Instruction Manual

Instruction Manual Page 9 of 25
TRANSMITTER
No. Parameter Requirement Comments
1 Modulation Type DC/MA® 16QAM (2 level 8 phase) – Digital
Channel/Multicarrier Architecture
2 Output Power 4 Watts Pulsed Average
(Maximum)
3 Output Impedance
50 Ω
3 Harmonic Distortion -57dBc Two tone, third order products.
4 Microphone Impedance
3 kΩ
5 Microphone Input
750 Ω
Parallel of microphone input and
microphone impedance is 600 Ω
6 Frequency Stability Initial = 0.1 PPM
Temperature = 2.5 PPM
Aging = 1 PPM/yr.
Improved stability when synchronized to
the repeater. The repeater clock is stable
to ± 0.002 PPM.
7 Channel Frequency spread 18 MHz
8 Adjacent Channel Power Ratio 60 dBc
9 Occupied Bandwidth 20 kHz An 800 MHz, 25 kHz DC/MA® channel is
divided into four sub-channels with
channel offsets of ±2400 Hz and ±7200
Hz. Each of the individual sub-channels
is about 4 kHz.
10 Transmitter Carrier Attack Time < 0.5 msec < 2 symbols with each symbol being 0.25
msec
RECEIVER
No. Parameter Requirement Comments
1 Modulation Type DC/MA® 16QAM (2 level 8 phase)
2 Sensitivity
0.45 µV (-114 dBm)
Based on 6% BER.
3 Input impedance
50 Ω
VSWR < 2.5:1
4 Intermediate Frequency 1
st
IF 86.85 MHz
2
nd
IF 450 kHz
5 Frequency stability Initial = 0.1 PPM
Temperature = 2.5 PPM
Aging = 1 PPM/yr.
Improved stability when synchronized
to the repeater. The repeater clock is
stable to ± 0.002 PPM.
6 Channel frequency
spread
18 MHz
7 Spurious rejection >70 dB
8 Adjacent Channel
Selectivity
>70 dB Adjacent-channel FM-signal rejection
measured 25 kHz from the receiver
carrier.
9 Receiver IM Margin >70 dB Intermodulation of the receiver. Based
on cellular alternate channel definition
with F
1
at 50 kHz and F
2
at 100 kHz
from test channel.
10 Image rejection >70 dB
11 Rated Audio output
0.5 W RMS into 8 Ω (internal)
3.5 W RMS into 8 Ω (external)
At < 5% @ 1kHz THD