WEBSTER CHICAGO 79 Operating instructions

BULLET'N 79PO:›8
SERVICE
INSTRUCTIONS
MODEL 79 8t 80
WIRE RECORDER
IAIEBSTER
CHICAGO
5610 Bloomingdale Ave. Chicago 39, III.

SERVICE INSTRUCTIONS
FOR
WEBSTER-CHICAGO
MODEL 79 & 80 WIRE RECORDER
MODEL 80
The Webster- Chicago Wire Re-
corder Model 80 is a complete,
portable wire recorder and play-
back unit, consisting of a wire
handling mechanism, oscillator,
amplifier and speaker, all enclos-
ed in a sturdy, attractive case.
Provision is made for using an ex-
ternal speaker or amplifier- speak-
er ( public address system) if de-
sired. Input connections are pro-
vided for a microphone or for a
high level input, such as a radio
tuner or a crystal phonograph
pickup. Accessories include a
high impedance Crystal Micro-
phone and a Power Cord, stored
neatly in a compartment in the
cover, also two 15 minute and one
30 minute spools of stainless steel
wire mounted on holders in the
cover.
Physical Specifications — 17 3/8" x
11 3/8 "x 17 1/2 ". Weight 27 lbs.
complete.
RECORD- LISTEN
SWITCH
MICROPHONE
VOLUME
CONTROL
1'
TONE CONTROL
ON- OFF SWITCH
RUN- REWIND
CONTROL LEVER
OUTPUT SELECTOR
SWITCH
Fig. 1 — MODEL 80 WIRE RECORDER
MODEL 79
The Webster- Chicago Model 79 is
a foundation unit, consisting of a 42 P090 ASSEMBLY
CHUCK- WIRE SUPPLY SPOOL RECORDER HEAD
complete wire transporting mech- CHUCK CAP 11 X 180 GUIDE PIN
anism, a triple- purpose recording 45 P279
head ( records, erases and plays BUTTON
DRUM NOTCH
back), an oscillator coil, a 15 min-
ute spool of recording wire, and CLIP
an instruction sheet with suggest-
ed circuit diagram. The service
information on the Model 79 is
identical to the service informa-
tion on the mechanical portions
CONTROL LEVER
of the Model 80 as cont ai ne d in 42 X 092
this manual. The unit takes any
standard Armour type recording
spool and will make continuous
recordings up to a full hour. It is
not in itself a complete unit, and TOP PLATE
is supplied to meet the demand 11X 213
for a basic unit by the manufac-
turer, experimenter, amateur and
professional engineer who wishes to build his own wire recorder and player, or to incorporate it in a
public address system, radio, etc.
Physical Specifications — 10 1/2" x 83/4" x 51/2 " ( 31/2" below main plate, 2" above.) Net Weight 10 lbs.
TAKE UP DRUM COVER
ASSEMBLY
11X 181
CLIP RELEASE
TAKE UP DRUM
42 P091
Fig. 2 — MODEL 79 FOUNDATION UNIT

WEBSTER
CH IC AGO
BULLETIN 79P038
MODEL 79 AND MODEL 80
NOTICE TO SERVICE TECHNICIANS
The operating instructions for Models 79 and 80 are contained in the " OPERATING INSTRUC-
TION MANUAL". The service technician should obtain and study the Operating Instruction
Manual before attempting any repairs or adjustments on these units.
INDEX
Page
I MODEL 79 AND 80 WIRE RECORDER
II INDEX
III MECHANICAL SERVICE NOTES
A — To remove from case — Serial Nos. 5000
to 11000 1
B — To remove from case — Serial Nos
11000 up
C — Spools and Head
D — Shaft Settings 1-3
E — Recheck Recording Head 3
F — Wire fails to - tuck-in" 3
G— Wire breaks— end of " rewind" 3
H — Wire runs too slowly 3
I — Motor Drive Tension 3-4
I — Take-up drum will not turn or slips
when recording 4
K — Supply spool will not turn or slips
when recording 4
L — Cam and Rocker Arm Assembly 8
M— Mechanical rattle in take-up drum 8
N — - Wows" and - Flutter" 8
0 — Fouling of wire
P — Brakes
IV
V
8
9
Q — Uneven recording speed 9
R — Wire spills when recording 9
S — Wire spills when rewinding 9
T — Motor control switch 16
U — Noise at beginning of recording 16
LUBRICATION 17
ELECTRICAL REPAIRS AND ADJUSTMENTS
Circuit changes 17-18
A — Will not run 22
B — Speaker field burned out 22
C — Replacing oscillator coil 22
D — Does not record 22
E — Does not erase 22
Page
F — Does not record or erase 22
G— Low recording level 22
VI VOLTAGE AND RESISTANCE DATA 23
VII MICROPHONES 24
VIII REPLACEMENTS PARTS LIST 27-28-29
IX CONDENSED FACTORY TEST
SPECIFICATIONS 30-31
X ILLUSTRATIONS
Fig. 1 — Model 80 Wire Recorder
Fig. 2— Model 79 Foundation. Unit
Fig. 3 — Spool height adjustments
Fig. 4 — Motor position adjustments 4
Fig. 5 — Motor position adjustments
Fig. 6 — Motor position adjustments
Fig. 7 — Motor suspension adjustments 6
Fig. 8 — Motor position settings 6
Fig. 9 — Motor position settings
Fig. 10 — Motor position settings
Fig. 11 — Rear view — Drive mechanism 7
Fig. 12 — Top view — Drive mechanism 7
Fig. 13 — Brakes, Wire pull tension 10
Fig. 14 — Braking mechanism 11
Fig. 15 - 16 — Brakes — Run position 12
Fig. 17 - 18 — Brakes — Run to Stop position 13
Fig. 19 - 20 — Brakes — Rewind position . 14
Fig. 21 - 22— Brakes— Rewind to Stop
position 15
Fig.23 - 24 - 25—Control lever switch
positions 16
Fig. 26 — Amplifier panel — top view 18
Fig. 27 — Amplifier Chassis— bottom view 19
Fig. 28 — Model 80 Circuit diagram 20
Fig. 29 - 30— Record - Listen switch 21
Fig. 31 — Output switch — Position No. 1 . 21
Fig. 32 — Mic. plug connections 24
Fig. 33 — Exploded parts layout 25-26
2
5
5
6
6
WARNING
The Webster- Chicago Wire Recorder is designed to operate on 105-120 Volts, 50-60 cycle
ALTERNATING CURRENT at a power rating of 65 watts. Best results are obtained when re-
cording and playback are made with the same frequency. With 50 cycle supply, the fidelity
will be a little less, since the wire speed will be about 17% less than normal.
NEVER ATTEMPT TO OPERATE THIS RECORDER FROM A DIRECT CURRENT SOURCE OR
FROM A FREQUENCY OTHER THAN 50-60 CYCLES.
11

bVICBSTER
1
CH IC AG 0
BULLETIN 79P038
MODEL 79 AND MODEL 80
MECHANICAL SERVICE NOTES
Model 80 Wire Recorders and Model 79 Founda-
tion Unit mechanisms are accurately adjusted,
lubricated and tested at the factory. However,
adjustments in the field will be necessary if parts
are replaced or specific troubles indicate misad-
justment. The recommended corrections given
should be made only by a qualified radio service
technician. Service parts are available from your
distributor. All parts must be ordered by part
number, model number and serial number, stamp-
ed on the name plate.
A — TO REMOVE FROM CASE
MODEL 80 — SERIAL Nos.
5000 TO 11000
Remove Top Plate. Place small piece of
cardboard under Control Lever ( Fig. 1) so
panel will not be scratched in removing.
Remove knobs ( pull off). Remove 2 screws
and 4 hex nuts holding panel. Take out the
5 wood screws on each side in order to re-
move the unit. Entire unit may then be re-
moved from case by lifting straight up. DO
NOT TAKE OUT COUPLING SCREWS. The
coupling screws are the two hexagon screws
on each side that hold the Mechanical unit
to the Electrical unit. After the entire unit
has been removed from the case, these
screws may be removed if it is desired to
separate the Mechanical unit from the Elec-
trical Unit.
B — TO REMOVE FROM CASE MODEL
80 — SERIAL Nos. 11000 UP
Remove four screws from the bottom of the
case and one from each side. This permits
easy removal of the entire chassis assembly.
The sled type construction protects all work-
ing parts during service operations.
C— SPOOLS AND HEAD
If wire spills over the top or bottom of both
the take-up drum and the supply spool when
recording or rewinding, adjust the stroke of
the recording head by means of the record-
ing head adjusting screw ( illustration 80,
Fig. 11). This screw is reached by removing
the top cover ( Fig. 2) and inserting a screw
driver through the small hole shown in Fig.
11.
D — SHAFT ADJUSTMENTS
If wire spills over the top or bottom on only
the Drum or the Supply Spool, adjust the
proper shaft.
To adjust the height of the Take-up Drum or
Supply Spool shaft, follow the instructions of
Fig. 3. Be sure that there is proper clearance
between the collar and the main plate.
Wire recorders ( Serial Nos. 5000 — 11000)
may be adjusted through the holes provided
in the bottom of the case. Use care in mak-
1

ADJUSTMENTS FOR TAKE - UP DRUM
AND SUPPLY SPOOL CHUCK
Second. Place spool of wire
firmly on Rewind Chuck.
Line up the inside of the
Bottom Flange with the Inside
of the Bottom Flange of the
Take-up Drum.
SUPPLY SPOOL CHUCK
.010 plus . 002
minus . 002
clearance between
collar and main
plate.
SUPPLY
SPOOL
CHUCK
SHAFT
Loosen Nut and
Turn Screw to
Adjust Height
of Chuck Shaft
3
Third. Set Recording
Head Groove so wire
will wind Flush with
the inside of the
Bottom Flanges of
Rewind Chuck and
Take-up Drum.
First. Set inside of Flange Flush
to 1/32" higher than Top Plate.
TAR- UP DRUM
MAIN PLATE
r-r
Allow 1/32" Plus - Clearance
between Cam and Shaft.
ROCKER
CAM FOLLOWER
SET WORM GEAR CENTER OF SCREW
CAM
ALLOW . 002 to . 005
Backlash.
2 SCREWS TO SET GEAR ASSEMB
Suggestion. In lining up the inside of the Flange of the
Rewind Chuck with the inside of the Flange of the Take-up Drum,
it is suggested that a six inch scale be used. The small half inch
wide six inch scale will just fit.
TOP
PLATE
Set same as Supply Spool Collar
DRUM SHAFT
Loosen nUt and Turn Screw
to Adjust Height of Drum Shaft.
Fig. 3 — SPOOL HEIGHT ADJUSTMENTS
08
13GOW (
INV
61
13GOW
8E0d6Z
N11311118

vezieseran
CHICAGO
BULLETIN 79P038
MODEL 79 AND MODEL 80
ing these adjustments in order that the wire
will wind evenly across the hub of the Take-
up Drum or the Supply Spool. The more
even and smooth the wire is wound, the less
danger there will be of spillage. Also wire
wound improperly will cause " Wows - and/
or " Flutter"
E- RECHECK RECORDING HEAD
Recheck the height of the stroke of the re-
cording head after these adjustments. The
groove in the recording head should travel
almost even with the bottom flange of the
take-up drum and spool chuck each cycle.
F - WIRE FAILS TO " TUCK- IN" ON
THE SUPPLY SPOOL AT
THE END OF REWIND
The wire clip on the take-up drum cover
(Fig. 2) is set to give a little jerk as the last
turn of wire leaves the spool during " Re-
wind". This jerk causes the last turn to tuck
into the lower layers of wire on the supply
spool and prevents unravelling. If the ten-
sion is too weak, the wire will not be held
and this tucking will not take place. The
tension of the clip is adjusted by turning the
adjusting screw ( Fig. 2). On a few units
this tension is adjusted by turning the nut.
It is necessary to remove the take-up drum
cover ( Fig. 2) to make this latter adjustment.
G- WIRE BREAKS AT THE END
OF " REWIND"
Too much tension on the clip mentioned in
"F" may cause consistent breaking of the
wire at the end of the rewind. Occasional
breaking at the clip is normal, due to kink-
ing near the end of the wire. Since only a
fraction of a second of recording time is lost
with each break no harm is done. See para-
graph " F" for tension adjustment.
H - WIRE RUNS TOO SLOWLY
Grime may accumulate in the slot of the re-
cording head ( Fig. 2). Dirty or gummy wire,
due to handling, will cause the recording
head to become gummy. This not only will
cause the wire to pull hard through the re-
cording head but will in some cases act as
an insulator and cause " WOWS". Use a fine
stiff brush ( toothbrush) dipped in carbon-
tetrachloride to clean the groove.
STAINLESS STEEL WIRE DOES NOT
NEED OIL OR GREASE ON IT
I - MOTOR DRIVE TENSION
With the motor control lever in " Run" posi-
tion, the motor shaft should press against the
idler wheel ( Fig. 8) firmly but not too tightly.
From 7 to 9 oz. pressure.
The energy from the motor is shifted from the
"Supply Spool" to the ' Take-up Drum" by
actually shifting the position of the motor.
This is accomplished by means of the motor
3

WEBSTER CHICAGO
control lever ( Fig. 2) operating on a cam
attached to the motor control lever.
J - TAKE-UP DRUM WILL NOT TURN
OR SLIPS WHEN RECORDING
Increase pressure of motor shaft against
the idler wheel ( Fig. 10) by bending cam
followers. ( Figs. 4, 5, 6).
Fig. 4 — MOTOR POSITION ADJUSTMENT
BULLETIN 79P038
MODEL 79 AND MODEL 80
K - SUPPLY SPOOL WILL NOT TURN
OR SLIPS WHEN REWINDING WIRE
Increase pressure of motor shaft against the
take-up wheel by bending the cam followers.
(Figs. 4, 5, 6, 10).
Adjustments can best be made by use of a
slotted bar.
4

WEBSTER
CHICAGO
BULLETIN 79P038
MODEL 79 AND MODEL 80
CONTROL LEVER
CAM
TENSION SPRING -------
SPRING BRACKET ___- 74 -7 ttraggiZe
MOTOR
CAM FOL LOWER
NbIra ----- em-
=MBE.
ISSZIM=
r
YOKE LEG
Lr IT)
MOTOR YOKE
' YOKE LEG
YOKE LEGS MUST
MOVE FREELY IN
SOCKETS IN BOTTOM PLATE
L MOTOR YOKE LEGS MUST BE STRAIGHT
Fig. 5 - MOTOR POSITION ADJUSTMENTS
;OUT
I N
TENSION SPRI
MOTOR TENSION
SPRING BRACKET
BEND OUT TO
INCREASE PRESSURE
ON " RUN ". 9 toil OZ AT DRIVE SHAFT
BEND IN TO DECREASE PRESSURE
y}
N. OToR DRIVE AND REWIND CHUCK
BEND IN TO DECREASE GAP BE1WEEN
DRIVE SHAFT AND IDLER WHEEL
BEND OUT TO DECREASE GAP BETWEEN
Fig. 6 - MOTOR POSITION ADJUSTMENT
5

WEBSTER
CH IC AGO
TENSION SPRING
TENSION SPRING BRACKET
BEND DOWN TO INCREASE PRESSURE
BEND UP TO DECREASE PRESSURE
PRESSURE 2 TO 3 OZ
(
CLEARANCE
IA WS UN DRIVE
AID SUPPLY
SPOOL CHUCK.
BULLETIN 79P038
MODEL 79 AND MODEL 80
•••
_ .«.•••
•
r-
.7,
r --
REWIND POSITION
Fig. 7 - MOTOR SUSPENSION ADJUSTMENT
9 TO II St.
FR ESSDRI
ER IVE SHAFT
AGA DIST IDLER
IIHUL -
IDLER WHEEL
AGAINST
"RUN" POSITS°, \ TAXI- UP
DHOW.
Fig. 8
GAP BEIM=
DRIVE SHAFT
ID IDLER
MOULD RE
SAYE WIDTH AS GAP
STRUM DRIVE A ND
SUPPLY SPOOL CHUM
Fig. 9
IDLER WHEEL
SHOULD
JUST
TOUCH
TAKE-UP
DRUM
TO S os.
PR ESSUR
DRIVA sliA FT
T ISE AGA IN ST
S UPPLY SPOOL
DRUM.
CORRECT MOTOR- PULLEY POSITIONS
"ROMID . 50811101
Fig. 10
M.SARAICE
j BETTIE'
t SOLAR MIL
AID TAXI- UP
1 DEUS • ALSO
! IDLER WHEEL
.v .: ED Dim s
SUFI.

WEBSTER CH IMAGO
BULLETIN 79P038
MODEL 79 AND MODEL 80
AFTER ADJUSTING
WORM GEAR ASSEMBLY.
BEND ROCKER ARM
FOR CENTERING IN SLOT,
Fig. 11 — REAR VIEW — DRIVE MECHANISM
IDLER WHEEL ASSBY.
CHUCK - WIRE SUPPLY SPOOL n II X 003
42 P090
TENSION SPRING
46 P130
LEFT BRAKE
SHOE ASSBY.
II X 183
TENSION
SPRING
46 PI31
DRIVE
WHEEL
II X 195
LEFT BRAKE
LEVER
45P522
IDLER LEVER
11 X 179
BOTTOM
BRAKE
CAM
45 P494
TOP BRAKE CAM
45 P495
RECORDER HEAD ASSBY.
II X 180
RIGHT BRAKE
LEVER
45 P521
Cd
CLIP ADJUSTING SCREW
TENSION SPRING
46 P145
TENSION SPRING
46 PI31
TAKE-UP
DRUM
42 P091
RIGHT
BRAKE SHOE
ASSBY.
11X 184
Fig. 12 — TOP VIEW— DRIVE MECHANISM ( Less Cover Plate)
7

IldICES ZTIER
III
CHICAGO
L— CAM AND ROCKER ARM
ASSEMBLY — Mechanical
Noise and Vibration
Check the adjustment of the cam and rocker
arm assembly ( Illustration 87, Fig. 11)
against the take-up wheel drive post ( Illus-
tration 62, Fig. 11). Back lash should be . 002
to . 005. If greater, loosen screws ( Fig. 11)
and re- set. If the gear is loose on the rocker
arm, replace the entire assembly.
M— MECHANICAL RATTLE IN TAKE-UP
DRUM
The push button in the center of the take-up
drum may be loose. Remove the drum top
and solder the push button to the wire clip
lever.
N—" WOWS" AND " FLUTTER"
The most common reason for " wows" is
failure to phase the wire. Always start the
wire with recording head at the top of its
travel. Be sure that there is nothing which
will rub against either the take-up drum or
the supply spool.
Check the wire on the supply spool to see
that it is not wound too tightly. See that the
recording head is moving up and down
smoothly, that slide has not been bent.
BULLETIN 79P038
MODEL 79 AND MODEL 80
See that no grease or oil has been permitted
to get on the drive wheel tire ( Illustration 65.
Fig. 14) or the idler wheel ( Illustration 60,
Fig. 14) or the take-up drum ( Illustration 57,
Fig. 14). Any oil or grease at these points
will cause slippage, which in turn is trans-
ferred to " wow". Clean thoroughly with car-
bon- tetrachloride. " Flutter" may be caused
by roughness in part of the driving train
such as scoring of the take-up drum with a
sharp instrument in removing spilled wire.
Excessive vibration is usually due to getting
something out of alignment, causing " flut-
ter". " Flutter" is very rare and occurs only
when unusually rough treatment has been
given the wire recorder.
0— FOULING OF WIRE
Carelessness is responsible for nearly all
fouling of wire. Should the wire on the take-
up drum or supply spool become very loose,
or fouled badly, cut through the bight, or
where it bellies, and carefully take off the
wire in the reverse direction in which it is
wound on either the supply spool or the
take-up drum.
When the wire has been allowed to get
under the take-up drum, cut the wire so that
the supply spool may be removed, remove
8

WEBSTER
CHICAGO
the cover, carefully cut wire fouled around
brake, brackets or drum and carefully re-
move, unwinding counter clockwise or con-
trary to the direction in which it is wound.
DO NOT pull wire when it is caught on
anything as damage may be done to the
mechanism.
Where the wire has been allowed to get
under the chuck of the wire supply spool,
cut the wire where it goes under, remove
the supply spool, remove the cover, care-
fully cut the wire or wires that may be
around the chuck and remove.
P - BRAKES
A - memory - brake system to control the
feeding of the wire is tied in with the control
lever ( Illustration 59, Fig. 14). When this
lever is moved from its " Stop - position to its
"Run - position, a light brake is applied to
the supply chuck ( Illustrations 55 and 18,
Figs. 14, 15, 16). When the control lever is
returned to the " Stop - position, a heavy
brake is applied to the same chuck and a
light brake applied to the take-up drum.
(See Figs. 17, 18).
When the lever is moved to " Rewind - the
brake is removed from the supply chuck and
a light brake is applied to the take-up drum.
(Figs. 19, 20). Returning it to " Stop" applies
BULLETIN 79P038
MODEL 79 AND MODEL 80
a heavy brake to the take-up drum and a
light brake to the rewind chuck. ( Figs. 21, 22).
Q - UNEVEN SPEED IN RECORDING
With the control lever in the " Run position,
check the brake adjustment on the supply
chuck. ( Fig. 13). If the tension is too heavy,
the wire will feed too slowly with resulting
slow speed.
To adjust the brake, bend the base plate lug
to which the tension spring ( Figs. 14, 15, 16)
is attached. In extreme cases, slightly bend
the brake lever ( Illustration 74, Fig. 14).
When properly adjusted, the upright flange
of the left brake lever ( 74) should be ap-
proximately centered in the slot of the left
brake shoe assembly. ( 67), Fig. 14.
R - WIRE FEEDS TOO FAST AND
SPILLS WHEN RECORDING
This indicates insufficient brake tension on
the supply spool, permitting it to overrun the
take-up drum. Adjust as explained in Figs.
15, 16.
S - WIRE FEEDS TOO FAST AND
SPILLS WHEN REWINDING
This indicates insufficient brake tension on
the take-up drum. Adjust brake on take-up
drum. ( Figs. 19, 20).
9

BRAKES - WIRE PULL TENSION
USE SMALL POSTAL_ÇAI,LS
-3 .18
'
TO MEASURE PULL RESISTANCE
ON WIRE - SUPPLY SPOOL
PLACE SUPPLY SPOOL ON CHUCK
MAKE LOOP IN ENO OF WIRE
(USING SMALL POSTAL SCALE)
PULL FROM POSITION SHOWN \)s t•
Nth \
REWIND
CHUCK
BRAKE
ASSEMBLY
o
,
1
\ /
RECORDING
HEAD MUST
BE AT TOP
OF TRAVEL
ST.ARTING
CHECK WITH
LIGHT BRAKE ONLY_,
•1'
TO MEASURE PULL RESISTANCE ON WIRE
TAKE-UP DRUM
RUN SEVERAL TURNS WIRE AROUND
TAKE—UP DRUM, CUT WIRE OFF OF SUPPLY
:POOL, MAKE LOOP ON END FROM
TAKE—UP DRUM, USE SCALE
AS SHOWN
04,
Fig. 13- BRAKES - WIRE PULL ADJUSTMENT
r
TAKE-UP DRUM
BRAKE ASSEMBLY
08
13GOW
GNV
61
13GOW
8C0d6Z
NI1311118

IDLER WHEEL ASSBY
CHUCK- WIRE SUPPLY SPOOL n 11 X 003
42 P090
TENSION SPRING
46 P130
LEFT BRAKE
SHOE ASSBY.
11 X 183
TENSION
SPRING
46 P131
DRIVE
WHEEL
II X 195
C IF
C- r4 ,
LEFT BRAKE
LEVER
45P522
IDLER LEVER
11 X 179
BOTTOM
BRAKE
CAM
45 P494
TOP BRAKE CAM
45 P495
RECORDER HEAD ASSBY.
I 1 X 180
RIGHT BRAKE
LEVER
45 P521
Fig. 14 — BRAKING MECHANISM
CLIP ADJUSTING SCREW
I •
TAKE-UP
DRUM
42 P091
RIGHT
BRAKE SHOE
ASSBY.
I1X184
TENSION SPRING
46 P145
TENSION SPRING
46 P131
08
13CIOW
CINV 6Z
8C0d6Z
N

CHICAGO
BULLETIN 79P038
MODEL 79 AND MODEL 80
BRAKES
RUN POSITION
LIGHT BRAKE _ . „. 7 BEND FOR HEAVIER BRAKE
BRACKET
BEND FOR LIGHTER BRAKE
SPRING
PULL RESISTANC
ON WIRE
1/2 OZ TO 5/0 OZ
o
REWIND CHUCK
SUPPLY SPOOL
LIGHT BRAKE
BRAKE
FE LT
PAD_
BRAKE
ARM
LUG- CENTER OF SLOT
USE CARE IN BENDING
CAM FOLLOWERS
/' BEND CAM FOLLOWERS
r FOR ADJUSTING LUGS
SERIAL NOS. 5000 TO 17000
BRAKE TO RUN FREE
DRIVE IS ON THIS SIDE
0
TAKE-UP DRUM y
LUG - HOLDS
BRAKE OPEN ,
BRAKE FELT PAD
ARM
Fig. 15 — BRAKES — RUN POSITION ( SERIAL Nos. 5000 TO 17000)
BRAKES
RUN POSITION
LIGHT BRAKE BEND FOR HEAVIER BRAKE
SPRING /1 BEND FOR LIGHTER BRAKE
AND
BRACKIT
PULL RESIR - TANC
ON WIRE
1/2 OZ Tc2 5/e_c≥ .
BRAKE
FELT
PA
BRAKE
A
USE CARE IN
BENDING
CAIA FOLLOWERS
LUGCEN_TER_OF_GLOT.
STOP
BEND CAM FOLLOWERS
FOR ADJUSTING LUGS
LUG HOLDS
pRAKe OPÇe
_
SERIAL NOS. 17000 UP
BRAKE TO_R_UN_Fteg,
DRIVE ISON THIS SITE
o
TAKg:e_p RP
FIRAKE FELT PAD
--BRAKE ARN
Fig. 16— BRAKES — RUN POSITION ( SERIAL Nos. 17000 — UP)
12

WEBSTER
III
PUL L
R
ES IS TAN CE
ON W IR E
4
1/4 OZ
TO
7 I
/2 OZ
FUL LO A
REWIND CHUCK
S UPP LY_ SPOOL
HE AVY BR AK E
SPR IN G
AN D
BRACKET
BEND IN
FOR LE V
BRAKE
BEND OUT
FOR MORE BRAKE
CH ICAO°
BRAKES
BULLETIN 79P038
MODEL 79 AND MODEL 80
RUN TO STOP SERI AL NOS. 5000 TO 17000
BE ND C AM FOL LOWERS \
F
OR ADJUST IN G LUGS
L UG A GAINST OUTSIDE OF SLOT
STO _F.
LUG - CENTER
OF SLOT
•
PULL RESISTANCE
ON WIRE
3/16 OZ TO 5/16 OZ
L IGHT_ BRAKE
A BEND BRACK ET
T
FOR HEAVIER
B RAK E
BE
ND B RACKET
1FOR LIG HT ER
B RAK E
LIGHT
BR AKE
BRA CKET
AN D
SP R ING
US E C ARE 11 BEND I NG
CAM FOLL OW ERS _
Fig. 17 — BRAKES — RUN TO STOP ( SERIAL Nos. 5000 TO 17000)
LI G HT B RAKE
SPRING
AND
BRACKET
PULL RESISTANC
ON WIRE
4 I/40Z TO 7 1/2 OZ
B RAK E
1
BRAKE
FELT
PAD
B RAK E
ARM
USE CAR E IN
BEN D IN G
C
AM FOLL OWERS BEND C AM F OLLO WERS
FO R A DJ US TIN G L UGS --/
BRAUCES
RUM TO STOP - SERIAL SOS. 17000 UP.
. LUG- AGAINST OUTSIDE
OF S LOT
LUG- CENT ER
OF
SL OT
BRAC KE
HE AVY BRAKE
PULL RESISTANCE
ON WIRE
3/16 OZ TO 5/16 02
LIGHT B RAK E
o
TAKE - UP DRUM
BR AK E FE LT PAD
-BRAKE ARM
LIGHT BRAKE
SPRING
AND
, BRACK ET
//r BEND IN F OR LI G HT ER BRA KE
\ ..y BEN D OUT FOR HE AVIER B RAKE
Fig. 18 — BRAKES — RUN TO STOP ( SERIAL Nos. 17000— UP)
13

III
CHICAGO
BULLETIN 79P038
MODEL 79 AND MODEL 80
BRAKE
EEL T
PAD
BRAKE
ARM
USE CARE IN
BENDING
CAM FOLLOWERS
BRAKES
REWIND
LUG HOLDS BRAKE OPEN
.5 rg_e
BEND CAM FOLLOWERS \
FOR ADJUSTING LUG S
SERIAL NOS. 5000 TO 17000
LUG- CENTER
OF SLOT
PULL RESISTANCE
ON WIRE
3/1'i OZ TO 5/16 OZ
L.GHT BRAKE
TAKE-UP DRUM
"'BEND FOR
HEAVIER
' BRAKE
BEND FOR
/7t
! LIGHTER
vd8R AK E
LIGHT
BRAKE
AND
SPRING
BRAKE FELT PAD
BRAKE ARM
Fig. 19 — BRAKES — REWIND ( SERIAL Nos. 5000 TO 17000)
BRAKES
REWIND SERIAL NOS. 17000 UP
NO BRAKE
REWIND CHUCK
DRIVE IS ON THIS SIDE
BRAKE
FELT
PAD
BRAKE
ARM
LUG HOLDS BRAKE OPEN
STOP
USE CARE IN BENDING
CAM FOLLOW E RS
/BEND CAM FOLLOWERS
FOR ADJUSTING LUGS
7 -'
PULL RESISTANCE
ON WIRE
3/16 OZ TO 5/16 OZ
(
LUG- CENTER
OF SLOT
LIGHT BRAKE
o
TAKE-UP DRUM
BRAKE FELT PAD
BRAKE ARM
LIGHT BRAKE SPRING
AND BRAGKEI
/4IEND IN FOR LÉSS BRAKE
\ BEND OUT FOR MORE BRAKE
Fig. 20 — BRAKES — REWIND ( SERIAL Nos. 17000 — UP)
14

WEBSTER
CH ICAGO
BULLETIN 79P038
MODEL 79 AND MODEL 80
REWIND TO STOP SERIAL NOS. 5000 TO 17000
LIGHT BRAKE , BEND FOR LleITER BRAKE
SPRING A- - ", BEND FOR HEAVIER BRAKE
AND
PULL RESISTANC
ON WIRE
1/2 OZ TO 5/8 OZ
LIGHTOBRAKE
REWIND CI4UCK
SUPPLY ._ SPOOL
BRAKE
FELT
PAD
BRAKE
ARM
USE CARE IN
BENDING CAM
FOLLOWERS
BRA.KES,
LUG - CENTER OF SLOT
STOP
/
BEND CAM FOLLOWERS •
(.. FOR ADJUSTING LUGS
US
AGAINST
OUTSIDE
OF SLOT
PULL RESISTANCE
ON WIRE
5 OZ TO 8 1/2 OZ
HEAVY BRAKE
TAKE-UP eaum
BRAKE FELT PAD
BRAKE ARM
HEAVY BRAKE SPRING a BRACKET
8E140 IN FOR LESS BRAKE
• BEND OUT FOR MORE BRAKE
Fig. 21 — BRAKES — REWIND TO STOP ( SERIAL Nos. 5000 TO 17000)
BRAKES
REWIND TO STOP
BENO F OR LISFITER BRAKE •
LIGHT BRAKE..- F
,
BEND OR HEAVIER BRAKE
SPRING
AND
1FR_ACK
BRAKE
FELT
PAD
BRAKE
ARM
PULL RESISTANCE
ON WIRE
1/2 OZ TO 5/8 oz
LIGHT BRAKE
REWIND CHUCK
SUPPLY SPOOL
USE CARE IN
BENDING
CAM FOLLOWERS
LUG. CENTER OF SLOT
STOP
/BEND CAM FOLLOWERS
r\
FOR ADJUSTING LUGS
L UG
AGAINST
OUTSIDE
OF SLOT
SERIAL NOS. 17000 UP
PULL RESISTANCE
ON WIRE
5 OZ TO B 1/2 OZ
HEAVY BRAKE
TAKE-UP DRUM
BRAKE FELT PAD
BRAKE ARM
t BEND IN FOR LESS BRAKE
BEND OUT FOR MORE BRAKE
Fig. 22 — BRAKES — REWIND TO STOP ( SERIAL Nos. 17000 — UP)
15

WEBSTER CHICAGO
BULLETIN 79P038
MODEL 79 AND MODEL 80
T - MOTOR CONTROL SWITCH
With the motor control lever in " Stop" posi-
tion, the switch contacts should both be open
1/ 32 " to V p3 ". When the lever is moved to
"Run" position the motor contacts ( Fig. 24)
should be first to close. In " Rewind" position
the recording head contacts ( Fig. 25) should
remain open.
/ OFF POSITIQN_
BOTH CONTACTS
g_pE tt 1/32" TILLI"
KEEP Cr: WIDE SIDE
U - NOISE AT BEGINNING OF EACH
RECORDING SEQUENCE
If the recording head contacts close before
the motor contacts, the noise of making con-
tact and starting will appear on the wire.
Bend the switch contacts ( Illustrations 72, 76)
so that the motor starts before the recording
head is energized.
BOTTOM VIEW
ED- FROM
-, HEAD SIDE
B
SWITCH a COIL
r.
' YELLOW BLACK
RED - BLACK FROM MOTOR
Fig. 23 — MOTOR CONTROL SWITCH — " OFF" POSITION
SET ONTÇT _ Q ,( ATION WILL NOT AFFECT OPERATION QF swiTcji
BE SURE CONTACTS ARE SET SO MOTOR IS RUNNING BEFORE MOTOR
DRIVE SHAFT CONNECTS WITH . DLER WHEEL OR SPOOL CHUCK
BOTTOM VIEW
MOTOR CONTACT MUST CLOSE FIRST
Fig. 24 — MOTOR CONTROL SWITCH — " RUN" POSITION
BOTTOM VIEW
MOTOR CLOSED
Fig. 25— MOTOR CONTROL SWITCH — " REWIND" POSITION
16

WEBSTER
CHICAGO
BULLETIN 79P038
MODEL 79 AND MODEL 80
LUBRICATION
It is well to lubricate about every six months, or
for every 500 hours of operation. Use a grease,
such as Lubriplate, at the following points.
1 — Sliding surfaces or slide and socket as-
sembly. ( Illustration 52, Fig. 11).
2 — Sliding surfaces of brake cams ( Illustra-
tions 61 and 73, Fig. 14) and control lever
(Fig. 11). Be sure to grease the edges of
the cams where they rub against the
brake levers. ( Illustrations 71 and 73, Fig.
14).
3 — Pivots of brake control levers ( Illustrations
71 and 73, Fig. 14) and brake shoe assem-
blies ( Illustrations 67 and 70, Fig. 14). Do
not use grease in the slots of the brake
shoe assemblies.
4 — Under the idler level assembly ( Illustra-
tion 68, Fig. 14).
5 — On the worm shaft ( Illustration 62, Fig. 11)
where it contacts the gear of the rocker
cam assembly. ( Illustration 87, Fig. 11).
6 — On the outside edge of the cam ( Illustra-
tion 87, Fig. 11).
7 — On the rubbing surfaces of the switch cam.
(Illustration 100, Fig. 4).
USE LIGHT OIL AT THE FOLLOWING
POINTS
1 — Idler ( Illustration 60, Fig. 12) bearing on
felt washer.
2 — On the self- aligning bearings of shafts ( Il-
lustrations 58 and 62, Fig. 33).
3 — Motor bearings.
4 — If new brake shoe assemblies ( Illustrations
67 and 70, Fig. 12) are installed, apply one
drop of light oil to each felt. Otherwise
do not oil these felts.
Be very careful not to allow oil or grease to touch
the rubber surfaces of the drive wheel ( Illustration
60, Fig. 12). Any lubricant on these surfaces
should be removed immediately with carbon tet-
rachloride. Excess lubricant on the brake felts
will cause an oily surface on the supply of take-
up drum. Such oil should be removed with car-
bon tetrachloride.
ELECTRICAL REPAIRS AND ADJUSTMENTS
The oscillator- amplifier circuit of the Model 80 wire
recorder is simple and trouble proof. With the
"Record- Listen" switch in the " Record" position
the 6V6 acts as an oscillator, the 6517 and 6J5 act-
ing as amplifiers. In " Listen" position, the 6V6 acts
in its usual capacity as an output amplifier tube.
CHANGES
Although minor changes and improvements have
been made, four changes have been made in
the amplifier circuit that will affect the service
technician.
17