Motorola ASTRO 25 GTR 8000 User Manual

5.1.1
GTR 8000 Base Radio
Time and Frequency Inputs
Various external time and frequency inputs can be provided to the base radio for normal operation or
for Internal Frequency Reference Oscillator alignment. The following table provides a list of acceptable
input signal types and levels for each input port.
Table 46: Time and Frequency Inputs
Input Port Frequency Waveform Level
Impe-
dance
Note
Ext Freq Ref 5 MHz Sine 2.6–5.3 Vpp 100k
ohms
AC coupled
Ext Freq Ref 5 MHz Square
45–55% duty cy-
cle
100k
ohms
AC coupled
Ext Freq Ref 10 MHz Sine 2.6–5.3 Vpp 100k
ohms
AC coupled
Ext Freq Ref 10 MHz Square 45-55% duty cy-
cle
100k
ohms
AC coupled
Ext Freq Ref 20 MHz Sine 2.6–5.3 Vpp 100k
ohms
AC coupled
Ext Freq Ref 20 MHz Square 45–55% duty cy-
cle
100k
ohms
AC coupled
Ext Freq Ref 5 MHz/
1PPS*
Square 2.6–5.3 Vpp 100k
ohms
AC coupled;
25% modula-
tion 1pps ar-
rives on 75%
duty cycle
1PPS 1PPS Pulse 2.6–5.3 Vpp 100k
ohms
DC coupled
Front Panel
Ext Freq Ref
5 MHz Sine 2–5 Vpp; 10–18
dBm
50 ohms AC coupled
Front Panel
Ext Freq Ref
5 MHz Square 45–55% duty cy-
cle
50 ohms AC coupled
Front Panel
Ext Freq Ref
10 MHz Sine 2–5 Vpp; 10–18
dBm
50 ohms AC coupled
Front Panel
Ext Freq Ref
10 MHz Square 45–55% duty cy-
cle
50 ohms AC coupled
Front Panel
Ext Freq Ref
5 MHz/
1PPS*
Square 2.6–5.3 Vpp 50 ohms AC coupled;
25% modula-
tion 1pps ar-
rives on 75%
duty cycle
* 25% modulation, 1PPS arrives on 75% duty cycle.
NOTICE: The Front Panel EXT FREQ REF connection is the Frequency Calibrator (BNC
connector) on the transceiver module.
MN003286A01-E
Chapter
5: GTR 8000 Base Radio Optimization
157

Motorola ASTRO 25 GTR 8000 Specifications

General

Brand	Motorola
Model	ASTRO 25 GTR 8000
Category	Radio
Language	English