WEBSTER CHICAGO 79 - Page 20

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.
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