WEBSTER CHICAGO 79 - Page 3

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