WEBSTER CHICAGO 79 - Page 11

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
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