Garmin APOLLO GX SERIES Service Manual - page 54
Garmin AT
Rev --
7-16
GX Service Manual
© 2004 Garmin AT
Performance Specifications
Transmitter Performance Specifications
Parameter Specification
Class D
Output Power
8 W minimum carrier at > 12 VDC in 6 W minimum carrier at 10 VDC
in. Transmit is locked out below 9 VDC input (no modulation).
Frequency range
118.000 MHz to 136.975 MHz, 760 channels
Frequency tolerance
±15 PPM from -20
° C to +70° C
Microphone input
Two inputs: standard carbon or dynamic MIC with integrated pre-amp
providing minimum of 70 mV RMS into 1000 Ω load.
Modulation capability
1. 85% with 1000 Hz at 100 mV to 1000 mV RMS microphone input
Audio frequency distortion <10% at 85% modulation at 350 Hz to 2500 Hz
Audio frequency response
<4 dB variation with 350 Hz to 2500 Hz, 85% modulation
Carrier noise
>35 dB down
Sidetone output
Up to 280 mW into 100 Ω load, 120 mW into 500 Ω load
Duty cycle
100%
Stuck mic time-out
35 seconds, reverts to receive
Transmit key
Input pull low to enable transmitter
Receiver Performance Specifications
Parameter Specification
Frequency range
118.000 MHz to 136.975 MHz, 760 channels
Sensitivity
1 µV (2 µV hard) for 6 dB SINAD with 30% modulation at 1000 Hz
Selectivity
<6 dB variation at ±7 kHz, > 60 dB at ± 22 kHz
Speaker audio output level 12 watts into 4 Ω, 8 watts into 8 Ω
Headphone audio output
level
2. 280 mW into 100 Ω,120 mW into 500 Ω
Distortion
<5% at rated output at 1000 Hz
AGC characteristics
< dB variation in audio output from 5 µV to 100 mV input 15% to 90%
modulation
Squelch control
Automatic squelch with manual override