GPR3000
unit manual
The
GPR3000 unit is designed for use with block
upconverter modules operating in the C,
Ku or DBS satellite frequency bands.
The
Unit contains single or separate dual circuitry,
each providing an L band route for the transmit
data signals, 10MHZ signals from a high
stability oven controlled crystal oscillator
used to lock the block up converter (BUC)
to, and a +24V DC supply to power the BUC.
All of these signals are inserted onto the
‘composite’ output for connection to the
cross-site cables. |
Warning – the composite output connector from the GPR3000
has +24V DC supply between pin and body of the connector.
Care must be taken if test equipment is connected to
this port.
System Block
diagram:
GPR3000
Power Reference Unit:
The
circuitry is housed within a 2U 19 inch rack unit having
visual indications on the front panel for the internal
circuitry and clean contact alarms via a 25 pin D type
connector on the rear.
Internal
circuitry monitors the following status for each circuit:
Block up converter
current. If the Block Upconverter looses lock with the
10MHZ crystal it will Mute its output. If this happens
the current drawn from the GPR3000 will reduce from
approximately 1.2A to 300mA and generate a ‘BUC’ alarm
within the unit.
The crystals
within the unit also provide alarms when the oven temperature
is not within specification (this will happen for a
while after switch on) and if the RF power on the 10MHz
signal is low.
The Power supplies
within the unit are also monitored and in the event
of a failure will produce a visual and clean contact
alarm.
Visual Indications:
LED on front panel
|
(if
fitted) |
BUC 1 |
BUC 2 |
Oven
1 |
Oven
2 |
10 MHz
Ref RF 1 |
10 MHz
Ref RF 2 |
PSU 1 |
PSU
2 |
The 10MHZ crystal
frequency has electrical and mechanical adjustment.
In the event of the crystal aging it may be necessary
to adjust the oscillator frequency. A potentiometer
mounted on the rear panel of the unit will electrically
adjust the frequency of oscillation, however the accuracy
of the crystal will be as good or better than the measurement
equipment and it is therefore recommended to monitor
the ku band signals when adjusting the potentiometer.
When delivered
the adjustment is set to its central position, it is
not expected that physical adjustment will be needed
but in this eventuality, access can be obtained to the
crystal body by removing the top cover of the unit.
It is recommended
that the transmit frequency is checked and adjusted
every 6 months. In the event that, because of the nature
of the service, it is not possible to measure the transmit
frequency Eutelsat
and Intelsat will help in ensuring that the transmit
frequency is correct by monitoring the signals on the
satellite and advising whether adjustment is necessary.
Call the CSC in Eutelsat on +33 1 45570666 for support.
TPR3000 Alarm Connections
Pin
number |
Condition |
Alarm |
|
1 |
N/C |
|
|
2 |
N/O |
PSU
1 |
|
3 |
Com |
|
|
4 |
N/C |
|
|
5 |
N/O |
PSU
2 |
|
6 |
Com |
|
|
7 |
N/C |
|
|
8 |
N/O |
BUC
1 |
|
9 |
Com |
|
|
10 |
Com |
|
|
11 |
N/O |
BUC
2 |
(if
fitted) |
12 |
N/C |
|
|
13 |
N/C |
|
|
14 |
N/O |
Xtal RF Power 1 |
|
15 |
Com |
|
|
16 |
N/C |
|
|
17 |
N/O |
Xtal Oven Temp 1 |
|
18 |
Com |
|
|
19 |
N/C |
|
|
20 |
N/O |
Xtal
RF Power 2 |
(if
fitted) |
21 |
Com |
|
|
22 |
N/C |
|
|
23 |
N/O |
Xtal Oven Temp 2 |
(if
fitted) |
24 |
Com |
|
|
25 |
N/Used |
|
|
Specification:
Physical:
Size:
19 inch rack unit,
2U, 350mm deep.
Weight:
2.5 Kg.
Power:
Mains:
220-240V AC
Consumption:
25W (typical)
Indications:
Front panel:
Status LEDs.
Contacts:
Form C contacts for
alarm conditions.
Reference (10MHz):
Frequency stability /day:
1 x 10-9
Phase
Noise:
dBc/Hz
Offset 10Hz.
-120
100Hz.
-130
1kHz.
-150
10kHz.
-155
100kHz.
-155
10MHz Power
+3 to +7dBm
L Band:
Frequency
950 -1450MHz
Through
Loss
3-5dB.
DC supply power:
+24 V @ 2A (BUC supply)
Connections:
Mains:
IEC.
L band i/p
1 & 2:
N type ‘F’
L
band o/p 1 & 2:
N type ‘F’
Alarms:
25W D.
|
