17. Elevation Handwheel
to indicate distributor shaft revolutions
per minute. It has two scale ranges: 0-500
The elevation handwheel (5), located
and 500-2500 rpm. A tachometer indicator
above the distributor clamp (26), is used
adjustment button (24) located in the center
to elevate and lower the distributor to the
of the dial at the bottom of the gage is
required height for clamping the drive of
used to zero the gage prior to operation
the distributor in the chuck (11). The hand-
of the tester.
wheel is turned clockwise to raise and
counterclockwise to lower the distributor.
14. Dwell Meter
18. Speed Control Handwheel
The dwell meter (2) (identified as "DE-
GREES DWELL" on the dial face) is lo-
The speed control handwheel (15), lo-
cated directly below the tachometer in-
cated to the right center and below the
dicator (par. 13 above) m e as u r es the
stroboscope (12), is used to vary the op-
degree of dwell of the distributor breaker
eration speed of the tester. Turning the
points and is calibrated in degrees from
wheel clockwise lowers the speed at which
0 to 50, with each divisional marking in-
the distributor is being turned and coun-
dicating one degree of cam angle. A dwell
terclockwise increases the speed.
meter adjustment button (23), located in
the center of the dial at the bottom of the
19. Indicator Light
meter, is used to adjust the meter prior
The indicator light (16), located to the
to operation of the tester.
front panel below and to the left of the
speed control handwheel (par. 18 above),
15. Vacuum Gage
has a metal protecting cage type cap and
The vacuum gage (1) (identified as
remains lit when the tester is in opera-
"INCHES VACUUM" on the dial face) is
tion.
located directly below the dwell meter
20. Motor Switch
a vacuum pump (an integral part of the
The motor switch (17), located to the
variable speed device) and registers the
left of the indicator light (par. 19 above),
amount of vacuum applied to the distrib-
is a three position toggle switch and is
utor diaphragm. The gage is calibrated
used to start the tester motor and control
in inches of mercury from 0 to 21. The
the direction in which it operates. Snapping
vacuum gage adjustment screw (22) is
the switch to the left operates the motor
located on the dial face and is used to ad-
f o r left-drive distributors, to the right
just the gage to zero before the tester is
o p e r a t e s the motor for right-drive dis-
started. To adjust the pointer to zero, in-
t r i b u t o r s and center position turns the
sert a screwdriver blade through the metal
drive motor off.
ring in the glass covering the dial and turn
t h e v a c u u m g a g e adjustment screw
c l o c k w i s e or counterclockwise, as re-
quired.
21. Speed Range Selector
The speed range selector (18), located
16. Vacuum Control
to the left of the stroboscope near the
bottom of the control panel, is a double
The vacuum control (13), located at the
lower right hand corner of the control
throw toggle switch and is used to select
the desired speed range of the distributor.
panel, is used to control the amount of
operational vacuum required by the dis-
Snapping the switch to its downward posi-
tributor being tested. Turning the control
tion operates the distributor from 0 to
counterclockwise to its fullest extent shuts
500 rpm. When the switch is thrown in its
off the vacuum. Adjust the vacuum gage
upward position, the speed of the shaft of
to the desired position by turning the con-
the distributor is operated from the 500
trol clockwise.
to 2000 rpm range.
8
