Rhotheta RT-1000 User manual

User Manual
RT-1000
Antenna Control

RT-1000 Antenna Control
RHOTHETA Page 2 of 10 User Manual
Edited by:
RHOTHETA Elektronik GmbH
Kemmelpark
Dr.-Ingeborg-Haeckel-Str. 2
82418 Murnau
Germany
Tel.: [phone] - 0
Fax: [phone] - 15
Internet: www.rhotheta.de
E-Mail: [email protected]
Copyright © RHOTHETA Elektronik GmbH
All rights reserved
-Issue: 2016/01/28 [Rev 1.00]
-Document-ID: 12-9-3-1-00023-3-3-60
Note
The manufacturer reserves the right to make modifications at any time and without previous
information of the here described product.

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Content
1 Description.......................................................................................................................4
2 Front View ........................................................................................................................4
3 Rear View..........................................................................................................................5
4 R/L OFF Button................................................................................................................6
5 Interfaces..........................................................................................................................6
5.1 Antenna Control Jack .............................................................................................................................6
5.2 Backplane Interfaces..............................................................................................................................7
5.3 Signal Sequences...................................................................................................................................8
5.3.1 Antenna Control Signal..............................................................................................................8
5.3.2 6,144 MHz Reference Signal.....................................................................................................8
5.3.3 R/L Pulse ...................................................................................................................................9
6 Notes...............................................................................................................................10

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1 Description
The antenna control unit supplies the special control signals required for cyclic electrical
rotation of the four dipoles. Actually the four dipoles are switched in the right order in order to
simulate one antenna which is running on circle orbit. Hence, the Doppler modulation is
generated.
The RT-1000 Direction Finder system operates on the Doppler principle. To compensate the
bearing deviation due to the group delays of the filter components, the antenna rotation is
performed 32 times clockwise and 32 times counter clockwise. This is the so called left- and
right-rotation. The rotation frequency is 3 kHz.
Further the antenna control provides reference signals, which are used by DF Channels in
order to determine the correct bearing. One of these signals is a 6.144 MHz signal, which is
used as reference to calculate bearing, which is exactly synchronous to the 3 kHz rotation.
Another one is the R/L-Pulse (Right Left Pulse) which is used by DF Channels in order to
detect the appropriate rotation direction.
Additionally, the antenna control module has a SUBD9 interface with antenna control signals,
which can be used to drive the antenna model (see User Manual Antenna Model) and with
this allow the bearing test of the system without the real antenna.
The R/L Off button on the front panel is made for testing issues. It stops the switching
between clockwise and counter clockwise rotation. Thus, the oscillogram of the antenna
control signals can easily be made and assessed without triggering on the R/L-Pulse.
2 Front View
R/L OFF (S2): Switch OFF the change of
clockwise and counter clockwise rotation.
Antenna Control (X2): Output of the
antenna control signals. Connection to
the antenna model

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3 Rear View

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4 R/L Off Button
The R/L Off button interrupts the right/left antenna rotation. If this button is pressed and the
received signal is present, the value of 000° or 180°+ north adjustment (set in the system)
appears on the QDM display of the controller.
5 Interfaces
5.1 Antenna Control Jack
The antenna control D-Sub 9 jack (X2) is used to connect the RTM 1500 Antenna Model. The
same signals are transmitted as at the antenna control connection (X3). Additionally, the R/L
signal is available.
Backplane Interfaces
X2
Pin
Signal
Function
3
2
1
4
5
7
8
9
6
1 OST Antenna Control Signal, East
2 WEST Antenna Control Signal, West
3 GND Ground
4 GND Groung
5 +15 V DC Supply +15 V
6 SUED Antenna Control Signal, South
7 NORD Antenna Control Signal, North
8 R/L Right/Left rotation change-over signal
9 +15V DC Supply +15 V

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5.2 Backplane Interfaces
Backplane Interfaces
Connector
Pin
Signal
Function
X1 -- -- Internal connection
X2 1 -15 V DC Supply Input -15 V
DC
2 +15 V DC Supply Input +15 V
DC
3 +5 V DC Supply Input +5 V
DC
4 GND DC Supply Input Ground
X3 1 WEST Antenna Control Signal, West
2 EAST Antenna Control Signal, East
3 SOUTH Antenna Control Signal, South
4 NORTH Antenna Control Signal, North
5 +15 V Antenna Control Signal, +15 V
DC
6 GND Antenna Control Signal, Ground
X4 -- R/L-PULS-1 Reference Signal R/L Pulse
X5 -- R/L-PULS-2 Reference Signal R/L Pulse
X6 -- R/L-PULS-3 Reference Signal R/L Pulse
X7 -- R/L-PULS-4 Reference Signal R/L Pulse
X8 -- 6144KHZ-1 Reference Signal 6,144 MHz
X9 -- 6144KHZ-2 Reference Signal 6,144 MHz
X10 -- 6144KHZ-3 Reference Signal 6,144 MHz
X11 -- 6144KHZ-4 Reference Signal 6,144 MHz
X12 1 ROT-OFF-1 ON/OFF Antenna Control Signals, Channel 1
2 GND ON/OFF Antenna Control Signals, Channel 1 Ground
3 ROT-OFF-2 ON/OFF Antenna Control Signals, Channel 2
4 GND ON/OFF Antenna Control Signals, Channel 2 Ground
X13 1 ROT-OFF-3 ON/OFF Antenna Control Signals, Channel 3
2 GND ON/OFF Antenna Control Signals, Channel 3 Ground
3 ROT-OFF-4 ON/OFF Antenna Control Signals, Channel 4
4 GND ON/OFF Antenna Control Signals, Channel 4 Ground
X14 1 ROT-OFF-5 ON/OFF Antenna Control Signals, Channel 5
2 GND ON/OFF Antenna Control Signals, Channel 5 Ground
3 ROT-OFF-6 ON/OFF Antenna Control Signals, Channel 6
4 GND ON/OFF Antenna Control Signals, Channel 6 Ground
X15 1 ROT-OFF-7 ON/OFF Antenna Control Signals, Channel 7
2 GND ON/OFF Antenna Control Signals, Channel 7 Ground
3 ROT-OFF-8 ON/OFF Antenna Control Signals, Channel 8
4 GND ON/OFF Antenna Control Signals, Channel 8 Ground

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5.3 Signal Sequences
5.3.1 Antenna Control Signal
Set the trigger top channel 1
Channel 1 – West Channel 2 - East Channel 3 – South Channel 4 - North
Limits:
U
high
≥+ 8,5 V
5.3.2 6,144 MHz Reference Signal
Limits:
U
high
≥+ 0,5 V
U
low
≤- 0,5 V
f = 6,144 MHz ± 3 kHz

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5.3.3 R/L Pulse
Limits:
t
high
= 5,1 µs ± 0,2 µs
t
low
= 21,3 ms ±0,5 ms
U
high
≥+ 1,0 V
U
low
≤+ 0,2 V

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6 Notes