3820 RWT & RWR.ib.Rev0 RWT_3820 RWR_ib_Rev0 RWR Ib Rev0

User Manual: 3820-RWT_3820-RWR_ib_Rev0

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3820-rwt & 3820-rwr.ib.rev0.doc Page 1 of 11 28/02/2006

IRT Eurocard

Types RWT-3820 / RWR-3820

L Band RF Fibre Optic Link

Designed and manufactured in Australia

IRT can be found on the Internet at:

http://www.irtelectronics.com

I R T Electronics Pty Ltd A.B.N. 35 000 832 575

26 Hotham Parade, ARTARMON N.S.W. 2064 AUSTRALIA

National: Phone: (02) 9439 3744 Fax: (02) 9439 7439

International: +61 2 9439 3744 +61 2 9439 7439

Email: sales@irtelectronics.com

Web: www.irtelectronics.com

DANGER

A

void direct exposure to beam

Peak power 2 m

W

Wavelength 1310 n

m

Class 1 LASER Product

Invisible LASER radiation-

3820-rwt & 3820-rwr.ib.rev0.doc Page 2 of 11 28/02/2006

RWT-3820 / RWR-3820

L BAND RF FIBRE OPTIC LINK

Instruction Manual

Table of Contents

Section Page

Operational Safety 3

General description 4

Technical specifications 5

Pre-installation 6

Installation 7

RWT-3820 LASER transmitter module 7

RWR-3820 photo-diode receiver module 8

Front and rear layouts 9

Maintenance & storage 10

Warranty & service 10

Equipment return 10

Drawing index 11

This instruction book applies to serial numbers later than S/N: 0410001

3820-rwt & 3820-rwr.ib.rev0.doc Page 3 of 11 28/02/2006

Operational Safety:

WARNING

Operation of electronic equipment involves the use of voltages and currents that

may be dangerous to human life. Note that under certain conditions dangerous

potentials may exist in some circuits when power controls are in the OFF position.

Maintenance personnel should observe all safety regulations.

Do not make any adjustments inside equipment with power ON unless proper

precautions are observed. All internal adjustments should only be made by suitably

qualified personnel. All operational adjustments are available externally without the

need for removing covers or use of extender cards.

Optical Safety

The light emitted from the LASER diode used in this system is

invisible and may be harmful to the human eye. Avoid looking

directly into the fibre optic cable or connectors or into the

collimated beam along their axis when the device is in operation.

Operating the LASER diode outside of its maximum ratings may

cause device failure or a safety hazard.

DANGER

A

void direct exposure to beam

Peak power 2 m

W

Wavelength 1310 nm

Class 1 LASER Product

Invisible LASER radiation-

3820-rwt & 3820-rwr.ib.rev0.doc Page 4 of 11 28/02/2006

IRT Eurocard

RWT-3820 / RWR-3820

L BAND RF FIBRE OPTIC LINK

General description

The IRT RWT-3820 / RWR-3820 Wide Band RF Fibre Optic Link is a modular system for transmitting broadband

RF ‘L’ band FM modulated signals over an optical fibre cable. The system response is from 900 - 2150 MHz.

The link is designed for transferring the down converted ‘L’ band signals from satellite dishes to main equipment

buildings. Fibre optic cable provides low signal attenuation with no gain or cable equalisation requirements with the

added benefit of immunity to RFI and EMI and protection against lightning strikes.

The system is designed for single mode fibre (9/125 µm) at 1300 nm with a path loss of up to 12 dB. The operating

distance will depend upon the actual cable and connector losses.

RF signal connections are made to 75Ω SMC connectors on the rear panels. BNC and F adapters are provided.

Optical connections are made to SC/PC optical connectors on at the rear of the module.

Modules can be installed in IRT 1 RU or 3 RU frames.

RWT-3820 Laser Transmitter.

Wide band amplifiers are used to drive the DFB LASER with the RF signals applied to the module input. The signal

level is set by a front panel control for optimum signal to noise ratio. A pilot signal is added to the RF path to

monitor the RF path integrity at the receiver.

Pilot signal level and laser output LED indicators are provided as well as a relay contact set for external alarm

indication of laser power or DC supply loss.

LNB power can be applied through a connector on the rear panel.

RWR-3820 Photo-diode Receiver.

The receiver consists of an optical detector diode module followed by an adjustable gain stage and amplifiers to

provide two RF outputs from the receiver.

The output signal level is adjusted to the required level as seen at the RF Mon connector. This level is the same as

the rear output signal level.

Pilot and optical signal level LED indicators are provided as well as a relay contact set for external alarm indication

of optical signal, pilot or DC supply loss.

NOTE: Direct connections are made to the rear of the RWT-3820 and RWR-3820 modules for the

OPTICAL and RF cabling, these must be disconnected when a module is to be mounted or removed from the

IRT Eurocard mounting frame.

3820-rwt & 3820-rwr.ib.rev0.doc Page 5 of 11 28/02/2006

RWT-3820 / RWR-3820 Technical specifications

RF signal connections 75Ω SMC on module rear panel. (BNC and F adapters provided).

RF Monitor connections BNC connectors on transmitter and

receiver front panels.

Allows easy setting up of RF levels.

RF input level Adjustable in the range

-40 dBm to -20 dBm total power.

RF output level Adjustable in the range

-45 dBm to –20 dBm total power.

Input / output VSWR < 2: 1 (75 Ω).

System frequency response 900MHz to 2150 MHz operation.

500 MHz flatness ± 1.5 dB.

36 MHz flatness ± 0.5 dB.

System group delay ±2 ns 900 MHz - 2150 MHz.

Carrier to noise > 26 dB for 36 MHz bandwidth.

Intermodulation products. < 40 dBc.

Tx optical output power 0 dBm.

Rx optical input power -5 dBm to –15 dBm.

(Note: 10 dB pad provided for back to back operation where path attenuation

is less than 5 dB).

System optical budget 12 dB.

Optical signal connections SC/PC (accessible from the rear of the module) for use with single mode

(9/125 µm) fibre cable.

LNB power supply 13 or 18V input to rear panel, SK3,

can be applied.

Power Requirements 28 Vac CT (14-0-14) or ±16 Vdc

Power consumption 6 VA for RWT-3820 and 5 VA for RWR-3820

Mechanical Suitable for mounting in IRT 19" rack chassis with optical, RF & alarm

connections at the rear.

Finish: Front panel Grey with black lettering & red IRT logo.

Rear assembly Detachable silk-screened PCB with direct mount connectors to Eurocard and

external signals.

Dimensions 32 mm x 3 U x 220 mm IRT Eurocard.

Optional accessories TME-6 module extender card.

N

NO

OT

TE

E:

:

A

Al

ll

l

t

th

he

e

p

pa

ar

ra

am

me

et

te

er

rs

s

s

sp

pe

ec

ci

if

fi

ie

ed

d

a

ar

re

e

o

on

nl

ly

y

a

ap

pp

pl

li

ic

ca

ab

bl

le

e

w

wh

he

en

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us

si

in

ng

g

s

si

in

ng

gl

le

e

m

mo

od

de

e

(

(9

9/

/1

12

25

5

µ

µm

m)

)

f

fi

ib

br

re

e

c

ca

ab

bl

le

e

w

wi

it

th

h

a

a

r

re

et

tu

ur

rn

n

l

lo

os

ss

s

o

of

f

≥2

27

7

d

dB

B.

.

Due to our policy of continuing development these specifications are subject to change without notice.

3820-rwt & 3820-rwr.ib.rev0.doc Page 6 of 11 28/02/2006

Pre-installation:

Handling:

This equipment may contain or be connected to static sensitive devices and proper static free handling precautions

should be observed.

Where individual circuit cards are stored, they should be placed in antistatic bags. Proper antistatic procedures

should be followed when inserting or removing cards from these bags.

Power:

AC mains supply: Ensure that operating voltage of unit and local supply voltage match and that correct rating

fuse is installed for local supply.

DC supply: Ensure that the correct polarity is observed and that DC supply voltage is maintained within

the operating range specified.

Earthing:

The earth path is dependent on the type of frame selected. In every case particular care should be taken to ensure

that the frame is connected to earth for safety reasons. See frame manual for details.

Signal earth: For safety reasons a connection is made between signal earth and chassis earth. No attempt should be

made to break this connection.

3820-rwt & 3820-rwr.ib.rev0.doc Page 7 of 11 28/02/2006

Installation

NOTE: Direct connections are made to the rear of the RWT-3820 and RWR-3820 modules for the OPTICAL

and RF cabling, these must be disconnected when a module is to be mounted or removed from the IRT Eurocard

mounting frame.

Installation in frame or chassis:

See details in separate manual for selected frame type.

RWT-3820 LASER transmitter module

The RWT-3820 is factory preset for a optical output of 0 dBm and a RF input level of –40 dBm to –20 dBm.

Installation requires the unit to be plugged into the front of the selected IRT frame and the rear assembly to be

secured to the rear panel of the IRT frame. To install the module in a 1RU or 3RU frame please see the separate

instruction manual “Frames & PSU’s”.

RF signal connection is made to the 75 ohms SMC connector on the rear panel of the RWT-3820, adapters are

supplied to allow connection to circuits using BNC or F series connectors.

A RF signal monitor connector is provided on the front panel. The RF level at this connector should be –40dBm as

adjusted by the front panel RF gain control RV1. At this RF level the laser modulation is set for the best signal to

noise and inter-modulation of the transmission system. For a input signal of –40dBm the RF gain control will be at

the maximum (fully clock-wise) position, for higher input levels the gain will have to be backed up and adjusted to

set the level at the RF monitor connector to –40dBm. Note: the RF Monitor connector will need to be

terminated with the 75 ohms termination provided when not in use.

Optical signal connection is made to the SC/PC optical connector on the rear of the RWT-3820. Extreme care

must be taken to ensure the cleanliness and consequently the best return loss of the optical connections.

The optical output power is monitored by comparator circuits, which are adjusted to change state if the output level

varies by more than ± 3dB from the output level set during alignment. A led indicator on the front panel will light

green when the laser is operating normally and change to red if the laser power deviates by ± 3dB from the pre-set

level.

The RWT-3820 includes a pilot tone generator at 10.7 MHz. This allows for the verification of the RF signal path at

the receiver. A led indicator on the front panel will light green when the pilot is operating normally and change to

red if the pilot signal fails.

The alarm circuit accepts signals from the laser power low always, from the laser power high on LK1 closure and

pilot fail circuit on LK2 closure to operate relay RL1. External connections from the alarm relay are available on

pins 2 and 3 of SK4 on the rear panel. The alarm circuit is wired to give a relay contact closure when a fault

condition such as power failure, low or high optical output, failure of the pilot tone generator occurs. A second

alarm contact closure is available at J3.

LNB power can be applied to the RF in cable through J3 on the rear panel after closing LK5.

3820-rwt & 3820-rwr.ib.rev0.doc Page 8 of 11 28/02/2006

RWR-3820 photo-diode receiver module

The RWR-3820 is factory preset for use with the accompanying RWT-3820 transmitter and an optical path

attenuation of 2 dB, to give unity gain in the RF signal path.

Installation requires the unit to be plugged into the front of the selected IRT frame and the rear assembly to be

secured to the rear panel of the IRT frame. To install the module in a 1RU or 3RU frame please see the separate

instruction manual “Frames & PSU’s”.

RF signal connection is made to the SMC connector on the rear of the RWT-3820, adapters are supplied to allow

connection to circuits using BNC or F series connectors

Optical signal connection is made to the optical connector on the rear panel of the RWR-3820. Extreme care

must be taken to ensure the cleanliness and consequently the best return loss of the optical connections.

To overcome any optical path loss the RF signal level can be set using the front panel gain control (RV3), while at

the same time monitoring the output level using the front panel RF monitor connector which outputs the same RF

level as the rear output connector. Note: the RF Monitor connector will need to be terminated with the 75 ohms

termination provided when not in use.

The optical input signal level is monitored by a current sense and comparator circuit, which is adjusted to change

state if the optical path loss exceeds the maximum optical budget by 3 dB.

The alarm circuit accepts signals from the optical level on LK1 closure and pilot fail circuits on LK2 closure to

operate relay RL1. The external connections for the alarm circuit are available on pins 2 and 3 of SK4 on the rear

panel. The alarm circuit is wired to give a relay contact closure when a fault condition such as power failure or low

optical input occurs. A second alarm contact closure is available at J3.

RWT-3820 adjustments.

RV1 sets the RF modulation level of the laser by applying a bias voltage to the RF attenuator circuit.

RWT-3820 Preset adjustments.

RV2 sets the output LOW indicator circuit as shown by LD3 on the front panel.

RV3 sets the output HIGH indicator circuit as shown by LD3 on the front panel.

RV4 sets the bias current to the laser diode and thus the optical output from the RWT-3820.

RWR-3820 adjustment.

RV3 sets the output RF level of the module by applying a bias voltage to the RF attenuator circuit.

RWR-3820 Preset adjustment.

RV1 sets the pilot SIGNAL LOW alarm circuit threshold as shown by LD2 on the front panel.

RV2 sets the input SIGNAL LOW alarm circuit threshold as shown by LD3 on the front panel.

Diagrams are provided for the RWT-3820 and the RWR-3820. The optical and RF signal sections are housed in

sealed shielded sections containing no user serviceable parts. Should service be required on these circuits, please

return the unit to the supplier for repair and alignment.

3820-rwt & 3820-rwr.ib.rev0.doc Page 9 of 11 28/02/2006

RF Mon.

DC

RWT-3820

N140

RF GAIN

PILOT

LASER

CAUTION

Direct

connections

to module

RF GAIN

PILOT

OPTICAL

DC

RW

R

-3820

N140

RF Mon.

CAUTION

Direct

connections

to module

Front & rear panel connector diagrams

The following front panel and rear assembly drawings are not to scale and are intended to show connection order

and approximate layout only.

L BAND F.O. TX

3

2

1

SK4

OPTICAL

OUT

RF

IN

J3

2

1

SK3

A

larm

A

larm

LNB

DC

IN

L BAND F.O. RX

3

2

1

SK4

OPTICAL

IN

RF

OUT

J3

Alarm

Alarm

3820-rwt & 3820-rwr.ib.rev0.doc Page 10 of 11 28/02/2006

Maintenance & storage

Maintenance:

No regular maintenance is required.

Care however should be taken to ensure that all connectors are kept clean and free from contamination of any kind.

This is especially important in fibre optic equipment where cleanliness of optical connections is critical to

performance.

Storage:

If the equipment is not to be used for an extended period, it is recommended the whole unit be placed in a sealed

plastic bag to prevent dust contamination. In areas of high humidity a suitably sized bag of silica gel should be

included to deter corrosion.

Where individual circuit cards are stored, they should be placed in antistatic bags. Proper antistatic procedures

should be followed when inserting or removing cards from these bags.

Warranty & service

Equipment is covered by a limited warranty period of three years from date of first delivery unless contrary

conditions apply under a particular contract of supply. For situations when “No Fault Found” for repairs, a

minimum charge of 1 hour’s labour, at IRT’s current labour charge rate, will apply, whether the equipment is within

the warranty period or not.

Equipment warranty is limited to faults attributable to defects in original design or manufacture. Warranty on

components shall be extended by IRT only to the extent obtainable from the component supplier.

Equipment return:

Before arranging service, ensure that the fault is in the unit to be serviced and not in associated equipment. If

possible, confirm this by substitution.

Before returning equipment contact should be made with IRT or your local agent to determine whether the

equipment can be serviced in the field or should be returned for repair.

The equipment should be properly packed for return observing antistatic procedures.

The following information should accompany the unit to be returned:

1. A fault report should be included indicating the nature of the fault

2. The operating conditions under which the fault initially occurred.

3. Any additional information, which may be of assistance in fault location and remedy.

4. A contact name and telephone and fax numbers.

5. Details of payment method for items not covered by warranty.

6. Full return address.

7. For situations when “No Fault Found” for repairs, a minimum charge of 1 hour’s labour will apply,

whether the equipment is within the warranty period or not. Contact IRT for current hourly rate.

Please note that all freight charges are the responsibility of the customer.

The equipment should be returned to the agent who originally supplied the equipment or, where this is not

possible, to IRT direct as follows.

Equipment Service

IRT Electronics Pty Ltd

26 Hotham Parade

ARTARMON

N.S.W. 2064

AUSTRALIA

Phone: 61 2 9439 3744 Fax: 61 2 9439 7439

Email: service@irtelectronics.com

3820-rwt & 3820-rwr.ib.rev0.doc Page 11 of 11 28/02/2006

Drawing index

Drawing # Sheet # Description

804800s1 1 RWT-3820 schematic diagram – sheet 1

804797s1 1 RWR-3820 schematic diagram – sheet 1

Title

SCALE

SIZE

Sheet

DRAWN

CHECKED

ENG. APP.

Revision:

DO NOT COPY NOR

DISCLOSE TO ANY

THIRD PARTY

WITHOUT WRITTEN

CONSENT

of1

IRT Electronics Pty. Ltd.

Drawing No.

COPYRIGHT

ARTARMON NSW AUSTRALIA 2064

A3

N.T.S. 5

RWT-3820

804800

Date:

1

27-Feb-2006

K.N.

1 17-07-03

ALARM

Laser RF

Laser circuit

804800s2.sch

J2 optional power in

(used when fitted to FRU-1030 frame)

1

2

3J2

SK1

AC 1

AC 4

AC 2

AC 3

Power Supply Circuit

804800s5.sch

31

2

LK3

'DC'

grn

12

R71

680R

21

LD1

+12V

n.c.

n.o.

1 3

2

D12

BZX84C12

-5V

1A

1B

2A

2B

3A

3B

4A

4B

5A

6A

6B

7A

7B

8A

8B

10A

10B

5B

11A

11B

12A

12B

13A

13B

14A

15A

15B

17A

17B

18A

18B

9A

9B

20A

20B

14B

21A

21B

22A

22B

23A

24B

24A

25B

26A

27A

27B

28A

23B

19A

19B

30A

30B

26B

31A

31B

32A

32B

25A

16A

16B

28B

29A

29B

P1

DIN64RA

1 2

C38

100nF

+12V

Laser RFRF Input

RF Mon.

Pilot

Pilot Present

LNB Power

RF circuit

804800s3.sch

PilotPilot Present

Pilot Generator

804800s4.sch

SK2

RF IN

RF MON.

L-Band Fibre Optic Tx.

1

2J3

LASER

PILOT

GAIN

MON.

DC

21

LK2

1A

1B

2A

2B

3A

3B

4A

4B

5A

6A

6B

7A

7B

8A

8B

10A

10B

5B

11A

11B

12A

12B

13A

13B

14A

15A

15B

17A

17B

18A

18B

9A

9B

20A

20B

14B

21A

21B

22A

22B

23A

24B

24A

25B

26A

27A

27B

28A

23B

19A

19B

30A

30B

26B

31A

31B

32A

32B

25A

16A

16B

28B

29A

29B

J1

DIN64

2 1

D13

LS4148

1

2SK3

LNB DC INPUT

Alarm Logic

Rear Panel

Alarm Relay Contacts

13

2D8

BAT54

Rear Panel

Front Panel

'Laser On'

grn

1 2

R69

680R

+12V

red

'Alarm'

1

3

2

LD3

L-3WEGW

1 2

R68

10K

1 2

R70

10K

red

grn

1

2

3com.

1

32

Q13

BC846

1

32

Q12

BC846

32

1

Q11

BSS123

112

RL1A

FBR46ND012

7

8

10

RL1C

31

2

LK4

n.c.

n.o.

6

5

3

RL1B

'Pilot On'

grn

1 2

R66

680R

+12V

red

'Alarm'

1

3

2

LD2

L-3WEGW

1 2

R65

10K

1 2

R67

10K

red

grn

1

2

3com.

1

32

Q10

BC846

1

32

Q9

BC846

32

1

Q8

BSS123

1

2

3SK4

2 1

LK5

1 2

C70

0.1uF

21

D10

LS4148

21

D9

LS4148

1 3

2

D7

BAT54

1

32

Q4

BC846

1 2

R33

10K

+12V

(1B)

(Y2)

(L4)

(L4)

Title

SCALE

SIZE

Sheet

DRAWN

CHECKED

ENG. APP.

Revision:

DO NOT COPY NOR

DISCLOSE TO ANY

THIRD PARTY

WITHOUT WRITTEN

CONSENT

of1

IRT Electronics Pty. Ltd.

Drawing No.

COPYRIGHT

ARTARMON NSW AUSTRALIA 2064

A3

N.T.S. 1

RWR-3820

804797

Date:

1

27-Feb-2006

K.N.

Signal

Pilot

RF Out

RF Mon.

Detector circuit

804797s2.sch

J2 optional power in

(used when fitted to FRU-1030 frame)

1

2

3J2

SK1

AC 1

AC 4

AC 2

AC 3

Power Supply Circuit

804797s4.sch

31

2

LK3

'DC'

'grn'

1 2

R9

680R

+12V

n.c.

n.o.

1 3

2D3

BZX84C12

-5.2V

1A

1B

2A

2B

3A

3B

4A

4B

5A

6A

6B

7A

7B

8A

8B

10A

10B

5B

11A

11B

12A

12B

13A

13B

14A

15A

15B

17A

17B

18A

18B

9A

9B

20A

20B

14B

21A

21B

22A

22B

23A

24B

24A

25B

26A

27A

27B

28A

23B

19A

19B

30A

30B

26B

31A

31B

32A

32B

25A

16A

16B

28B

29A

29B

P1

DIN64RA

1 2

R10

4K7

+12V

Pilot InPilot Present

Pilot Detector

804797s3.sch

SK2

RF OUT

RF MON.

L-Band Fibre Optic Rx.

1

2J3

OPTICAL

PILOT

GAIN

MON.

DC

1A

1B

2A

2B

3A

3B

4A

4B

5A

6A

6B

7A

7B

8A

8B

10A

10B

5B

11A

11B

12A

12B

13A

13B

14A

15A

15B

17A

17B

18A

18B

9A

9B

20A

20B

14B

21A

21B

22A

22B

23A

24B

24A

25B

26A

27A

27B

28A

23B

19A

19B

30A

30B

26B

31A

31B

32A

32B

25A

16A

16B

28B

29A

29B

J1

DIN64

2 1

D7

LS4148

1 10-01-02

+12V

'Pilot'

grn

1 2

R12

680R

red

'Alarm'

1

3

2

LD2

L-3WEGW

1 2

R11

10K

1 2

R13

10K

red

grn

1

2

3com.

13

2

D1

BAT54

13

2

D2

BAT54

1

32

Q4

BC846

1

32

Q3

BC846

32

1

Q2

BSS123

'Signal'

grn

1 2

R15

680R

+12V

red

'Alarm'

1

3

2

LD3

L-3WEGW

1 2

R14

10K

1 2

R16

10K

red

grn

1

2

3com.

1

32

Q7

BC846

1

32

Q6

BC846

32

1

Q5

BSS123

Alarm Logic

Alarm Relay

Rear Panel

Front Panel

21

LK1

21

LK2

Rear Panel

1

32

Q1

BC846

112

RL1A

FBR46ND012

7

8

10

RL1C

31

2

LK4

n.c.

n.o.

6

5

3

RL1B

1

2

3SK4

21

D4

LS4148

21

D5

LS4148

1 2

C13

100nF

21

LD1

HLMP-1503

Contacts

BC846B (1B)

BSS123 (SA)

(1B)

+12