Bell System Practices 595 Installation and operating instructions

TCI Library https://www.telephonecollectors.info/
BELL SYSTEM PRACTICES
Station Installation and
Maintenance
ADDENDUM C55.162
Issue A, 2-1-55-N
T. P. T. & T. Co.
Provisional
TELEPHONE SET
1. GENERAL
595 TYPE
(DISTANT TALKING SET)
1.01 This provisional addendum is issued to provide
information for the field forces pending the re-
ceipt of a more detailed practice from the American
Company. This addendum should be retained with sub-
sequent issues of the section until notice is given cov-
ering its cancellation or reissuance.
1.02 All sets manufactured after November 1954 are
wired in accordance with the drawings in this
provisional addendum.
ADDENDUM
C55.162
Page 1
TELEPHONE SET
595 TYPE
(DISTANT TALKING SET)

TCI Library https://www.telephonecollectors.info/
Page Z s
>-
NOTE 1: Contact Sequence
Removing Handset
1. cb clOlel before de
2. fg opens
Restoring Handset
1, fg ClOlel
2. de opens before cb
LAMP
HOl.DER
HANDSET
TRANSMITTER
lMICROPHONE)
NOTE 2: Manual Servlu
1. Replace dial with 958· 3
apparatus blank.
2. Move green lead from
"F" to
"RR" on the -net·
work.
592A/B-3
Telephone
Set Connections

TCI Library https://www.telephonecollectors.info/
CONTROL UNIT
TSI
~
'
T3
'
.,
I : 4
"*"
R3
It
sL 2
:»:»Oil I
I
If 11,
~ Jlcu
3
t,ci.z *7ct3
4'[[ 7
IOO.U.f' !()Oj&f' I 75JJ.f'
10
I '.JTlY
R5 ~
I
.. -27011
~
RI
Kl
R&
••
U2 00
II
a2on
IOT
122on1
i
,,
2
r~cz.~t..cz~
-ill
00.U.F IOOM. F I 75,µ.f'
llSV
60 ~
7
ll
..
3
, ..
· ~
•
•
-
['.1TS3
12 .
-!-
Tl
8lK JBl ~
I: - F2 +
l!L
: ;-v-~
I: - Rf'I
lv ~ +
.J,. ·-
BLK
'
, 1o·
.!.!L?e
NI I
o4 3
,I"
2
4
C3
I. 12!ltLI
-.-
KS-14964
"*"
R7 , 41 on
3 2
I•
T~
~(
~Cl.Z
'"j1
'°°" ' 'IOOllF
=
h~
'
~
~ - RZ
BL .
-~
24,000n.
7•
,,!.._
.,!,.
+
~:.= =
T-4
~·
R&
4 I
~
2400n.
:
'
12
*
3=·
'
..),.
Control Unit with KS-14990 Amplifier Schematic
ADDENDUM
C55.162
Page 3
TELEPHONE SET
595 TYPE
(DISTANT TALKING SET)
JI
~
A
I~'-"
c A
lo •
£
F
>---
.!!µ
,.__
.;(. µ
~
K
L
"
"
p
~-"
s .
-
,-- -- -- AMPLIFIER UNIT
A INPUT
e
0
TPUT
H
p
s
IMPUT
RI
12n

TCI Library https://www.telephonecollectors.info/
.. ..
INj l ff
D'81'
C AIJ l l
CORD
~
I
- P...L+-
-'< . I
r-
..
-~- -+-
j
~
;,, I
i ·
-T
G ----+
;,, . I
~,
,;v,fs .• ;,
t
DIAL (7[)
(o """'"'"' -)
5928 c3 T EL . SET
l ~ .t
"' '
l & <.
595A/B -3
6• _
IN TE R · Cc>iV:IECi! CIYS
Dist. Talk Tel. Set Dial with Two Off Normal
Switches Double Potentiometer
ADDENDUM
C55.162
Page 4
4
Pages
TELEPHONE SET
595 TYPE
(DISTANT TALKING SET)
I
rs -1
NeT./ ;, " SWl".< 1
~ ~ [dfr :: :
K S· /1 964·L:Z CONT R OL I/ NI T

TCI Library https://www.telephonecollectors.info/
Copyr ight, 1954, by
Aw.erican Telephone and T
eleg raph Compa ny
Printed in U. S. A.
BELL SYSTEM PRACTICES
Station Installation and Maintenance
SECTION C55.162
Issue 1, July, 1954
AT &T Co Provisional
TELEPHONE SET
595 TYPE
(DISTANT TALKING SET)
1. GENERAL
l.01 This sec ti on covers the de sc ription, use a nd ope ration ,
installation and co nnections , main tena nce, and s upplie s
information perta inin g to the 595A-3 (m anual) and 59SB-3 ( dial )
dis
tant talking telephone set .
1.02 Thi s se t incorporates distan t talking and lo uds peaker
features and may be used on dial or manual individual
central office lines, PBX extensio n stations, and IA or l Al key
telephone syst ems. It is arranged for swit c hing to e ith er the
distant talk f ea tur e and lo udsp ea ker or to the regular te lephon e
set for normal use, as required.
1.03 Th is tel ephone equipment is in s talled only upon iss u-
ance of a service order or other proper authori za tion.
2. DESCRIPTION
2.01 The 59SB-3 (dista nt talkin g) tel ep hone set, as sh own in
Fig. 1, consists of three unit s : The 592B-3 te l ep h c. ne set ,
the 758A-3 loudsp eake r, a nd the KS- 14964 contro l unit.
592-Type Telephone Set
2.02 Th e 592B-3 tele phon e set sh ow n in Fig. 2 co nt a in s th e
r
egu lar tel e ph one set features as well as th e co ntrol and
switch ing a rran ge me nt s for u se when the dis tant talkin g featur e
is
requ ir ed. Th e telephone set ha s the genera l appe aran ce of a
500
-ty pe key telephone set with an assembly consisting of a
l
oudspeake r vol um e control, pilot lamp, control keys, and micro-
phone m ou nt ed in the base .
C55.162
Page 1
TELEPHONE SET
595 TYPE
( DISTANT TALKING SET)

TCI Library https://www.telephonecollectors.info/
!'>928-3
TELEPHONE SET
NCOMING
SERVICE
42A-TYPE
CONN. BLOCK
Fig. I-Complete 595B-3 Telephone Set
10!'>- 12!'> V. AC
COMMERCIAL
POWER SUPPLY---..,

TCI Library https://www.telephonecollectors.info/
Fig. Z-59ZB-3 Telephone Set
TRANSMITTER
( MICROPHONE)
2 .03 The l oudspeaker volume control (VOL) enables the
subsc rib er to contro l th e in co min g lou dspeaker level
only. The tran s mittin g level is co ntroll ed by the amp li fier ga in
control in the KS- 14 964 co ntrol unit and is prese t at the factory.
2.04 The pilot l amp lights in the ON but ton when the button
is pressed to ope rat e the t elep hon e set as a di sta nt
talking facility. The OFF button is used to disconnect the tele-
phone set from the distant talk ing feature and to restore it for
normal use.
2.05
The tran sm itt er ( microphon e) co nsists of a mod ified
Ul r ece iver unit mount ed in a sof t neoprene c ushi on
assembly.
2 .0 6 For add iti onal informat i on pertain i ng to compo nent s of
this tel epho ne set that a re common to a ll 500 -t ype tel e-
phone sets, consult th e sections in the 500-series group .
C55.162
Page 3
T ELEPHONE SET
595 TYPE
( DISTANT TALKING SET)

TCI Library https://www.telephonecollectors.info/
Page ·1
758A-3 Loudspeaker
2.07 The 758A-3 lo udsp eake r is provided to furnish loud -
speaker facilities for the distant talking se t. This loud-
speaker, as shown in Fig. 1, consists of a small speaker ur:it
mounted on a met al chassis which is pr ov ided wi th screw
terminals inside for mounting cord connections. These are en-
closed in a rectangular therm op l as tic housin g and metal grill.
The 5-1/2-foot mountin g co rd is equipped with a wing-type
band for fastening to a 4 2A- t ype co nn ect ing block. The base
of th e speak er is provided with an adhesive-typ e fricti on pad.
KS-14964 Control Unit
2.08 The KS-14964 control unit, as shown in Figs. 3 and 4,
consi s ts of an as s embly of electronic apparatus mo un te d
on a
base approxi mat ely 9-5 /8 in ch es by 7-1/8 in ches . It is
Fig. 3-KS-14964 Control Unit

TCI Library https://www.telephonecollectors.info/
equipped with a removable cover, which is approximately 4
inches in depth and fastens with two captive screws. This cover
has a crinkle finish and is beige grey in color. The base is
arranged for wall or desk mounting. Entrance holes for the
inside wiring cable and power cord are located at the bottom
of the unit, and a terminal strip with screw-type terminals is
provided inside for connecting the inside wiring cable conduc-
tors. A clamp is provided for fastening the cable to the unit.
2.09 Included in the KS-14964 control unit a re the trans-
mittin g and receiving amplifiers (KS-14990 amplifier),
po wer supply, and associated circuits. The power supply fur-
nishes the plate supply for the amplifiers of both receiving and
transmitting circuits , power for the pilot lamp in the telephone
set, and power to operate th e U200 relay. Thi s control unit is
equipp ed with a 6 -foot c or d for con nec tin g it to a 60- cy cle, 105-
to 125-volt commercial power supply. This unit will not operate
on direct current.
Fig . 4- KS-14964 Control Unit (Open View)
C55.162
P a ge 5
TELEPHONE SET
595 TYPE
(DISTANT TALKING SET)

TCI Library https://www.telephonecollectors.info/
Pa ge G
2.10 The KS-14990 amplifier emp loyed in th e KS-14964 con-
trol unit furnishes both th e receive an d tran s mit ampli-
fication for the distant t al kin g set . Both amplifi er c ir cuits are
mounted on a single plug -in type, plastic card which fi ts into
an elon gated socket in the base of the control unit , see Fi gs. 4
and 5.
3. USE AND OPERATION
3 .01 The 595-type (d istant ta lkin g) telephon e set is designed
for u se on i ndividual line service or with separa tel y
mounted, 6000- se ries keys of IA or lAl key telephone equip-
ments .
TUBE
RETAINER
Fi&.
5-KS-14900 Amplifier
CK-512AX
VACUUM
TUBE

TCI Library https://www.telephonecollectors.info/
3.02 When it is desired to initiate or to answer calls with the
592-type telephone set and not use the distant talking
features, follow the normal telephone procedures established for
handset-type telephones. When this set is so operated the pilot
lamp does not light.
3.03 To Initiate Call on the Distant Talking Set: Let handset
remain in cradle and press the ON button in the tele-
phone set. This button is non l ocking; however, the relay in the
control unit will l oc k in, the pilot lamp will light the ON button,
and dial tone sho uld be heard from the loudspeaker . This oper-
ation is equivalent to normal switchhook action. When dial tone
is heard, proceed to dial the number without lifting the ha ndset.
As the called party answers, adjust the volume control ( VOL)
for satisfac to ry receiving vo lum e.
3.04
Microphone or transmitting volume cannot be controlled
manually by the subscriber. However, best results can
be attained by limiting the distance between th e microphone
and th e m outh to appro x imately 2 fe et. All other standards of
good telephone usage such as a well modulated voice and facing
the telephone microphone apply to the distant talking set. Noisy
locations and those with po or acou stics will also affect the
quality of tr a nsmission .
3.05
To hang up or have the equiv a lent of switchhook oper-
ation at the completion of a distant talking conversation,
the OFF button must be pressed which returns the telephone
set to a norm al cond it ion. The pilot lamp will go out when the
OFF button is pressed.
3.06 To Answer Call, Using the Distant Talking Features:
Pre ss the ON button in the tel ephone set. Since warmup
tim e is ne g li gible, the pilot lamp lights and the co nversation
may commence immediately. Adjust the volume control for
satisfactory receiving volume , then follow the steps outlined in
3.04 and 3.05.
3.07
To Transfer Call From Distant Talking Set To Hand-
set: If durir!g the course of a distant talking conver-
sa tion it is desired to transfer to normal handset use of the
592-type teleph one se t, it is sim ply necessar y to lift the handset.
The re lay in the cont ro l unit will autom a tically transfe r th e
system to normal telephone operat ion and the pilot lamp in the
ON button will go out . The volume control doe s not control the
level to the rec ei ver in the hands et but ope rates on the loud-
speaker only when the tele phon e se t is being used as a distant
talkin g facility .
C55. 162
Page 7
TELEPHONE SET
595 TYPE
(DISTANT TALKING SET)

TCI Library https://www.telephonecollectors.info/
Page 8
3.08 To Transfer From Handset To Distant Talking Set:
If during the course of a normal handset conversation
it is desired to transfer to distant talkin g operation, it is neces-
sary to press the nonlocking ON button before the handset is
replaced on the cradle and to keep the ON button depressed
until the handset is replaced. Then follow the steps outlined in
3.04 and 3.05. Failure to keep the ON button depressed during
the replacement of the handset to the cradle may result in dis-
connects and lost calls.
4. INSTALLATION AND CONNECTIONS
4.01 Before starting installation , check that the commercial
power is ac. If de is encountered , ref er the matter
through regular organization channels to the Engineering De-
partment for advice before proceeding w ith the work.
4.02 To connect the components of the distant ta lking set
use two 44A connecting blocks mounted on a 168B- type
backboard with a lOlC-type cover. Connect the telephone set
cord , the co nt ro l unit wiring cable, in comi ng service e xtens ion ,
or common ringer to the connecting block terminals, as shown
in Fig. 6.
T elepbone Set
4.03 The 592-type telephone set sho uld be located and
mount ed as described in Section C53.153, IA Key Tele-
phone System Installation . The Dl8F cord is equipped with a
s
tay hook wh ich fits 44A c onnecting blocks. Make co rd connec-
tions on th e connecting block terminals as shown in Fig. 6.
Co nn e ct ions for the 592-type te l ep hon e set are shown in Fi g. 7.
4.04
The telephone set cord shou ld n ot be exposed to mois-
ture. If necessary , fasten cord near the connecting
block with a cable clamp to keep it off the floor.
4.05
When indicated on the se rvice order or on other proper
authoriza ti on, re tractile-type cords for the G-type hand-
set ma y be subs tituted for the s tandard handset co rd.

TCI Library https://www.telephonecollectors.info/
TERMINAL
STRIP IN 592 A/B-3
TEL .SET
19 _
1
2_
r - - - - - - ·1
11 _
I
RR 0:>--1-
I ON NETWORKI 20-
1 OF 592A/ B- 3 I
21-
I
TEL SET I
18 -
L _
__ ___ ..J
15
5 0:J--
2 C2P
6_
7
16
-
17 -
10
17
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
Dl8F CO RD i
I
R
G
y
BK I
BL
I
WH
I
BR
-R
I
BR-
GN I
BR-Y I
BR-BK I
BR-BL I
BR-WH
R-GN :
R-Y I
R-BK I
R-
BL
I
CONNECT ING
BLOCK(2-ll44A)
~
/::? '-,
/ /':4' ·1
/
~5
-::'.6 I
-7
'
:=:'.9 '
- 10 I
-3'
-8 I
-<0 1 I
~2
,.
-:'.'.:;'.4
I
..:;;,5 I
.:::::::6
I
7::.7
I
I I
' I
'I
I
' I
I I
I I
I I
I I
'
'I
I I
I I
'
INSIDE
WIR I NG
CABLE
BL
MATE
OR
MATE
GN
MA TE
BR
MATE
SL
MA TE
BL-WH
MATE
BL - OR
MATE
BL -GN
MATE
ll TERM INA L STRIP
KS
-1 4964
I CON TROL UNIT
I NOTE I
NO
TE I D
EN D
E
ADS
THE
CH
1
~ 2 NOTES I: DEA
I
::::: I BALANCE L
I
:: 8 ~~DTl~ jnGA
::
9
~~~ug~~R
AND
ERM-
AS
IG.4.
I
'2' 12 INAL STR IP
I
::; 11 SHOWN IN F
~3
I _ 5
~ 6
Ii;;'OTE I
I
:: 10
NOTE I
' ~
I _1 3
~7
2 STRAP TO
NGER
DUAL
BRIDGE RI
TO INDIVI
LINE .
I R-W I /
/'. 9 ~
: ~Sl RAP
L OUD
8 I I
-iQ - _..,. NOTE 2
9-
G-Y
SP EAKER -
.::_ I
I I I
eD-1
~
r - - -- ,
~
R
~3 BL - SL
21 4
11 ' I I G
;:;: e MATE
I
::'.1 5
~
I I INSIDE WIRE -I
R2FK-3 I
42A
I R
CORD I CONN. I
FROM IAI KEY SYSTEM
~-
Tl ORT
TO LINE FOR INDIV ID U AL
I BLOCK I PER
SD-69207 -0 11 RI O RR
RINGER OR TO COMMON
L- ---~
X WIRING '8'
p\vli:GND.of IATSYS.
.,_II I
RINGER CIRCUIT OF IA
FROM IA
KEY SY5TEM R~ :
OR I AI KEY T EL . SYSTEMS
Y WIRING
PER SD-69207-011 ,.J-1- l
R
Z WIRING lrROM C.0.
OR PB XLINE t :C J
Fig. 6-The 595-Type Telephone Set-Connections

TCI Library https://www.telephonecollectors.info/
Page 10
Note I: Contact sequence
(a) Removing Handaet
(1) cb closes before de
(2) fg opens
(b) Restoring Handset
(1) fg clo se s
LAMP
HO LD ER
TRANSMITTER
CMICROPHONEl
Note 2: Manual serv ice
(a) Replace dial wit h 95A-3
apparat us bl ank
(b) Move gr een lead from "F"
to "RR" on the n etwork
(2) de opens before cb
Fig. 7-The 592-Type Telephone Set-Wiring Diagram

TCI Library https://www.telephonecollectors.info/
Loudspeaker
4.06 The 758A-3 loudspeaker must be installed so that it is at
least 3 feet away from the telephone set. This distance
is necessary to minimize singing or howling in the loudspeaker
when the vo lume is turned up too high. Attach the cord from
the loudspeaker to a 42A-type connecting block located a suf-
ficient distance from the 44A connecting blocks to facilitate
separation of the telephone set and loudspeaker.
4.07 Noisy l oca tions will greatly cut down the effe ctiven ess
of the l oudspeake r and sho uld be avoided. Aiso , caution
th e s ubscrib er against placing ob jects in front of the speaker
and aga inst attempting to mov e the speake r too close to the
telep hone set which contains th e microphone.
4.08 Have th e su b sc riber make a talking test to find the
best location for the loud spea ker. In most cases the sub-
sc riber may be most co mfortable with the spea k er on o ne side
of his desk and the telephone on the other, as sh ow n in Fig. 8.
Fig. 8-General Location for Distant Talking Set
Control Unit
4.09 Do not plug the power cord into the commercial power
supply outlet until all of the connections of the system
are completed.
C55.162
Pag;e II
TELEPHONE SET
595 TYPE
(DISTANT TALKING SET)

TCI Library https://www.telephonecollectors.info/
Page 12
4.10 In locating the KS-14964 control unit be guided by the
subscriber's wishes and the considerations outlined
below:
(a) Avoid locations where the cord to the control unit may
be stretched across an aisle or passageway, or near a
window or other places where the unit may be exposed to
the elements.
(b) Locate the control unit near the location of the 592-
type telephon e set. The maximum allowable cable dis·
tance between the two is 20 feet. In many cases, where
the cable length is extended beyond the 20-foot maximum,
objectionable dial clicks may be heard in the loudspeaker.
(c) Locate so that workman will not be exposed to injury
when working on the unit and where the equipment
will not be exposed to damage.
(d) Locate the control unit near a commercial 60-cycle,
105-
to 125-volt power supply. The power cord is 6 feet
long. This set will not operate on de power.
(e) When the control unit is to be attached to desks or
wall surfaces, be guided by considerations covered in
Secti on C31.145, Subscriber and Telephone Sets, for Indoor
Lo cat ions, In sta llation.
4.11 \Vhen a backboard is required the 147 A, 165A, or other
s uitabl e backboard may be ·Used and attached in the
same ma nner as s ub sc riber set backboards . When attaching the
control unit to t he 165A backboard, center the unit on the back-
board.
4.12 Make co nn ec tions on the terminal strips in the control
unit as covered in Fig. 6. Leave sufficient slack to enable
movement of cable co nductors to different terminals. Fig . 4
shows a method of disposing of balance leads, spare conductors,
and the forming of cabl e conductors on the terminal strips.
4.13 Check that the KS-14990 amplifier is snug in place. Do
not attempt to adjust the ga in control on the ampli-
fiers. The se are set in the factory and should be readjusted
only by properly qualified and equipped maintenance or trans-
mission engineering forces.

TCI Library https://www.telephonecollectors.info/
4.14 Upon completion of the itJstallation work on all of the
units of the distant talking set, plug the cord into the
60-cycle, 105- to 125-volt power outlet and make operation tests.
Test for proper operation of the ON and OFF switches, pilot
lamp, and volume control.
4.15 Make sure that the subscriber or a competent repre-
sentative understands the functions and use of the
system before leaving the subscriber's premises.
S. MAINTENANCE
5.01 When the telephone set, loudspeaker, or control unit
are dirty, clean the external surfaces and remove loose
dust from the interior in accordance with instruction included
in Section C30.012, Station Sets, Cleaning.
5.02
Make a visual inspection of the interior and exterior of
the telephone set, loudspeaker, and control unit for
obvious defects, such as loose, displaced. or broken parts, ob-
struction of moving parts, or the presence of foreign matter
that could interfere with the proper operation of the equipment.
Telephone Set
5.03 The window strip assembly is mounted to the housing
by means of snaps and may be removed by lifting it out
at each end with the point of a screwdriver or other similar
tool inserted under the end of the strip. The spring prong
fasteners of the snap remain captive in holes in the strip.
5.04 If trouble is encountered in the transmitter (micro-
phone). the complete assembly should be replaced. This
would include the neoprene gasket that cushions the unit.
S.05 In order to insure maximum illumination of the pilot
lamp, any accumulation of dirt or film on the end of
the lamp should be removed by wiping with a damp cloth.
S.06 The SIA lamp may be lifted out from between the
spring contact members of the SSA lamp holder by
inserting a small object into one end and forcing the lamp into
the open. 'A/hen replacing the lamp. press the lamp into place
between the contact members with fingers and slip it forward
toward the ON button to insure maximum illumination.
C55.162
Page 13
TELEPHONE SET
595 TYPE
(DISTANT TALKING SET)

TCI Library https://www.telephonecollectors.info/
Page 14
5.07 Key buttons and switchhook plungers shall move freely
without binding or squeaking throughout their entire
travel. If they bind, remove set cover and determine cause of
binding. Clean the following parts with a cloth moistened with
KS-7860 petroleum spirits: key button s and key but t on holes,
plungers and plunger holes, and the switchboard operating
bracket arm shaft. Do not allow petroleum spirits to get on
contacts of contact springs. If binding continues aft er cleaning,
replace
the key buttons or plunger s.
5.08
If SWITCH ARMS squeak, lubricate the bearing sur-
faces on each end of the operating bra c ket arm shaft
with a No. 2, or softer, graphite pencil.
5.09
No field maintenance sh all be perf o rmed on the switch
assembly except the replacement of the switch assembl y
dust cover .
5.10
Feet, er friction pads if pres e nt , sha ll not be cut, worn,
or have foreign matter imbedded in them to an extent
which might scratch the surfaces on which the set is placed.
If necessary, the feet may be cleaned by brushing with a stiff
bristle brush.
5.11 Feet that cannot meet the requirements in 5.10 shall be
equipped with tr iangular friction pa d KS-8035. If the
telephone set is already equipped with friction pads and they
do not me et requir ements, replace with new pads. If a foot is
missing,
replace the set.
5.12 For adjustments, requirements, and general maintenance
information pertaining to C4A ringer s, see Section
(3 1.207, Ringers - ( Type, Maintenance.
5. 13 Fo r inform a tion pertaining to pro c edures for the re -
placement and cleaning of parts of the GIA handset see
Se ct ion C32.275, Handsets, Maintenan ce.
Loudspeaker
5.14 In spect and clean th e 758A-3 loudspe a ker in accordance
with 5.01 and 5.02. Replace any loudspeake r housing s
found chipped or cracked .
5.15
The loudspeaker base is equipped with an adhesive-type
fr ict i on pad . If the a dh es ive is found to have l ost its
effectiveness, and if the friction pad cannot meet the require-
ments in 5.10 or is mi ssing, r ep la ce.

TCI Library https://www.telephonecollectors.info/
Control Unit
5.16 The following work is all that is recommended for field
maintenance of the KS-14964 control unit. Make te sts
and trouble analyses in the following steps :
(1) Check to see whether the co ntrol u nit is connected by
cord to the power supply outlet . The distant talking set
derives its power from the subscri b er's ac power supply and ,
therefore, will not operate during power failures . Howe ve r,
regular telephone service is not so affected and the tele-
phone set may be used in the normal manner.
(2) Press the ON button in the 592-type telephone set. If
the pilot lamp fails to light, test the power supply outlet
with a neon voltage tester or equivalent.
(3) Take appropriate steps to have the subscrib er arrange
for power restoration in the event of a power off con-
dition.
(4) Wh en commercial power is e nt e rin g the control unit
and amplification seems to be deficient in either or both
receiver and transmitter circuits , the complete KS-14990
amplifier should be replaced with a serviceable one to give
a q uick indic ation that th e trouble is in the amp lifi er.
(5) Disconnect the power supply to the control unit each
time the amplifier or its tubes are pulled out of the
sockets. The amplifier is held in place by a retainer as shown
in Fi g. 4, which must be remove d to free the am plifi er .
Extreme care must be exercised in removing the KS-14990
amplifier from its socket in the base of the control unit.
Since the amplifier is mounted on a plastic card, it should
not be ben t in its socket becau se bending may injure the
termin al e nd of the card or t he soc ke t. It is recommended
that the amplifier be g rasp ed by fin ge rs of both ha nds , and,
if necessary, rocked s lightly from side to side while exert-
ing upward pull.
(6)
If c hangin g the amplifier clears the tro uble, tubes from
the changed amplifier should be repl aced, one by one,
with those of the serviceable amplifier to determine which
are bad, if any. Each CK512AX subminiature tube is held
in plac e by a r etai ner which must be lift ed to clear the top
of the tubes a nd bent back sli ghtly to facilitate the removal
of tubes, see Fig. 5.
C55.162
Pa ge 15
TELEPHONE SET
595 TYPE
(DISTANT TALKING SET)

TCI Library https://www.telephonecollectors.info/
Page 16
(7) Anoth er pro cedure c ould follow along the se lines: If
amplification seems to be low in one circuit only , either
the receiving or the transmitting, tubes can be repla ced in
the suspected cir cuit to determin e which is bad.
(8)
In rein se rting the CK512 AX subminiature tub es, orient
them so that the red mark on the tube base faces the
top of the card and the clot near the top end of the s ocket.
5.17 If any of the above st eps do not clea r trouble that
or i ginates in th e con trol unit , repl ace it with a ser vice-
able one.
6. SUPPLIES
6. 01 This section contains replacement parts th at are pecu-
liar to the 595-type (distant talking ) telephone set.
Index Ordering Information and Description
Amplifier Amplifier, KS-14990.
Plastic card with printed circuit and tubes
to amplify receiving and tr ansmi ttin g cir-
cuits.
Appara tu s Blank Blank , Apparatus, 95A-3.
Covers dial opening when tele phone set
is used for manual serv ice.
Co ll ar P-19BS33, Collar.
Sleeve for ON or OFF button .
Contro l Unit Unit, Control, KS-14964.
Comp lete unit that furnishes power to the
distant ta lking set.
Cords Cord, R2FK-3.
Loudspeaker mounting cord.
Cord, Dl8F-3.
Vinyl jacketed telephone mounting cord.
Dial Dial, 7E-3.
Sp ec ial di al for 592B-3 telephone set.
Equal i zer Equalizer, 333A.
Tr an smitter (microp ho ne) equa lizer .