190-01115-01
G3X/G3X Touch Installation Manual - GTR 20 Installation
Rev. AC
Page 21-3
21.3 General Specifications
See
for power/current specifications, and
for dimension/weight specifications.
21.3.1 COM Specifications
The GTR 20 transmitter meets the requirements of RTCA DO-186B section 2.3 for a class 4 transmitter.
The GTR 20 receiver meets the requirements of RTCA DO-186B section 2.2 for a class C receiver.
Table 21-4 Transmitter Specifications
Characteristic
Specification
Microphone Input
Two inputs, standard carbon or dynamic mic with integrated preamp.
The GTR 20 provides a 150
Ω
AC input impedance and supplies the
microphone with an 11 V bias through 470
Ω
+/- 5%.
Modulation Capability
85% with 150 to 1500 mVRMS microphone input at 1000 Hz. Range
can be extended from 20 mVrms to 2500 mVrms with mic gain
adjustment.
Modulation
AM Double sided Emission Designator: 6K00A3E (118 - 136.975 MHz)
Frequency Range
118.000 to 136.975 MHz, 25 kHz channel spacing
Frequency Tolerance
+/-5 ppm from -20°C to +55°C
Output Power
10 Watts carrier minimum
Duty Cycle
20%
Carrier Noise Level
At least 35 dB (SNR)
Stuck Mic Time-Out
35 seconds time-out, reverts to receive
Demodulated Audio Distortion
Less than 25% distortion when the transmitter is at 85% modulation at
350 to 2500 Hz
Table 21-5 Receiver Specifications
Characteristic
Specification
Frequency Range
118.000 to 136.975 MHz, 25 kHz channel spacing
Headset Audio Output
60 mW minimum into a 150
Ω
load
Audio Response
Less than 6 dB of variation between 350 and 2500 Hz
Audio Distortion
Less than 25% at rated output power
Sensitivity
SINAD greater than 6 dB when the RF level is -107 dBm with 30% modulation
Squelch
Automatic squelch with manual override
