Spektrum DX3S User Manual page 20

To select the telemetry sensor settings, rotate the Rolling
Selector and place a box around Tele- SPEED then press
the Rolling Selector. The surrounding box will flash.
Rotate the Rolling Selector to select the desired sensor
setting for adjustment then press the Rolling Selector.
Use the Rolling Selector to select the sensor parameters
to adjust.
Press the Rolling Selector and a surrounding box will
flash.
Use the Rolling Selector to adjust the value and press the
Rolling Selector to select.
To return to the main screen press and hold the Rolling
Selector for more than three seconds.
Tele-SPEED
Zoom - The Zoom setting sets the maximum range or
boundary of the Speed unit.
Unit - Select RPM, MPH, KM/H display units
Roll Out - The Roll Out function is only visible when the
unit is set to mph or km/h and is the internal calculator
that allows rpm data to be converted to mph or km/h.
When the Roll Out value is set to 1.0, the default setting,
the value displayed on the main screen and stored in
maximum speed, is true rpm of the shaft gear or flywheel
that the rpm sensor is hooked up to. In order to program
the unit to display speed in mph, a conversion factor is
needed. Following are two methods of determining the
conversion factor.
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Method A
• Mark the clutch bell that the sensor is reading from
with a small reference mark. A marker works well.
• Set the car next to a ruler and at 0" then roll the car
forward by hand, counting each revolution of the
reference mark. At exactly 10 revolutions stop the
car.
• Measure the exact distance that the car traveled in
ten revolutions and divide this distance by 10 (e.g.
12.0" divided by 10 = 1.20").
• Adjust the Roll Out value until 1.20 appears on the
screen. Now all the rpm related functions will be
displayed in mph or km/h.
Method B
For this method you either need to know the internal gear
ratio (normally provided in the vehicle's manual) or be
able to calculate the ratio via the number of teeth on the
gears. It is also necessary to calculate the circumference
(distance around) of the tire. Once the internal ratio
is known, and the circumference in inches has been
determined, simply divide the circumference by the
internal ratio and use this value as the conversion.
To calculate circumference—multiply 3.14 x the tire's
diameter in inches.
To calculate internal gear ratio—divide the larger gear
by the small gear. With multiple gear transmissions, it is
necessary to multiply each of the larger to smaller gear
reduction ratios to arrive at the final ratio.
Note: The Telemetry screen displays the
maximum recorded speed from the point
that the receiver was turned on. To reset the
maximum recorded speed, it is necessary to
turn off the receiver, then back on.
SPEKTRUM DX3S USER GUIDE