 2 additional city trunks),
4 attendant's information trunks, and an attend-
ant's P-A-X line.
The Type 80 P-A-B-X uses standard T ype 80
or 90 telephones as station apparatus with the
exception of stations arranged for power failure
transfer service where a Type 80 or 90 tele-
phone equipped with grounding push- button may
be required. The Type 80 P-A-B-Xuses three
digits for lo cal dialing with single-digit access
to certain features. The Type 80 P-A-B - X can
be operated with or without the attendant's
turret.
The Type 40 and the Type 80 P-A-B-Xhave the
same specified operating limits. The city trunk
loop limit is eit h er the central-office loop limit
or 1500 ohms, whichever is less. The specified
line loop limit is 1000 ohms, excl udin g the
station instrument. At stations assigned to
power failure transfer service, or night answer
service, the sum of the central-off ice trunk
loop and the loop of the P-A-B-X station
assigned to the trunk must not exceed the
central-office loop limit.
2. STANDARD FEATURES AND OPERATING
SERVICES
The following paragraphs outline the standard
features and operating services of the Type 40
and 80 P-A-B-X's.
2 .1 Arranging Trunk Groups
a. The trunks of the Type 40 P- A -B- X can be
split into two groups. The lo c al stations
can then be arranged to fall into one of the
two following classifications :
2
Restricted - local station is restricted from
accessing trunk groups.
Non Restricted - lo c al station ca n ac cess all
trunk groups.
b. The trunks of the Type 80 P-A -B- X can be
split into three groups. Local stations can
then be arranged to fall into one of the three
following cl assifications:
Restricted - local station is restricted from
accessing all three trunk groups.
Non Restricted - local station can access
all three trunk groups.
Partially Restricted - lo ca l station can
access 1 or 2 of the three trunk groups.
2 .2 Trunk Tr ansfer
A local station can transfer a trunk call to a
second local station by dialing the digit "l ",
to place the trunk ca ll on ''hold'', an d then
dialing the digits of the desir ed local station.
When the original local station disconnects,
the trunk call is automatically transferred to
the second local station.
2 .3 Consultation Service
If a local station is engaged on a trunk call ,
dialing the digit ''1'', places the trunk call on
''hold''. The original loc al station can then
dial a second local station and converse with-
out the party on the city trunk being able to
hear the conversation. To return to the trunk
call, after the called station hangs up, the
original station again dials '' l''.
2 .4 Two-Station, One-Trunk Conference Ser-
vice
A two-local station, one-trunk conference
service can be had by connecting a special
''C'' wire at the city trunk. When a local
station desires to bring a second local station
into a conference with a city trunk, he dials the
digit 1, then the digits of the desired local
station. The second station is then informed
not to hang up, the firststationagaindials "1"
to set up the conference.
2 .5 Power Failure Transfer
A number of local stations corresponding to
the number of city trunks can be arranged to
transfer automatically to preassigned c it y
trunks should a commercial power failure
occur. Stations assigned to power failure
service must be equipped with a grounding
push-button when the city trunks are arranged
for outgoing loop dialing with ground seizure
at the distant end. To initiate a call during a
power failure, the grounding push-button at
the local station must be depressed before
the desired party's number can be dialed.
Incoming calls during a power failure are
routed directl y and autom a ticall y from the
c it y trunk to its corresponding preassigned
local station .
TCI Library | www.telephonecollectors.info

Figure 2. The Type 80 P-A-B-X.
2 .6 Universal Night Answer
When the night key (N) on the attendant's
turret is operated, incoming trunk calls will
cause a separate night signal or buzzer on
the turret to sound. The call may be answered
from any local station by dialing the digit
assigned to night answer, usually the digit 8.
If necessary the call can then be transferred
to another local station.
2. 7 Predetermined Night Answering
Certain city trunks can be connected directly
to preassigned local stations when the night
key on the attendant's turret is operated.
In this case the call cannot be transferred
to another local station. Outgoing calls are
originated from these stations as covered
in paragraph 2 .5.
2 .8 Attendant's Busy Override
An attendant, attempting to reach a lo c al
station upon receiving a busy indication, can,
by operating the break-in key (BK), c ut in on
the busy line and inform the desired party of
an important incoming call.
3. OPTIONAL SERVICES
The following paragraphs discuss the optional
equipment that can be incorporated into the
Type 40 or 80 P-A-B-X. Consideration must
be given to the equipment mounting fa c ilities
of either P- A -B-X before adding any optional
equipment. Section 4 covers the various com -
binations of equipment possible with the Type
40 or Type 80 P-A-B-X.
3.1 Code Call Circuit
The code call circuit provides 36 signal codes
which can control audible signals. These
signals are used for notifying parties on the
premises , but out of hearing of their regular
station instrument, that a call is waiting for
them.
3
TCI Library | www.telephonecollectors.info

To sound a particular party's code signal, any
local station or the attendant may dial the digit
assigned to the code call c ir c uit (usuaHy "6"),
then the digits of the desired code signal are
dialed. The longest signal code to be ~ou~ded
is 6 as the 36 codes comprise all combinations
of the digits 1 to 6. To answer, the signaled
part y dials 31 (T y pe 40 P-A-B _ -X) ?r 231
(Type 80 P-A-B-X) from any station; lines 31
and 231 are reserved for code call answer.
A c ode call supervisory lamp which will fla~h
at 60 ipm when the signaled party answers, 1s
mounted on the attendant's turret control panel.
This l am p flashes when the attendant initiates
the code call signal using the attendant out
dial trunk and is required to answer a city
trunk ca ll before the c ode ca ll is answered.
\Vhen a local station uses this circuit , the
lamp will not flash.
3 .2 ''Meet-Me'' Conference Circuit
This circuit provides a ''Meet-me'' type
conference for a city trunk and three local
stations, or four local stations. The attendant
or a lo ca l station can set up a' 'meet-me'' type
co nfer ence involving a ci ty trunk. If a loc al
station is setting up the co nference which
includes a c it y trunk, he di a ls the digit assigned
to meet-me conference service and then re-
places the handset. The c it y trunk is au_tom'.1-
tically transferred to the conference circu i t.
The local station must then notify the other
parties who are to take part in the co nfer e n ce
to dial the number assigned to the conference
c ir cu it. Setting up a ''meet-me'' type c onfer-
ence by the attendant will be discuss ed in
section 8.
3.3 City Trunk Storage
This circuit a llows lo ca l stations to store up
to a maximum of three incoming ca lls when
the attendant's turret is set up for univers a l
night answering service or when an a ttend a nt's
turret is not provided. When an incoming trunk
ca ll is answered by a local station, and an
attempt is made to transfer the ca ll to another
loc al station th e digit 1 is dialed to place the
trunk ca ll on "hold", while the desired party's
number is dialed. If the ca ll ed station is busy,
the call in g station depresses the hoo ksw it ch
a nd notifi es the city trunk party th at hi s party
is busy. If the call in g party desires to wait,
the lo cal station dials the digit 1 and then the
digit assigned to c it y trunk storage . . This
procedure can be repeated to store a maximum
of three ca ll s. To remove ca lls from storage,
the digit or digits assigned to cit y trunk
storage release must be dialed. Calls must be
taken out of storage in the same order they
are placed in storage.
This feature can prove extremely useful; for
e xample a night watchman who cannot rema in
4
at one assigned station, but must be free . to
move ab out to perform various duties. With
this feature he can answer, transfer, hold,
and place calls in storage from any local
station.
3 .4 Executive Override Circuit
This circuit allows an assigned local station
to override a busy condition either automa-
tically · or by dialing a suffix digit. An option
can be provided to supply a ti c k tone to the
busy line so the parties will be aware of the
override condition.
3 .5 Dictation Control Link
This circuit permits the connection of local
stations to centrally located dictation equip-
ment. A dictation control link must be supplied
for each dictation machine provided.
3.6 Public Address Cut-In
Announcements can be made over a public
address system from any local station by
dialing the access number and making the
an noun ceme nt.
3. 7 Paging Telephone
A paging telephone is co nnect ed through a
speaker in a central loc a tion, a microphone
is also located in the same area. This equip-
ment allows a worker to carry on his normal
work, an d maintain a telephone conversation by
listening to the speaker and talking towards the
microphone.
3 .8 Toll Diversion Adapter
This c ircuit adapts an associated city trunk
for toll diversion and toll restriction service.
A local (nonrestri cted ) station attempting to
place a toll ca ll w ill be diverted back to the
atte ndant. The toll diversion a dapter is in-
serted between the trunk circ uit and the ter-
mination of the trunk le a ds to the centra l
office.
3 .9 Tie or FX Trunks
Tie trunks to a distant P-A-B-X or P-B-X
can be provided. Consultation and conference
features can be provided on tie trunks.
FX (foreign exchange) trunks can be furnished
to a central off i ce, other than the central office
serving the P-A-B-X.
3 .10 Rotary Trunk Selection
This circuit provides a max i mum of 2 groups
of 3 lo c a l lines each, 1 group of 5 l oca l li nes
and 1 group of 6 local lines or comb i nations of
TCI Library | www.telephonecollectors.info

these as required and is used to automatically
hunt for an idle line within the group. The
three stations do not h ave to be numbered
consecutively, however, the second digit of
the first pilot number of both groups must
be the same. For example, group one may
be assigned to hunt over lines 41, 56, and
67; and group two may hunt over lines 51,
64, and 72. Notice that the second digit of
the pilot number of the two groups is the same.
3.11 Central-Office Trunk Adapter for 2-Way
Ringdown Signaling
This c ir cuit is capab le of converting a maxi-
mum of three city trunks for 2-way ringdown
signaling.
3.12 Message Waiting Service
Message waiting service can be provided w ith
the Type 40 and 80 P-A-B-X's. To equip a
P-A-B-X for message wa i ting service, a
message waiting turret must be provided
and the telephones served by this message
waiting turret must be equipped with a mes-
sage waiting l amp. The message waiting
turret is similar in design and size to the
attendant's turret. The message waiting
lamp is a neon lamp mounted below and to
the right of the dial.
4. MOUNTING ARRANGE MENTS
The following paragraphs and tables outline
the various equipment mounting arrangements
possible with the Type 40 and 80 P-A-B-X's.
Tables A and C list the standard equipment
provided and also the bank outlets, relay bar
positions · and switch positions required by the
standard equipment. Tables B and D list the
optional equipment that can be provided and
also the bank outlets, relay bar positions
and switch positions required by the optional
equipment.
Th e relay bar shown in figure 3 (link relay
bar) is ready to be jachid-in to its mounting
position. The ja cks are located at the rear
of the metal case. When the re la y bar is
jacked-in to its mounting position, these
jacks will make con tact with the jack strip
lo cated at the mounting position. All relay
bars are equipped with the same type of
metal case and jacks. The metal case en -
c l oses the wiring and various components
mounted at the rear of the re lay bar.
The cross point switch shown in figure 4 can
function as a finder, connector or trunk switch.
The switch must be mounted in the switch shell
before metal contact rods can be inserted.
4 .1 Mounting Arrangements for the Type 40
P-A-B -X
The equipment com prising the Type 40
P-A-B-X is assembled in a three-shelf ar-
rangement and completely enclosed in a metal
cabinet 48" wide, 72" high and 15" deep. The
cabinet is finished in gray lacqu er. The cabinet
has two lift-off type hin ged doors both front
and rear, which when opened allow easy access
to the equipment mounted within (figure 1) .
TABLE A
Eq
uipment
Bank
Switch
Relay Bar
Outlets
Positions
Positions
39 Local l in es: 39
2
link re lay bars
12
2
2 selection control relay bars
2
common equipment
2
1
line equipmen t re l ay strip * -
power failure transfer circuit * -
Atte n dant's turret:
2 atten d ant's information trunks
2 1
turret position
1
turret register **
-
10 city trunks
10 10 10
TOTAL (used) 52 22 18
Balance
8 4 3
*These are relay strips, not jack-in type relay bars.
Their mounting positions
are not considered relay bar positions.
**Turret register circuit is mounted on the power failur e transfer relay bar.
5
TCI Library | www.telephonecollectors.info

TABLE B
Optional Equipment
Bank
Switch
Relay Bar
Outlets
Positions
Positions
''Meet-me'' Conference * 1 3 1
Executive Link
1 1 1
Dictation Control (on line) 1 -1
Dictation Control (on switch)
-1 1
City Trunk Storage 6 -1
Public Address Cut - In **
1 --
Toll Diversion Adapter --1
Code Call 2 -1
* "Meet-Me" conference is mounted on the attendant's trunk relay bar.
**
Public Address Cut-in adapter must be mounted externally.
a. The three equipment shelves are designated
B, D, and E. Shelf B contains the Leich
crosspoint switch shell shown in figure 5,
which houses 6 finder switches, 6 connector
switches, and ten trunk switches. In all,
7
Fi gu re 3. Re lay b ar.
6
the switch shell has available 26 mounting
positions des i gnated Bl through B26.
The finde r and connector switches are
always mounted in pai rs. The number of
L-
I '
r{- ,
.~ ...-
l t...,
,I I
~ ; I ,
~•r ~ ,
, i:......L.,-
,T ;' r
! f ! I
~ . ;_; ·
I t
I
' r
'" '
I "-!
'
I ! I
~
< I
Lr
rl.i
I
Fi gure 4. Cross/Joint swi tch,
TCI Library | www.telephonecollectors.info

these switches required is determined by
the number of links supplied. Each link
requires one finder and one connector
switch.
The trunk switches are mounted to the l eft
and right of the finder and connector
switches. The amo unt of trunk switches
required depends upon the number of city
trunks supp li ed . Each city trunk requires
one trunk switch. The four optional swit ch
positions can be used to house the switches
required by the optional equipment listed
in Table B.
b. Shelf D has available 16 jack-in relay bar
pos i tions designated Dl through D16 (figure
5). Posit ion s D 1 and D2 are occupied by
the two lin k circuit relay bars, each lin k
relay bar conta in s re l ay eq uipm e nt for three
link circuits. Positions D3 through D12
contain the ten city trunk relay bars. If
less than ten city trunks are provided, the
remain in g positions can be used to house
optiona l equ ip ment. Position Dl 3 is occu-
pied by the in terr u pter and the trunk and
code ca ll control circuit. Positions D14,
D15 and D16 are optional positions.
c. Shelf E has 5 j ack-in re l ay bar po s iti ons
designated E l through E5. Pos ition s E6
and E7 house the lin e equipment and pow er
failure transfer circuit; these are not
jack-in relay bar positions (f i gure 5).
Shelf E also contains the fuse panel and
the power supply. Position El is occupied
by the finder guard circuit. Position E2
and E3 are occupied by the selection con-
~
...
CD,
l"Tl~
r
,,
FINDER GUARD El
S ELE CTI ON CONTROL (LIN KS 1- 3) E2
SELECTI
ON CON TROL (LINKS 4-6) E3
ATTENDANTS TRUN KS
E4
AND CON FERENCE
T
URRE T POSI TI ON E5
PO WE R FA ILURE TRAN S FER
T UR RET RE GIST ER
E6
LINES 20 - 50 E7
FUSE PANEL
POWER PLANT
tro l c ir cu it s; each selection co nt ro l re l ay
bar serves three link c ircuits . Position
E4 is oc c upied by the attendant's trunks
and meet-me c onference trunk. Position E5
is occupied by the turret position c ir c uit.
If the attendant's turret is not supplied
this can be used as an optional position.
Position E6 is occup i ed by the power
failure transfer and t urret register c ircuit.
Position E7 is occupied by the lin e e quip-
ment re l ay strip. The line equipment rela y
strip contains 80 rela y s, (40 line relays and
40 cut-off relays) and serves 40 lo ca l lines.
Each local line is served by an individual
line and cut-off re lay.
4.2 Capacity of the Type 40 P-A-B- X
The three factors in determ inin g the over-a ll
equipment capacity of the Type 40 P - A-B-X
are total bank outlets, switch positions, and
re l ay bar positions prov i ded. The Ty pe 40
P-A-B-X provides 60 bank outlets, 26 swit ch
positions and 21 relay bar positions. The Type
40 P-A-B - X shown in figure 5 contains all the
standard equ i pment i nclud in g the equipment
associated with attendant's turret and prov i des
39 l ocal lines , 1 attendant's P-A-X line, 10
city trunks and 2 attendant's information
trunks. Table A lists the capacity of the Type
40 P-A-B-X that h as been utilized.
Table B lists the optional equipment ava ilabl e
for the Type 40 P- A -B-X. When planning the
use of optional equipment keep in mind the
P-A-B-X capacity listed in Table A. T ab l e A
lists the capacity of the P-A-B- X that has
been utilized and also the bank outlets, switch
<J>
:i::
om
r
,,
LIN KS
1-3
LINKS 4-6
TR UNK I
" 2
" 3
" 4
" 5
" 6
" 7
" 8
" 9
" 10
INTERRUPTER,TRUNK
SCO OE C ALL CONTROLS
OP TIO NAL
OPTIONAL
OPTIONAL
TERM. El.. OCKS IN REAR
72"
DI
02
03
04
05
06
07
08
09
010
Oil
012
013
014
015
016
<J>
CD ffl
r
,,
END GUIDE
OPTIONAL
llCONF. 31
T RU NK 9
" 7
" 5
" 3
" I
LINK' F H
LI NK 5 CONNECTOR
LlN K ~ t-lNUt:.H
~TOR
I
TUR
BANK JACK
LINK 2
FIN DER
IN K2
ONNECTOR
LIN K4 FINDER
LINK4
LINKS FINDER
LINK 6
CONNECTOR
£
" 4
" 6
" 8
" IL
(CONF. 2 1
<
CO NF. 4)
EN D GU IDE
B 25
M /S
8 2 1
819
B17 I
B
15
813
RI
89
"'
B5
83
Bl
82
84
B6
tltl
BIO
812
B14
RIIS
B 18
8 20
M N
B24
82 6
__J
Figure 5. Mounting arrangements for Type 40 P-A-B-X.
7
TCI Library | www.telephonecollectors.info

TABLE C
Equipment
Bank
Switch Relay Bar
Outlets
Positions Positions
74 local lines* 74
3
link relay bars 18
3
3
se l ectio n control re l ay bars
3
com m on eq ui pme nt
4
2
line equipment relay strips **
-
power fai lur e tr ansfe r circu it **
-
Attendant's turret: 4
attendant's trunk circuit
1
turret position c ir c uit 1
turret register c ir cuit
***
-
16 city trunk s
18 18
18
TOTAL ( used)
96 36 30
Balan ce
3 4 6
*Lines 286 - 289, 280 strapped for consultation -t ransfer service on city trunks
16-20, may be used for lo ca l lin es if these trunks are n ot u sed.
**These are relay strips, not jack-in type re l ay bars. Th eir mounting posi-
tions are not co n sidered re l ay bar positions.
***T urret register
circuit is mou nt ed on the miscellaneous common eq ui pment
relay bar.
positions, and re l ay bar positions availab l e
for mounting optional equipment. These avail-
ab l e positions wi ll determine the type and
amount of optional equipment that can be used
with this P-A-B-X.
If more optional features are required than
there are optional bank multiple outlets or
sw i tches available, use one of the following
solutions:
a. Decrease one lo ca l line per each bank
multiple outlet required.
b. Decrease one trunk for each switch and
bank multiple outlet required.
4 .3 Mounting Arrangements for the T y pe 80
P-A-B-X
The equipment co mprising the Type 80
P - A -B- X is assemb l ed in a three-shelf ar-
rangement and completely enclosed in a m eta l
cab inet 72" w ide, 72'"' high an d 15" deep (figur e
2). The ca binet has two lift -off hinged doors
and a snap-in ce ntral panel both front and re ar.
The cab in et is finished in gray l acquer.
a. The three she l ves shown in figure 6 are
designated B, D, and E. Shelf B co ntains
the cr osspoint switch shell wh i ch is ca pable
of hou s ing 40 switches and provides 100
ba nk outlets. Th e 40 switch position s within
8
the crosspo int sw it ch are designated Bl
through B40. The crosspoint switch shell
in figure 6 contains 9 finder and 9 c onne ctor
switches, 18 trunk switches, an d 4 optional
switch positions. The amou nt of finder and
connector switches required depends upon
the amount of links supplied. Each link
requires one find er and one connector
switch, these are always mounted side by
side. The amount of trunk switches required
depends upon the number of city trunks
supplied; each city trunk requ ires 1 trunk
switch. The 4 optiona l positions can be used
to house the switches requ i red by the op-
tional equipment list . ed in Table D.
b. Shelf D conta ins 24 jack-in relay bar posi-
tions, designated Dl through D24 (fi gure 6).
Positions Dl , D2, and D3 are occupied by
the three link c ir cuit relay bars, each link
re l ay bar c ontaining re la y equipment for
three link c i rcuits. Pos ition D4 ca n be
occupied either by the link c ir c uit relay
bar c ontaining links 10 through 12 or by
c ity trunk No. 20. If neither of these two
relay bars are provided , this position
ca n be used as an optional position. Posi-
tion D5 is oc c upied by c it y trunk No. 19 if
pro v ided. If trunk No. 19 is not provid e d,
this ca n be used as an optional position .
Positions D6 through D23 are occupied by
city tru nk s No. 1 through No. 1 8. If l ess
than 18 city trunks are pro vided, unused
TCI Library | www.telephonecollectors.info

-~
'~
....
"'=
(I)
J>
(/)
IT1
!
l'TIITI
r
.,,
SELECTION CONTROL NO.I
SELE CTION CONTROL N0.2
SELECTION CONTROL NO. 3
OPTIONAL
OPTIONAL
OPTIONAL
OPTIONAL
ATTENDANT TRUNKS
TURRET POSIT ION
MISC. COMMON
a
TURRET REGISTER
SELECTION ROUTING
FINDER GUARD
FUSE PANEL
(2 6 )
POWER FA ILURE TRANSFER
LINES 211 TO 240
LINES 251 TO 280
TRANSISTORIZED POWER PLANT
12 AMP. BATT . ELIM. 6 CHG .
7 1/2 W. RINGING GEN.
251111 .W. TONE GEN.
El
E2
E3
E4
ES
E6
E7
EB
E9
EIO
E II
E12
E13
E14
EIS
en
:c
OITI
r
.,,
LINKS
1-3
LINKS
4-6
LINKS 7-9
OPTIONAL
OPTIONAL
TRUNK
NO. 18
"
17
"
16
"
15
14
13
TRUNK
N0.12
FUSE PANEL
(26)
TRUNK
NO. II
10
9
e
7
6
5
4
3
2
TRUNK NO.I
INTERRUPTER
a
TRUNK CONTROLS
CJ)
:c
Cill'TI
r
.,,
-
....
DI
.
~
END GUIDE
LINK I FINDER
839
D3
LINK I CONNECTOR
837
LINK 3 FINDER
835
~
LINK 3 CONNECTOR
8-33
LINK 5 FINDER 831
05
LINK 5 CONNECTOR
829
LINK 7 FINDER
827
D6
LINK 7 CONNECTOR
825
LINK 9 FINDER
823
07
LINK 9 CONNECTOR
821
OPTIONAL 819
DB
TRUNK 17 OR OPTIONAL 817
TRUNK N0. 15
815
D9 "
13
Bl3
II
DID
BIi
9 89
DI!
7
B7
5 BS
012 3
B3
TRUNK
NO. I
Bl
BANK JACK
TRUNK
N0.2 B2
Dl3 4
84
6
86
Dl4
8 88
10
BIO
DIS
12
812
TRUNK
N0.14
814
Dl6
TRUNK 16 OR OPTIONAL 816
TRUNK
18 OR OPTIONAL BIB
Dl7
OPTIONAL
B20
822
Dl8
824
Dl9
LINK 8 FINDER
826
LINK 8 CONNECTOR
828
D20
LINK 6 FINDER
830
LINK 6 CONNECTOR
832
D21 LINK 4 FINDE"
834
LINK 4 CONNECTOR
836
D22
LINK 2 FINDER
836
LINK 2 CONNECTOR
840
D23 END GUIDE
D24
72" -------------------------------91
Figure 6. Mounting arrangements for Type 80 P-A-B-X.
9
11
i
i
TCI Library | www.telephonecollectors.info

TABLED
Optional Equipment
Ba nk
Switch
Relay Bar
Outl ets Position
Position
''Meet -m e ' Confe r en ce
1 3 1
Link Relay Bar (links 10-12) -6 1
Link Se le ct ion control re lay bar --1
Code Call
2 -1
City Trunk 1/ 19
1 1 1
City Trunk #20
1 1 1
Executive Link -1 1
Di cta tion Control - trunk on Lin e 1 -1
Di c tation Contro l-trunk on Switch -1 1
C
ity Trunk Storage
6 -1
Public Address Syst em * 1 --
Toll Restriction Adapt e r --1
*P ubli c Address adapter is mounted externally.
positions can be used as o ptio nal positions.
Position D24 is occupied by the interrupter
a nd trunk con trol circu it.
c. Shelf E conta i ns 12 jack-in positions des-
ignated El through E12 (figure 6 ). Positions
E13, E14, and E15 house the line equipment
and pow er failure transfer c ir c uits, these
circu it s are mounted on relay str ips , not
re la y bars. Positions El3, El4, and E 15
are not cons id ered re l ay bar positions.
Pos i tions El, E2, and E3 are occupied by
the three se le ction control c ircuits. A
se lecti on control circuit must be provided
for eac h link relay bar supplied. Position
E4 is occupied by se l ec tion contro l c ir cu it
No. 4, when link s 10 through 12 are pro-
vided. When links 10 through 12 are not
provided, E4 can be used as an optional
position. Pos itio ns E5, E6, and E7 are
op tion a l positions. Posi tion s E8 (4 attend-
ant's trunks), and E9 (attendant's turret),
are associated w ith the attendant's turret
a nd can be used as optiona l positions if the
atte ndant 's turret is not supplied. Position
E l 0 is occupied by the miscellaneous
common and turret register c ircuit. The
miscellaneous common equipment need be
provided on ly if the attendant's turret is
not supplied. Position Ell is occupied
by the selection routing circuit. Position
E12 is occupied by the finder g uard c i rcuit.
Position El 3 is occupied by the power
failure transfer circu it. Positions E14
and E15 are occupied by the lin e equ ipment
relay strips. Each local line is served
by an individual line, and cut -off relay
w hi ch i s mounted on the lin e equ ipm ent
10
re l ay strips. Eac h lin e eq uipm ent re la y
strip conta in s 80 relays, (40 line re la ys
and 40 cut-off relays) and serves 40 loca l
li nes. Therefore two lin e eq uipm ent re la y
str i ps are required to serve 80 local lines.
4.4 Capacity of the Type 80 P-A-B-X
As in the case of the T ype 40 P-A-B-X, the
three fact ors determining the over-all eq uip-
ment capac i ty of the Type 80 P-A-B-X are
the tota l bank outlets provided, switch posi-
tions, and relay bar positions ava il able. The
Type 80 P-A-B-X provides 1 00 bank outlets,
40 switch position s, and 36 relay bar positions.
The Type 80 P-A-B - X shown in figure 6
contains the standar d equipment, in c luding
the equipment associated with t he attendant's
turret and provides up to 79 local lines, 1
attendant's P-A-X line, 18 c i ty trunks, and 3
attendant's inform ation trunks. Table C li sts
the bank outlets, switch positions, and re l ay
bar positions utili zed by this standard eq uip-
ment.
Table D lists the optional equipment available
for the Type 80 P-A-B-X. When planning th e
use of optional equipment keep in mind the
P-A-B-X capacity listed in Table C. Table
C illustrates the capacity of the P-A-B-X
that has been utili zed and also the bank outlets,
switch positions, and re la y bar positions avai l-
able for mounting optional equ ipment. These
available positions w ill determine the type and
amount of optional equ ipm ent that can be used
w ith this P-A-B - X. Also see paragraph 4.5.
When more optional features are required than
there are optional bank mult ipl e outlets or
TCI Library | www.telephonecollectors.info

switches available, apply the following solu-
tions:
a. Decrease one local lin e per each bank
multiple outlet required.
b. Decrease one trunk for each switch and
bank multiple outlet required.
4.5 Type 40 and 80 P-A-B-X A uxiliary Trunk
Bay
The Type 40 and 80 P-A -B- X auxil iar y trunk
bay shown in figur e 7 is designated to be used
as an equipment overflow bay for the Type 40
or Type 80 P-A-B-X. The auxiliary trunk bay
provides 12 jack-in relay bar positions for
mounting optional equipment. With the addition
of the auxiliary trunk . bay, the total relay bar
positions provided by either P-A-B-X is
increased by 12, however, the switch and bank
outlets provided by either P-A-B-X is not
increased.
5. THEORY OF OPERATION
Connection between the ca lling line and the
called line is established through the link
circuit. The link circuit consists of a finder
switch which makes connection to the calling
line under control of the line relay serving
the calling line by way of the finder guard
c i rcu it and link selection c ontrol circuit. A
link relay circuit cons isting of six relays
receives the dial pulses and transmits them
to the associated selection co ntrol circuit. A
connector switch then selects the called line
under control of the link relays and the attached
selection control circuit.
5 .1 Line Equipment
Each local P-A-B-X line is served by a line
relay and a cut-off relay. The line rela y ,
designated LR, operates when the handset is
lifted off-hook and controls seizure of a link.
The cut-off relay, designated CO, operates on
incoming calls to disconnect the line relay
whenever the line is c onnected to a link or
trunk.
5 .2 Finder Guard
The finder guard prevents interference between
lines which attempt to simultaneously land
(seize) by allowing the lowest-numbered line
to land first. The finder guard also provides
a preference circuit to maintain service under
various faulty conditions. If a line has trouble
in landing, a relay will release and shift the
preference circuit so that a high-numbered
line can land ahead of a lower-numbered line
that is in trouble.
0 l~~~•? •~.J"(..jr};; :. f "~ •
::, 0 • O J ,:>
FiguYe 7. Auxiliary trunk bay,
5 .3 Link Selection Control
After a line has landed in the finder guard,
information is passed to the selection control
circuit causing the ca lling line to select an
idle link. Three links are connected to each
selection control and no other links use it;
for example, links 1, 2, and 3 are associated
with selection control circuit No. 1. The link
holds the selection control from the time the
calling party seizes the link and selection
control, until the connection to the called line,
trunk group, or to a special service feature is
complete. The selection control is then dis-
11
TCI Library | www.telephonecollectors.info

engaged from the link, and prepares to accept
another call.
Approximately 8 seconds are allowed for the
calling party to dial the first digit . If no dial
pulses are received within this time, the
selection control causes the link to return
busy tone to the calling party and also ais-
engages itself from that link and prepares
to accept another call. This also holds true
in the case of two-digit numbers for the
maximum time allowed between dialing of
the first and second digits, and also on three-
digit numbers for the maximum time that is
allowed between dialing the second and third
digits.
Incoming calls engage the selection controls
and links in rotation. Assuming that all links
and selection controls are idle, the first call
will seize selection control No. 1 and link 1;
the second call will seize selection control
No. 2 and link 4; in the Type 80 only, the
third call will seize selection control 3 and
link 7. With this condition all three selection
control c ircuits of the Ty pe 80 and the two
selection control c ircuits of the Type 40 have
been utilized and a reset condition occurs so
that the next call that attempts to land will
seize selection control 1 and link 2.
5 .4 Selection Routing
P-A-B-X Only)
Circuit (Type 80
The selection routing circuit is arranged to
absorb the prefix digit of lo cal station codes.
Although the Typ e 80 P-A-B-X uses three-
digit local codes, only two digits are required
to complete a connection through the connector
switch. After absorbing the prefix digit, this
circuit then routes the tens and units digits to
complete the selection. The selection routing
circuit also provides full, partial or non-
restricted service to trunks, and also ro utin g
for special single-digit features.
5 .5 Selection Methods
Both the Type 40 P-A-B-X and the Type 80
P-A-B-X engage a finder switch to find the
calling line and an associated connector switch
to connect it to the called line. Each finder
and connector switch must have access to each
of the 40 or 80 lines served by the P-A-B-X.
A sufficient number . of finder and c onnector
switches should be provided to handle the de-
mands for service during the heavy tr a ffic
hours of the day.
For purposes of example, figure 8 schema-
tically illustrates two finder switches and two
connector switches of a 80-line P-A-B-X.
Only nine of the 80 lines are shown, in order
to present a pictur e of the switch more clearly.
Each lo ca l station is represented by a sing le
12
con ductor, although four conductors are re-
quired in the P-A-B-X for each lin e.
Because the finders and connectors must be
able to access any one line out of the 80
lines, the total lines are divided into tens
selections and units sele c tions, corresponding
to the tens and units digits of the assigned
line number or code. The tens selection selects
that line group which in c ludes the desired line,
a nd the units selection selects one of these
ten lines.
Each switch has 10 tens-lifts, actuated by
armatures associated with the vertical co ils
at the top and bottom of the switch. Eight
of these tens-lifts (10-80) are associated
with line circuits and two (90- and 00) are
available for spe c ial features. To make
a selection, one of these tens-lifts is operated
by its armature to actuate the bank spring
finger into con ta ct with the multiple bars of
ten lines, only three of which are illustrated.
This establishes connections from ten lines
out of the 80, one to each of the ten bank
springs in that switch.
To pick one line out of these ten, eac h switch
ha s ten units-lifts, actuated by armatures
associated with the horizontal coils at the front
of the switch. Operating one of these units-
lifts causes the eleventh, or front finger of the
bank spring on that units level to make contact
with the switch bus conductor.
Assuming that line 31 is ca llin g and that finder
1 is seized for the call, tens-lift 30 in this
finder is operated to connect lines 31-30 to
the bank springs of the swi tc h, and units-lift 1
is actuated to connect its bank spring fingers
to the switch bus conductor. The other nine
bank spring sets do not complete a circuit, as
all potential co nne ctions remain open at the
unoperated units-lift contacts.
Line 31 is now connected to the link associated
with that particular finder. When the desired
number is dialed, the link functions to cause
operation of a tens-lift and a units-lift in the
connector. Ass uming that 23 is dialed, tens-lift
20 functions to connect lines 21-20 to the bank
springs of the connector, thus completing the
connection from the finder by way of the link
and connector to line 23 .
5
.6 City Trunk
The city trunk circuit along with a trunk switch
connects the P-A-B-X to a common battery or
automatic central office. Local stations on
restricted lines can not dial the c ity trunk
di rec tl y to make an outgoing call. These
stations must dial the attendant ov er an attend-
ant's information trunk, a nd ha ve the attendant
make the call for them. These calls can then
TCI Library | www.telephonecollectors.info

31
LINES
32
FINDER I
JO
f\
20
'
ARMTA\NUSRES~
L\f\lE MUL T IPLE
BARS"-
~
"'
21
r.
"'
II
-" "'-
BANK SPRINGS
::;
10
'
CONNEC T OR
30
'
20
'
SWITCH BUS
CONDUCTORS
= ~
"
'
'- \. I I I
=
""
~I
;::::
-"
10
'
"
=~
I
~
FINDER 2
30
r...
20
'
~
=
"' I I
' '
::;
10
'
_=:
~I
CONNECTOR 2
30
'
20
'
IO
r...
,=
~
"'
"'-
I I
~
L ;::::
" A
'
.
~
~I
"
'\.,
'-.,
~
,.,
TO O THER FINDERS
ANO CONNEC TORS
22
'
'-.,
"'
'\.,
,·,
12
'\
~
'
' =
r-,
-=- ' = =-
~2
..
~w ~w
~
~w
=
~
,_
t::;
=
'\.
'\.'
"
'\.
'-.,
I•
23
....
'\.,
,,
"'
'\.,
13
,,;;-
-~
s;;::::; ~
r...,
-=-~
' =:-
>,.
"'-="
I, 3 I 3
'i 3
:3 3
~
1l
'\
~
r
',
l "
13
'
\.
' \ ' '
' '
\.
\
UNITS
ARMATURES
L-----1
LINK
~ ~
LINK
1--
RELAYS RELAYS
Figur e Bo Crosspoint switch diagramo
be extended to th e local sta tiono Stations on
nonrestricted lines may dial the trunk directly
to make outgoing calls.
6 . SELECTION SCHEME BLOCK DIAGRAM
Using the block diagram in figure 9, we will
trace three different types of calls through
a Ty pe 80 P-A-B-X: a call between two local
stations, an outgoing trunk ca ll from a local
station, and an incoming trunk call through the
attendant's turret to a local station.
6 .1 Local Call - Station to Station
For this example, we will assume that station
1 is calling station 2. Station 1 lifts the
handset off-hook which places a d-c loop across
the T and R leads and operates the line circuit
(relay LR). The line circuit actuates the finder ·
guard circuit and identifies the calling line .
The finder guard checks that no other lines are
requesting ,service and signals the first avail-
able link selection control circuit to cause one
of its 3 associated links to connect its finder
switch to station line 1. The link circuit then
signals the line circuit that it has ''found''
the calling line. The line circuit releases the
finder guard and station 1 hears dial tone.
St a tion 1 dials, se ndin g pulses through the lin k
c
ir cu it to the link selection co nt ro l wh i ch
co unts them and pa sses th e information to
the selection routing circuit. The routing
circuit then controls the selection of station
line 2 in the link connector switch. The
selection control circuit tests the line to
determine if it is busy or idle, then signals
the link circuit to return busy tone or switch
through and signal the called station. In
either case, the selection control circuit
disengages from the link circuit and be-
comes available to serve either of its two
remaining associated lines.
6 .2 Outgoing Trunk Call
For this example, we can assume any station
is initiating an outgoing call via a c ity trunk.
The system fun c tions as above (paragraph 6.1)
to the point of tra c ing the ca ll through the
selection routing circuit. In this example, the
s e lection routing circuit recognizes that the
calling station desires to be c onnected to a
trunk circuit, and passes the information to
the access and rotation control circuit (part of
the interrupter and trunk control circuit)
associated with the desired trunk group which
signals the first available trunk circuit to
co nnect itself to the calling line and to re-
13
TCI Library | www.telephonecollectors.info

STA. I
LINIE
Cln'.
FINDER
SW .
LINK-------------
SELECTION
CONTROL
CONN . TRK.
SW. SW .
CKT _____________ __,,
TIIK.
TO DIIT, Ol'C.
TRK. GRP .
ACCESS a
ROTATION
CONTROL
CKT.
ATTENDANTS
TURRET
CITY TRI<.,_ ______ __,
Cl(T.
TURRET
REGISTER
CKT.
POSITION
CKT.
---·----------------------
Figure 9. Block diagram, tracking a call.
lease . the link. If no trunk is available, the
access and rotation control circuit informs
the calling link (via the selection control
circuit) and causes busy tone to be returned
to the ca llin g station. If a trunk is available,
dial tone will be returned to the calling party;
the calling party can now dial the desired city
number.
6 .3 Incoming Trunk Call
On an incoming trunk call, the corresponding
trunk lamp flashes on the a ttendant's turret.
The attendant answers by operating the trunk
switch towards the flashing l amp. The attendant
extends the call, (through the use of the keyset
buttons) via the position ci rcu it, the turret
register circuit, and the selection routing
circuit which act to cause the trunk switch to
perform as a connector switch and connect to
the called station's lin e. The busy test is made
by the position circuit which signals the turret
whether the line is busy or idle. If the line is
idle, the trunk is caused to switch through and
ring whi le the register c ir c uit is released.
7. TRUNK GROUPS A ND RESTRICTIONS
7.1 Type 40 P-A-B-X
a . Restricted and nonrestricted stations. The
Type 40 P-A-B-X is wire d for one tr unk
group, how ever , three trunk groups can be
derived from this one original group. The
14
Type 40 P-A-B-X is wired with all stations
restricted from making city trunk calls.
Local stations, of the Type 40 P-A-B-X,
fall in one of two classifications: restricted,
or nonrestricted. Restricted stations can-
not complete any city trunk calls. In order
to place an outside call, a restricted station
must dial the attendant and have the attend-
ant place the call. Nonrestricted stations
can access any city trunk group. Local
stations are restricted through jumpers
connected between two terminals on the line
equipment terminal blocks mounted in posi-
tion E7.
b. Digit assignment. The Type 40 P-A-B-X
has 10 access digits that are assigned
(when dialed from loc al stations) as in
Table E.
7 .2 Type 80 P-A-B-X
a. Restricted, nonrestricted and partially re-
stricted stations. The Type 80 P-A-B-X is
wired for one trunk group, with all stations
restricted from accessing this group. How-
ever, three trunk groups can be derived
from this one trunk group. The method of
restricting lines is through the strapping
of specified terminals on the terminal
blocks mounted in the line equipment posi-
tions, E14 and E15. Each local line has a
set of terminals on these terminal blocks.
Local stations fall into one of thre e groups;
restricted, nonrestricted or partially re-
TCI Library | www.telephonecollectors.info

stricted. Local stations th at are classified
as restricted ca nnot se i ze any c it y trunk
groups, th ey must h ave the attendant p-lace
a ll ou tside ca ll s. Stations class ifi ed as
nonrestricted ca n se i ze any tr un k group.
Stations class ified as partially restr i cted
can seize t wo of the trunk groups usually
by dialing the access di gits 4 or 5, but
cannot access the primary trunk gro up .
A
nother optional arra n gement can be de -
rived by strapp in g chan ges at the se l ection
routing c ir cu it w he re a partially restr i cted
station ca n se i ze tr unk group No. 4 only o r
trunk gro up No. 5 only.
b . Digit assignment. The Type 80 P-A-B-X
has 12 access digits that are assigned w hen
di aled from loc al s tations as in Table F.
8. ATTEN DA NT'S TURRET
8 .1 Description - T y pe 40 P- A -B- X
Th e attendant's turretfortheType40P-A-B-X
(figure 10) is assembled in an attractive
TABLE E
Digit
Assignment
1
Busy tone Absorb repeatedly
2 Local stations 21-20
3 Local stations 31-30
4 Local stations 41-40
5 Loca l stations 51-50
6 "
Mee t -me" conference or busy tone
7
City trunk, tru nk group No . 2 or busy tone
8
Universa l night answer or busy tone
9
City trunk, tr u nk group No.
1
0
Atte n dan t
TABLE F
Di gi1 A
ssi g nm c nt
- ·
1
Absorb
1·epeatedly
2 Locz
ll l ines
:J
Bus y to ne
4
Bu sy to ne or trunk gro up No. 2
5
Busy lo ne or trunk gro up No . 2
G
Bus y tone or "n 1ee t-m e" co nf ere n ce
7
Bus y tone or code call
8
Un i versa l night answ er
9 C
it y tru nk
0
Attendant
29
Busy tone
20
Busy tone
----- ~
-:::::----_ -
' l· ~1 ~- -~ -~ --------
' ,,,,,,_- ,, , Gi
/ .. ,,, ,... ,----,
v ~// a:, ·:' /
I ,r I,
r ·, 1/. ,,,, ,
,:/- _,,
«'
. . -----------YJJ
~~
Figure 10 " Attendant's tu rret, Type 40 P-A-B- X"
polysty re ne casing, 11" wide, 9" deep, and 6"
high. The turret is available in three colors,
green, beige or gray and mounts eas i ly on a
desk or table . The turret control panel, sl opes
toward the attendant placing all the controls
within easy reach. The handset mounts on the
side of the turret and is equipped with a
retractile cord and a self-com p ensa ting net-
work.
A lthou gh this turret has been assoc i ated wit h
the Type 40 P-A-B-X it can be us ed with a
Type 80 P-A-B-X that w ill not be supplied
with more than 10 city trunks. However, this
would not be ec onomical if additional trunk s
(mor e than a total of 10) ma y be added in the
near future .
8.2 Description - Type 80 P-A-B-X
The attendant's turret for the Type 80 P-A-B-X
(figure 11) is assemb l ed in an attractive po l y-
styrene cas i ng, 1 6" wide, 1 7" deep, and 8"
high . It is similar in des i gn to the Type 40
P-A-B-X attendant's turret. The turret control
panel, slopes toward the attendant to make all
lamps clear ly visible and place all controls
within easy reach of the attendant. The hand-
set, mounted on the side of the turret, is
equipped with a retracti le cord and a self-
compensating network.
The Type 80 P-A-B-X is constructed so that
two attendant's turrets can be connected to
one P- A -B-X switchboard, if c i ty trunk traffic
be c omes too heavy for one attendant to handle
efficiently. The one restriction, in using two
attendant's turrets, is that all the odd-num-
bered trunks must appear on one turret and all
even-numbered trunks must appear on the
other turret.
15
TCI Library | www.telephonecollectors.info

Figure llo Attendant's turret, Type 80 P-A-B-Xo
8 .3 Busy Lamp Field
On incoming trunk calls, the busy lamp field
aids the attendant in determining whether the
desired local station is bus y or idle. By
depressing a preassigned push button on the
turret contro l panel or operating a city trunk
key the attendant can v isuall y determine th e
cond iti on of any local station , witho ut using
the turret keyset.
The busy l amp field is mounted on the attend -
ant's turret above the control panel. The bus y
l
amp field is availab le in three colors, green,
beige or gray. Cabling is required to the
switchboard. The l in e numbers are engraved
in the face panel, which is finished in the same
color as the housing.
8.3. 1 Busy lamp field, Type 40 P- A -B-X
attendant's turret.
The busy l amp field for the Ty pe 40 P- A-B - X
turret is shown in figure 10 . Each of the 40
local stations has an individu al l amp appearing
in the busy lamp fie ld that will light stead il y
wh
en the corresponding station is bus y. The
busy lamp field can be c ontrolled through a
spare push button, designat ed SP, mounted
on the attendant's turret or by operating a
city trunk key. When the push button is de-
pr essed or the c it y trunk key operated, any
busy stat ion will cause its corresponding
busy lamp to light. The lamps are arranged
in four rows of 10 lamps each.
8.3.2 Busy l amp field, Type 80 P- A -B-X
attenda nt's turret (figure 11).
Each of the 80 local stations has an individual
l amp appear in g in the busy l amp field that will
16
li g ht whenever the corres pondin g station is
busy. The busy lamp field ca n be controlled
through a push button, design ate d SP, mounted
on the control p ane l, or by operating a c it y
trunk key. When the push button is depressed
or the c it y trunk key op erated any busy station
w ill cause its busy la m p to ligh t. The l am ps
are arranged in two groups of four rows, w ith
ten lamps in each row. Th e last two digits
of the line's three digit number are engraved
on the face p ane l.
8 .4 Operation of Attendant's Turret
Th e following p aragrap hs outline briefly the
p roper method of operating the attenda nt's
turret. (A c ompl ete set of operating in-
structions is pro v id ed with the P - A -B- X. )
The contro l panels for th e two turrets are
s hown in figures 12 and 13.
a. In com in g trunk ca ll. To answer an in-
coming trunk ca ll , operate the trunk key
toward the fl ashing lamp. Th e lamp wi ll
extinguish and the keyset lamp will light
steadily to indi cate the keyset is availab l e.
b. Signaling a lo ca l stationo To extend the
trunk call to any lo cal station, depress the
keyset buttons in the sequence correspo nd-
ing to the desired station's number. If an
error is made in depressing the keyset
buttons , depress the keyset re l ease button,
designated KR, a nd aga in depress the key -
set buttons corresp onding to the d es ired
local station. If the local station is idle, the
keyset lamp wi ll exti ngui s h, and th e trunk
lamp fl ashes r i nging s i gnal. The trun k key
may then be restored. When the ca lled
station answers, the trunk l amp wi ll light
steadi l y; when the local station disconnects,
th e l amp w ill extingu i sh .
If the call is not answered within a reason-
able time, the attendant can re-enter the call
by reoperating the trunk key. To re l ease
from the c it y trunk, depress the keyset
release button.
If the ca lled local station is bus y, the
keyset lamp will flash and the attendant will
receive busy tone. To re l ease from the
busy connection, depress the keyset release
button. When th e keyset lamp lights
steadi ly , the c it y trunk ca ll can be extended
to another local stat ion if so desired.
c. Busy override. Th e attenda nt can override
a busy condition if necessary to notify one
of the parties of an in com ing trunk call.
By depressing the break-in button, desig-
nated BK, the attenda nt ca n converse with
the parties on the busy line. If the ca lled
station agrees to accept the call, the attend -
ant must depress the keyset release button
and resignal the desired stat ion.
TCI Library | www.telephonecollectors.info

EVEN
TRUNK LAMPS
ODD
TRUNK LAMPS
NIGHT SERVICE -N
CITY
TRUNKS
BBBBB
SP LIT
TO EXT
K
EY 8 DIAL READY
LAMP
(W HITE)
DIAL
FU SE A LARM LAMP
(RED)
TOGGLE SW
ATTENDANTS
PAX LINE
GJ GJ □ GJ [:] ®
PAX N
GJ[JGJ □ [J
CODE CALL ATTENDANTS
NIGHT ALARM
BUZZER
BUT TON DESIGNATIONS
SP DENOTES SPARE.
SK DENOTES BREAK-IN BUSY OVER -RIDE.
HD DENOTES CITY TRUNK HOLD.
DR DENOTES DIAL RELEASE.
KR DENOTES KEY SET RELEASE.
Figure 12 0 Type 40 attendant's turret, control panelo
d . Splitting a call. If the attendant wishes to
converse with the party on the city trunk
without being heard by the local station,
the attendant operates the SPLIT TO TRK
key. Should the attendant desire to talk to
the local station without being overheard
by the city trunk party, the attendant
operates the SPLIT TO EXT key. In both
cases, the trunk key must also be operated.
e. Placing a city trunk on hold. To place a
city trunk call on hold, the corresponding
trunk key must be operated and the hold
key, designated HD, must be depressedo
The keyset lamp will extinguish and the
corresponding trunk lamp will flash. The
city trunk key can then be restored. To
release a city trunk on hold, operate the
trunk key and depress the keyset release
button; the keyset lamp will light and the
trunk lamp will extinguish. If a party on a
city trunk wishes to talk to more than one
local station after depressing the keyset
buttons corresponding to the desired local
station, depress the hold button. The trunk
lamp will flash until the local station
answers, it will then light steadily. When
the local station disconnects, the trunk lamp
will begin to flash, the attendant then de-
presses the keyset release button and then
signals the second local station by depress-
ing the corresponding keys et buttons.
f. Outgoing call via a city trunk. To originate
a call via a city trunk, operate the trunk
key of an idl e city trunk, listen for dial
tone, and then di al the desired city numbero
I£ the city trunk is connected to a manual
office, the operator will complete the con-
nection to the desired city party. To recall
the city operator or release the dialed city
connection, depress the dial release button,
designated DR, holding it down for about
1/2 second.
g. Code call. The attendant places the incom-
ing trunk call on hold by depressing the
hold button and restoring the trunk key.
The attendant then operates the P-A-X key
and using the turret dial, dials the digit
assigned to code call. If the code call
circuit is idle (no busy tone), again by using
the turret dial, dial the code of the desired
party. When the called party answers, by
dialing the digits assigned to code call
answer, the attendant informs the party of
the waiting city call. If the party agrees
to accept the call, the attendant restores the
P-A-X key, operates the city trunk key,
depresses the keyset release button to
release the trunk from hold, and extends the
call to the local station through the keyset.
This prevents tying up the code call circuit.
ho Attendant's information trunks. Two infor-
mation trunks are provided on the Type 40
17
TCI Library | www.telephonecollectors.info

EVEN
TRUNK LAMPS
TRUNK
KEYS
000
TRUNK LAMPS
--~-~--~-~-~--..__......__.....__-::::============---j~ KEY 8 DIAL READY
LAMP(WHITE)
BBGBB
NIGHT SERVICE N
TOGGLE SW
[J8[JGJGJ
ATTENDANTS
PAX
PAX LINE
0 □□ 00
B
®
MON
DIAL
FUSE ALARM
LAMP
(RED)
RESTRICTED NIGHT SERVICE
TOGGLE
SW
CODE CALL
LAMP
(AMBER)
ATTENDANT
KEYSET NIGHT
ALARM
BUZZER
BUTTON DESIGNATIONS
SP DENOTES SPARE.
BK DENOTES BREAK-IN BUSY OVER-RIDE.
HO DENOTES CITY TRUNK HOLD.
DR DENOTES DIAL RELEASE.
KR DENOTES KEYSET RELEASE,
Fi gure 13. Type 80 att end ant 's tur re t, control panel.
P- A -B- X, three are pro v ided on the Type 80
P- A -B- X to allow the atte ndant to receiv e
ca lls from extension stations. When a local
station dials the digit ass igned to inform a-
tion, the inform atio n trunk lamp will flash.
To answer, oper ate the information trunk
ke y toward the flashing l am p. If a lo ca l
stat ion desires in forma tion wh ile conn ec ted
to a c it y trunk, a c onsult a tion ca ll ca n be
made to an infor mation trunk. Wh il e a
c
it y tru nk is on ho ld, th e normal bright,
trunk lamp sup erv ision ch anges to dim
to indicate th e ho ld co ndition .
i .
''Meet-me'' c onferen ce. To c onnect th e
c
it y trunk to the s onference c ir c uit, depres s
the
keyset button corres ponding to the digit
ass igned to co nf erence. If the co nferen ce
ci r c uit is idl e , the c it y trunk w ill be auto -
matica ll y connecte d to it, restore th e c it y
trunk key. Th e attendant must then n ot if y
a
ll the loca l stations w ho are to take p art in
the confere n ce to dial the digit assigned to
the co nferen ce. T h e c i ty tr unk l a mp wi ll
flas h unti l the fi rst l oca l sta tion is c onne cted
to the co nf ere n ce c i r c ui t. If a ft er the con-
18
ference is complete should the c ity trunk
party w ish to c onverse with another lo ca l
stat ion, pla ce the c it y trunk on hold,
operate the c it y trunk key, depress th e
k
ey set rel ease button, depress th e k eyset
buttons correspo nding to the d es ir ed lo ca l
station, and re l ease the ci ty trunk key.
j. Monitoring a busy lin e. To monitor a ca ll
in prog ress on a c it y trunk, op era te the
c i ty trunk k ey a nd a lso the monito r key,
designated MON. The atte ndant can monitor
the ca ll , but ca nnot c onverse wit h out re-
l eas ing the monitor key.
k. Nig ht servi ce. Operate the ni ght key,
designated N, so that in c oming trunk ca ll s
w
ill sound the n igh t signa ls . Th e in com ing
ca ll ca n be a n swered from any l ocal stat i on
by dialing the d ig it ass ign ed to nig ht
answer .
1. Out di al trunk. By operating th e P- A - X
key, the atte nd a nt h as access to a line over
w hi ch any station or spec ia l servi ce can
be reac h ed by us in g the turret dial.
TCI Library | www.telephonecollectors.info