Transcript
Eclipse Series
RF Technology
[email protected]
October 2005
Exciter Data Interface Operation, Maintenance and Installation Manual
This Manual is produced by RF Technology Pty Ltd 10/8 Leighton Place, Hornsby NSW 2077 Australia Copyright © 2003 RF Technology Pty Ltd
CONTENTS
CONTENTS
Contents 1
Operating Instructions 1.1 Data Inputs 1.2 Tx Input 1.3 Centre Frequency Transmission 1.4 Timing Considerations 1.5 Transmission Delay 1.6 Data Bit Rates 1.7 Data Errors 1.8 Support Software
3 4 4 4 4 5 5 5 5
2
I/O Connections 2.1 Polarity Selection 2.2 Delay and Test Frequency Selection
6 6 6
3
Circuit Description
6
4
Installation
8
5
Alignment Procedure
9
6
DMTX with OCXO and DMTX standard photos
10
7
Component layout drawing
11
8
DMTX Schematic with OCXO
12
9
DMTX Schematic (standard)
13
10
JP23 and R159 positions
14
11
Modifications to VHF TX board version 3 or earlier
15
12
Modifications to UHF TX board version 3 or earlier
16
Page 2 of 16
RF Technology Exciter Data Interface with OCXO option
OPERATING INSTRUCTIONS
WARNING Changes and modifications not expressly approved by RF Technology could void your authority to operate this equipment. Specifications may vary from those given in this document in accordance with requirements of local authorities. RF Technology equipment is subject to continual improvement and RF Technology reserves the right to change performance and specifications without further notice.
1
Operating Instructions
Identifying DMTX cards Part number 30/9114/003 or later have onboard facility to accommodate the OCXO high stability oscillator option. Part number 30/9114/001 is the standard DMTX card which relies on the main board TCXO for the reference signal. Identifying Transmitter main boards UHF transmitter main board 30/9103/0004 or later and VHF transmitter main board 30/9116/0004 or later have installed jumper link JP23 and audio signal routing for easy plug-in operation of the DMTX card. Note: Transmitter main board versions earlier than the above part numbers require modification as detailed in the rear sections of this manual for satisfactory operation with the DMTX card. DMTX Part no. 30/9114/003 or later with OCXO high stability oscillator The high stability oscillator (OCXO) option is available with the DMTX part no. 30/9114/003 or later. This option is for VHF transmitters only. In operation, the high stability oscillator replaces the 12.8MHz crystal in VHF transmitters as the reference oscillator. The OCXO has a stability specification of +/- 0.05 ppm at temperature range –30 deg C to 60 deg C. i.e. +/-7.5Hz accuracy at 150MHz. Digital and audio modulation inputs are provided without modification to VHF transmitters with main board version 30/9116/0004 or later with JP23. The digital modulation input is through the data interface and supplied DB9 connector. The audio modulation input is via the standard DB25 connector.
Page 3 of 16
RF Technology Exciter Data Interface with OCXO option
1.1 Data Inputs
1 OPERATING INSTRUCTIONS
DMTX Part no. 30/9114/001 (standard card) This card utilizes the transmitter TCXO as the reference signal input. Digital and audio modulation inputs are provided without modification to VHF transmitter main board 30/9116/0004 or later with JP23 and UHF transmitter main board 30/9103/0004 or later with JP23. The digital modulation input is through the data interface module and supplied DB9 connector. The audio modulation input is via the standard DB25 connector.
1.1
Data Inputs
Jumper JP1 can be set to accept either TTL or RS-422 input levels. The data polarity is selected by jumper JP3. The normal polarity is set so that a logic 1 input produces a negative frequency shift.
1.2
Tx Input
The data Tx input is used to turn the transmitter ON. Both TTL and RS-422 level inputs are provided and are selected by JP2. The polarity of the Tx input is set by jumper JP4. The normal polarity is set so thet a logic 0 turns the transmitter ON.
1.3
Centre frequency Transmission
The interface module can be configured by setting JP5 to transmit on the channel centre frequency during the delay period or when the test button is pressed. This is useful for transmitter tests and frequency calibration. In the normal configuration, the frequency output always follows the data input.
1.4
Timing Considerations
The Tx input must be true at least 25mSec. before the start of the first data bit. This is to allow time for the transmitter to turn ON and for the receivers carrier detect circuit to operate. The Tx input may return to false coincident with the end of the last data bit, but it is more usual to keep the transmitter ON for a short period after the last data bit is sent. Some operators like to keep the transmitter ON between successive short data bursts to avoid the 25mSec. delay. This can easily be accomplished by programming the transmitter delay. The transmitter delay can be sent in one second increments between 0 and 15 seconds.
Page 4 of 16
RF Technology Exciter Data Interface with OCXO option
1.5 Transmission Delay
1.5
1 OPERATING INSTRUCTIONS
Transmission Delay
The total transmission delay from the transmitter data input to the receiver data output is approximately (500 + 3.33* Km.) uSec. Where Km is the radio path distance in kilometres. System designers should keep in mind since at the higher data speed this is equivalent to several bits.
1.6
Data Bit Rates
The direct FSK/NRZ transmission system employed can accept speeds up to 4800 Bps. It will provide low bit error rates on a clear channel at that speed.
1.7
Data Errors
Radio channels are subject to various types of interference. In most cities interference free channels are rare if not impossible to finds. As with any data transmission system which is prone to interference, error detection and correction schemes should always be used where the integrity of the transmitted data is of concern.
1.8
Support Software
The transmitter delay can be set using the TecHelp Software or Service Monitor. TecHelp and Service Monitor can be obtained through your dealer or distributor.
Page 5 of 16
RF Technology Exciter Data Interface with OCXO option
2
I/O CONNECTIONS
2.0
I/O Connections
9 Pin Connector (DB9) Functions/Signal TTL Tx Input +Tx Input -Tx Input Ground Ground Ground TTL Data Input +Data Input -Data Input
2.1
Specification 0<0.8V, 1>2.2V RS-422 RS-422
Data JP3_ 1-2 3 1 2-3
Tx JP4_ 1 2-3 1-2 3
Delay and test Frequency Selection Jumper Positions(-) Frequency Follows Data Frequency Shifts to Centre During Delay/Test
3.0
0<0.8V, 1>2.2V RS-422 RS-422
Polarity Selection
Jumper Positions (-) Normal Polarity Reverse Polarity
2.2
Pin 1 2 3 4 5 6 7 8 9
JP4_ 1 2-3 1-2 3
Circuit Description
The following descriptions should be read as an aid to understanding the schematic diagram at the rear of this manual. Data and Tx Inputs: The TTL logic level inputs from the 9 pin connector are buffered by CMOS invertors U2b,c,d,e to obtain the complementary logic levels to control analog switches U3a-d. Jumpers JP1 and JP2 can be set to select the RS-422 inputs instead of TTL. Differential line receivers U1a and U1b convert the RS-422 inputs to TTL levels.
Page 6 of 16
RF Technology Exciter Data Interface with OCXO option
3 CIRCUIT DESCRIPTION Reference Voltage Source: D3 is a band-gap reference diode which supplies a very stable 2.5 volts. The U5a is used to double the voltage to 5 volts. VR1 is used to set the low frequency voltage reference. It can be adjusted between 2.5 and 5 volts. VR2 is used to set the high frequency voltage reference and can be set between 0 and 2.5 volts. Analog Data Signal: The buffered data input signal is connected to analog gates U3b and U3d. These are used to switch between the two pre-set reference voltages so that the input to voltage follower U5b follows the data input. Data Filter: Two four pole flat delay low pass filters are used to remove the high frequency components from the data waveform. The attenuation of the filter is sufficient to ensure that the transmitters modulation products do not encroach on the adjacent radio channels. The filter uses operational amplifiers U4a-d as voltage controlled voltage sources. The filter output is connected to the transmitters frequency control input to produce FSK modulation.
Page 7 of 16
RF Technology Exciter Data Interface with OCXO option
4 INSTALLATION
4.0
Installation
1.
Remove the transmitters two side covers. Temporarily disconnect the cables to the power amplifier. Locate the “D” connector cut-out on the rear panel and remove any labels which may be covering the holes. From the top side of the exciter board install the 9 pin “D” connector using two 4-40 screws. Mount the four M3x12mm spacers on the PCB in the holes provided. The spacers mount from the component side of the board with the screw thread end of the spacer through the hole. A shake-proof washer is used on the component side of the board and a flat washer and nut ate used on the bottom side. For DMTX with OCXO option fitted: Remove the following components from the transmitter main board if the OCXO option is installed on DMTX card a. Remove R152 b. Remove Q29 c. Remove R143 For transmitters with JP23, main board version 0004 or later: Move JP23 links from Pins 1-2, 5-6 to 2-3, 4-5 Add R159, 270 ohm ¼ watt resistor for VHF transmitter or Add R159, 1 ohm ¼ watt resistor for UHF transmitter For VHF transmitters with main board version 0003 or earlier Refer to the modification drawings at the rear of this manual Remove C112 and C117, connect the negative pads of C112 and C117 on the bottom of the board. Connect JP15 pin 5 to the positive terminal of C117 position (U7 pin 7) Bridge R140 with a 270 ohm ¼ watt resistor on the bottom of the board. Short across R139 on the bottom of the board. Using 7 x .2mm PVC insulated hook-up wire to connect JP15 pin 6 to the anode of D10. For UHF transmitters with main board version 0003 or earlier Refer to the modification drawings at the rear of this manual Remove C117, connect JP15 pin 5 to the positive terminal of C117 position (U7 pin 7) Short across C112, R139 and R140 on the bottom of the board. Using 7 x .2mm PVC insulated hook-up wire to connect JP15 pin 6 to the anode of D10. Plug the 10 pin socket connector on the end of the flat input cable into P1 on the interface module. Plug the interface module into JP15 on the exciter board and secure with four M3x6mm screws. Re-connect the power amplifier cables and set the frequency shift according to the alignment procedure. Set the jumper options as required and replace the covers.
2. 3. 4.
5.
6.
7.
8.
9.
10. 11.
Page 8 of 16
RF Technology Exciter Data Interface with OCXO option
5 ALIGNMENT PROCEDURE
5.0
Alignment Procedure
Test Equipment Required Dummy Load Frequency Counter Signal Generator Comms test Set OR Receiver (Discrim output) CRO Jumper Configuration -
50ohms, 50 watts 500MHz min., 0.1ppm accuracy 1KHz square wave capable (TTL) RF Demodulation RF Demodulation View signal waveform Normal Polarity, TTL default
VHF transmitter with DMTX Part no. 30/9114/003 or later Step
Input
Measure
1
Press Front panel TX PB switch
Frequency
2
Tx Input = 0 Data Input = 1
Frequency
3
Tx Input = 0 Data Input = 0
Frequency
4
Tx Input = 0 Data Input = 600Hz TTL square wave
Use CRO to view demod. waveform
Adjust for 25KHz Model Check centre frequency is correct VR1 to obtain the centre frequency -4.5KHz VR2 to obtain the centre frequency +4.5KHz MOD BAL for best square wave shape ie flat tops and bottoms
(OCXO option)
Adjust for 12.5KHz Model Check centre frequency is correct VR1 to obtain the centre frequency -2.5KHz
Adjust for 12.5KHz Model with OCXO Check centre frequency is correct VR1 to obtain the centre frequency -2.0KHz
VR2 to obtain the centre frequency +2.5KHz
VR2 to obtain the centre frequency +2.0KHz
MOD BAL for best square wave shape ie flat tops and bottoms
MOD BAL for best square wave shape ie flat tops and bottoms
VHF or UHF transmitter with DMTX Part no. 30/9114/001 Step
Input
Measure
Adjust 25KHz Model
Adjust 12.5KHz Model
1
Press Front panel TX PB switch Tx Input = 0 Data Input = 1
Frequency
Check centre frequency is correct VR1 to obtain the centre frequency -4.5KHz
Check centre frequency is correct VR1 to obtain the centre frequency -2.5KHz
3
Tx Input = 0 Data Input = 0
Frequency
VR2 to obtain the centre frequency +4.5KHz
VR2 to obtain the centre frequency +2.5KHz
4
Tx Input = 0 Data Input = 600Hz TTL square wave
Use CRO to view demod. waveform
MOD BAL for best square wave shape ie flat tops and bottoms
MOD BAL for best square wave shape ie flat tops and bottoms
2
Page 9 of 16
Frequency
RF Technology Exciter Data Interface with OCXO option
6.0
DMTX with OCXO and DMTX standard
DMTX Part no. 30/9114/003 (OCXO option)
DMTX Part no. 30/9114/001 (standard card)
Page 10 of 16
RF Technology Exciter Data Interface with OCXO option
A
B
C
D
E
+9.4V
D3 LM336Z2.5
R21 4K7
2K2
R20
6
5
VR* 10K
TLC272
U5B
+5V
100N
R24 100
R* 470K
7
C16
JP6
C14 100N
4
3
2
1
U5A VAB TLC272
C1 10N
R9 11K0
PA3
PA4
PA5
VDD
1
PA2
PA1
PA0
1 2 3 4 5 6 7 8 9 10
5
6
7
8
R19 2K21
R18 2K21
2
3
V0
C20 22N
R27 47K
VC
C3 2N2
R11 23K7
5
6
7
8
C17 100N
C4 1N0
R12 15K8
C9
R1 4K7
5
2
6
5 7
U7B TLC272
OCXO12.8 MHz
XO1
OUT
VC
7
100K
R7
4
3
2
U4B TLC274
+5VIN
6
5
R5 4K7
+5V
B
A
+5V
100K
R2
1
U1 100N DS9637
1N4148
D2
R28 47k
R6 100
R4 100
1N4148
D1
Black noise generator
VR2 10K
10K
VR1 V1
1
TTL_TX +TX -TX REF
TTL_DAT +DAT -DAT
U4A TLC274 +9.4V
P1
C13 100N
VSS
U6 68HC908QT
2
3
+9.4V
C2 4N7
R10 2K21
8
4
4
11
JP1
JP2
1 2 3
1N
C18
R29 47K
C5 10N
R13 11K0
1 2 3
R31 1K
R30 47K C21 1N2
R26 47K
C6 4N7
6
C19
9
C22 1N2
2
3
U7A TLC272
R36 4K7
U4C TLC274 10
3 2 1
JP4
10
1N Q2 MMBT2369
4049
U2C
4049
U2D
R3 2K21
7
9
3 2 1
JP3
4049
U2B
4049
+5V
R33 330R
4
12
1
JP5
14
3
5
B
V0
13
100N
C15
10R
R16
+5V
R35 100
10K
A
11
U3E 4066
Date: File:
A3
Size
Title
VSS
VDD
C
B
U3B 4066
U3A 4066
10
VC
U3C 4066
100K
100K
R22
14
U4D TLC274
DPTT
+5V
C23 1U
9
C
DPTT
R34 470K
13
12
2
15
A
U3D 4066
R23 R25
8
U2F 4049
4049
U2A
+5V
OPTIONAL
C25 1N
C8 1N0
R15 15K8
OPTIONAL
C24 1N
C7 2N2
R14 23K7
Q3 MMBT2369
R32 10R
+5V
8
5
11
U2E
V1 C 6
F
1 2
1 + G 3
G 4
1 2 3
3 B A 4
+5V
8 4
1 A B 2
C 12 14 7
VT
Q1 3904
PTTO +5V
VSS
9114 V3
C10 100N
1 2 3 4 5 6 7 8 9 10
J1
Revision 11-Oct-2005 Sheet 1of 1 G Lou D:\Protel Files\Work Files\DM_EXREF.ddbDrawn By:
Number
DMTX+OCXO
U2G 4049
R17 10R
C11 VDD 100N
C12 100N
12.8M MOD PTTO EXT-REF-LOCK +5VIN 9.2V_TX +9.4V
10K
R8
1 8
A
B
C
D
E
F
Move jumper links JP23 to inside position
For pcb with JP23
VHF TX- R159 is 270 ohm
UHF TX- R159 is 1 ohm
For pcb without JP23
For pcb without JP23
