Introduction
The ALT-1 is a 2 1/4” instrument that contains a precision encoding altimeter and a wide range vertical speed indicator.
The altimeter conforms to ANSI standard atmosphere rules from –700 ft up to a maximum of 30 000 ft. The altimeter
includes an encoding serial output that when used in combination with MGL Avionics CNV-AT, provides a parallel Gillham
code interface for transponders. The altimeter can display altitude in feet or meters, local pressure can be set in millibars
or inches of mercury
The onboard VSI indicator is altitude compensated and can be displayed in either feet/minute (ft/min) or meters/second
(m/s). It also offers a digital readout with a wide range from +/-20 ft/min to as high as +/-10 000 ft/min, it also offers a
logarithmic analog display with a +/-2000 ft range. The VSI can be calibrated by the user once the instrument has been
installed in the aircraft.
In addition the ALT-1 provides an OAT sender which is used in determining the density altitude of the aircraft. The ALT-1
can also be used to measure relative altitude and it has a facility for the pilot to enter a reference altitude and deviation
band that has to be kept.
1 Features
• Precision altimeter from –700 ft up to a maximum of 30 000 ft (-213m to 9144m)
• Provides altitude encoder data on airtalk (serial) output, which can be converted by a MGL Avionics CNV-
AT converter to a parallel Gillham code interface for transponders
• The altimeter can display altitude in feet or meters, local pressure can be set in millibars or inches of
mercury
• Contains a wide range VSI indicator from +/-20 ft/min to as high as +/-10 000 ft/min
• VSI units can be in feet/minute (ft/min) or in meters/second (m/s)
• Records the maximum and minimum OAT (outside air temperature) and maximum altitude reached in
permanent memory
• Records maximum and minimum OAT in temporary memory since instrument power up
• Standard 2 1/4” aircraft enclosure (can be front or rear mounted)
• Rotary control plus 2 independent buttons for easy menu navigation and user input
• Alarm output as well as a red LED illuminates when the alarm has been activated
• Large backlit graphic LCD with adjustable contrast
• Wide input supply voltage range of 8 to 30V DC with built in voltage reversal and over voltage protection
for harsh electrical environments
• Light weight design
• Field upgradeable firmware
• 1 year limited warranty
ALT-1
Precision Encoding Altimeter and
Vertical speed indicator (VSI)
Operating Manual – English 1.08
