ALT-1 Operating Manual
Page 9
On the back of the ALT-1 you will find the calibration number that has been determined to ensure
the most accurate reading of your altimeter. This is the value that should be entered here. Should
you have access to an accurate reference you may use this function to calibrate your altimeter.
Before you do this, ensure that you have your local pressure set to coincide with a calibrated and
certified reference. Your altimeter has been calibrated by the factory to an accuracy of +/- one mB or
approxi/- 30 ft (10m).
The ALT-1 is calibrated in degrees Celsius. The ALT-1 is calibrated at the factory using a precision
laboratory thermometer. If recalibration is required then adjust the value using the up/down keys or
the rotary control until the temperature matches the reference ambient temperature.
5 Altitude Encoder
To use the ALT-1 as an encoding altimeter an Airtalk to parallel Gillham code output encoder such as the MGL Avionics
CNV-AT must be used. This converter takes the Airtalk serial string that is outputted by the ALT-1 and converts it to a
parallel Gillham code suitable for aircraft transponders. Please see the CNV-AT operating manual for more information.
6 Loading factory default settings
Pressing and holding the F1 and F2 simultaneously on power up will cause the ALT-1 to load preprogrammed factory
default settings. The following screen will be displayed:
7 Operating the alarms
If the alarm is activated, the corresponding item on the display will flash. At the same time the externally available alarm
switch will close. The switch will remain closed until any button is pressed to acknowledge the alarm or until the
condition(s) that activated the alarm no longer exist. The alarm output can be used to switch an external alarm indicator.
The external alarm switch is an open collector transistor switch to ground with a maximum rating of 0.5A DC. It is possible
to wire the alarm contacts of several Stratomaster instruments in parallel should this be desired. To avoid false activation
of the alarms, the alarm function is only active 10 seconds after the instrument has powered up.
8 Cleaning
The unit should not be cleaned with any abrasive substances. The screen is very sensitive to certain cleaning materials
and should only be cleaned using a clean, damp cloth.
Warning:
The ALT-1 is not waterproof, serious damage could occur if the unit is exposed to
water and/or spray jets.
