80-7061N Issue 3 RT9 service manual · 2020. 3. 6. · i ENA Telecommunicaciones Respondedor Radar...

RT9 SART

Service Manual

80-7061M

Commercial in confidence 80-7061M

SART service manual Issue 3

Table of Contents

1. Introduction ......................................................................................................... 1 1.1. Scope ............................................................................................................... 1 1.2. Applicability ....................................................................................................... 1 1.3. Revision history ................................................................................................ 1 1.4. Servicing equipment ......................................................................................... 3 1.5. Safety notices ................................................................................................... 4

2. Assessment ......................................................................................................... 7 2.1. Maintenance tasks ............................................................................................ 7 2.2. Routine testing .................................................................................................. 7 2.3. Assessment ...................................................................................................... 8

3. Maintenance procedures .................................................................................. 10 3.1. Identification of SART version ........................................................................ 10 3.2. Mechanical inspection .................................................................................... 10 3.3. Self test procedure.......................................................................................... 11 3.4. Functional testing............................................................................................ 12 3.5. Frequency testing ........................................................................................... 13 3.6. Leak testing .................................................................................................... 15 3.7. Battery replacement ........................................................................................ 16

4. Fault finding ....................................................................................................... 20 5. Repair procedures ............................................................................................. 21

5.1. Replace O-rings .............................................................................................. 21 5.2. Replace indicator board .................................................................................. 22 5.3. Replace microwave module ............................................................................ 23 5.4. Re-tune microwave module ............................................................................ 24 5.5. Factory return procedure ................................................................................ 26

6. Spares ................................................................................................................ 27 Appendix 1: Specification ....................................................................................... 28 Appendix 2: COMSAR recommendations ............................................................. 29

This document is Orolia Ltd copyright (©) and contains proprietary owned intellectual property rights and confidential data. All rights are strictly reserved. The information must not be used except for the agreed purpose. Unauthorised use, reproduction or issue to any third party is not permitted without the prior written authority of Orolia Ltd. This document is to be returned to Orolia Ltd when the agreed purpose is fulfilled.


SART service manual Issue 3


SART service manual Issue 3 Page 1

1. INTRODUCTION The Search and Rescue Radar Transponder (SART) is a rescue aid designed to detect an X-band marine radar signal and produce a distinctive radar return pulse which causes a series of radial dots to appear on the remote radar screen. These dots are recognised as a “distress” pattern and assist in the location of the SART.

The SART works with any radar operating between 9.2 and 9.5GHz. It has a broadband receiver that detects any incoming radar pulse and “triggers” the SART. Once triggered, the SART switches to transmit mode and responds with 12 sweeps across the entire 9.2 to 9.5GHz radar band. At some point in each sweep the frequency will “hit” the radar’s receiver band and produce a simulated 'echo'. A total of 12 'echoes' are produced as a radial line on the radar screen, the innermost 'echo' being the approximate position of the SART.

The SART thus has three modes of operation :

Off – all functions are disabled. This is the storage condition. Standby – the unit is active, and ready to respond to a detected signal. Transmit – a signal has been detected and the unit is responding.

After approx. 15 – 18 seconds of seeing no incoming radar pulses, the SART will revert to standby mode to save power.

1.1. Scope This manual represents the original equipment manufacturer’s (OEM) documentation applicable to the SART equipment listed below. The manual provides complete instructions for shore-based maintenance (SBM) providers to enable routine servicing of these products. 1.2. Applicability This information applies to the following SART models. All of these are “badged” versions of the basic RT9 SART.

i ENA Telecommunicaciones Respondedor Radar (RR) i Marconi Marine Salvare 6 i McMurdo RT9 i Nova Marine RT900 i Pains Wessex SOS SART i SAILOR SART i SAIT SF4251 i SEA 20

1.3. Revision history The RT9 was first produced in 1992 and has been through 4 major revisions, called the Mk1, Mk2, Mk2.5 and Mk3. The Mk3 being the current production item and dominating in terms of quantities sold. The diagram overleaf is a summary of the revision history to date.



RT9 REVISION HISTORY

The symbol indicates the battery type currently available for this model Support Although, the basic external casing shape has changed little over the years, each revision involved significant internal changes to the microwave module, the indicator board and the battery type.

Spares availability for the earlier versions such as the Mk1, Mk2 and Mk2.5 is limited. Replacement batteries are available, as are plastic parts. However, any internal electronic faults will render the SART unserviceable.

The Mk3 is still fully supported. See section 6 for the available spares list.

As the Mk3 dominates in terms of quantities sold, this manual only covers servicing of the Mk3. The procedures are however valid for earlier versions, although internal parts may vary in appearance.

1992 1993 1995 1996 1997

Jan-92MK1 S/N 0001 - 3999

80-D192 (760-00Z-X003)80-D194 (Japan only)

Jan-94MK2 (S/N 4000 - 4999)

80-D160 (761-00Z-X010)

MK2.5 S/N 5000 - 999980-D142 (762-00Z-X004)80-D140 (Japan) (762-00Z-X004)

MK3 early (S/N 30000 - 30999)80-D163 (763-00Z-X020)

MK3 orange S/N 31000 on80-D160 (761-00Z-X010)

MK3 yellow80-D165

S/N = Serial Numbers

Aug-94

1994

Jan-94

Aug-94

Aug-94 Sep-94

May-94

1998 1999

Jun-99

Jun-99

Aug-98



1.4. Servicing equipment Detailed SART servicing requires much specialist equipment, including a microwave pulse generator and a spectrum analyser. To reduce equipment costs a dedicated SART tester (ARG 5420) is now available. Traditionally this equipment is beyond the reach of many service agents and a lower level of routine SART servicing has become normal. This just requires access to a marine X-band radar to trigger the SART and view its response on the radar screen. For many service agents, located near a harbour this facility can be arranged with local boat owners. The level of equipment required can thus be broken into two categories: Equipment for advanced servicing:

a) 9.4GHz pulse generator with suitable horn antenna 10GHz spectrum analyser (accurate to 20MHz) with Rx antenna or b) ARG 5420 dedicated SART tester

Equipment for routine servicing: Marine X-band Radar within 2 miles (or access to this)

Leak test facility (made on site as required) Static safe work area with operator wrist strap Battery discharge circuit (made on site as required) Tin can for screening SART radome Multi-meter

Handtools: 6mm flat bladed screwdriver with 20cm (8”) reach 3mm flat bladed screwdriver small cross-headed screwdriver Torque driver with 2mm hex (allen) bit Silicone or Lithium based grease Antistatic precautions The electronics section of the SART is sensitive to electrostatic discharge (ESD). ESD can cause immediate or hidden long term damage. It is important that the PCBs are only handled under suitable antistatic conditions.

Ideally, a fully grounded workstation, which has conductive surfaces to avoid the build up of static charge, should be used. As a minimum, the operator must be connected to a good earth point through a resistance of 1Mohm. This is usually achieved by wearing a suitable wrist strap.



1.5. Safety notices Please read the following for your safety: This product has been assessed as presenting negligible hazard in a sealed serviceable state. Safety analysis The following table summarises the nature of the hazard which may be present when the unit is opened or serviced; each hazard is discussed at greater length in the detailed sections. Hazard cause Hazard identification Precautions Lithium battery Explosive risk, corrosive fumes,

fire, biological hazard Handle appropriately, avoid contact

Radio frequency radiation

Physiological hazard Avoid close or prolonged exposure

Adhesives Skin irritation, fumes Avoid contact, ventilate well IPA Irritation, highly flammable Avoid contact, ventilate well Silicone grease Skin irritation (low risk) Avoid contact Lithium batteries

Hazardous chemicals Wear gloves The batteries used in these products contain Lithium (Li). Lithium is inflammable, reacts violently with water and constitutes a biological hazard. These batteries are HAZARDOUS if short-circuited, punctured, incinerated or deformed. Lithium batteries must not be short circuited. Lithium batteries must be handled, transported and disposed of using appropriate safety precautions. The use of rubber gloves as a routine precaution is recommended. In the event of leakage of the battery electrolyte (which can be recognised by a pungent odour), take care to avoid contact, particularly with open wounds; do not ingest the material. Do not attempt to discharge a leaking battery – remove it using appropriate handling materials and seal in a plastic bag, then dispose of it through an approved environmental disposal agent, or in accordance with local regulations.



Radio frequency radiation

Radio frequency radiation A SART produces microwave radiation when it responds to a radar. The radiated level is below 2W with a duty cycle below 1%. The low duty cycle means this is not considered to be a hazard General precautions for chemical agents (adhesives, greases, IPA) Observe all safety precautions relevant to the country of operation. As a general rule, protective overalls, gloves and goggles should be worn when handling these chemical agents, but different countries may have additional requirements which must be observed. Ensure that all chemical agents are handled in accordance with the manufacturer's instructions, and that suitable protective clothing is worn. Make sure that the working area is well ventilated, and that chemical substances are not left exposed. Observe good hygiene practices; do not eat, drink or smoke when handling chemicals. Cyanoacrylate adhesives bond instantly on contact. If skin is bonded, it can usually be released by a gentle peeling action; above all, do not panic and avoid direct pulling on bonded skin. Read the manufacturer's instructions before using any chemical agent.

Wear goggles Wear overalls Wash hands Wear gloves





2. ASSESSMENT 2.1. Maintenance tasks Service agents (Shore Based Maintenance (SBM) providers) are reminded that it is their responsibility to ensure that good common practice and the procedures herein are followed and that only Orolia Ltd approved parts are fitted.

Routine service agents can provide: i Assessment i Functional test i Leak test i Battery replacement

Advanced service agents can also provide: i Microwave testing i Frequency adjustment

2.2. Routine testing Every SART should be tested monthly by its owner to ensure its functionality.

Whenever possible the SART should be inspected for mechanical damage.

It is strongly recommended that the SART be functionally tested using a radar signal every two years, as recommended in the COMSAR guidelines (see Appendix). The SART should not be opened during this test. An approved service label showing the date of test should be affixed to the outside of the SART.

Every time the batteries are replaced, the SART must receive a functional test and a leak test, as shown in the table below. Frequency of testing: INTERVAL PERFORMED BY Self test Function test Leak test Monthly ´ Customer 2 years ´ ´ Customer or SBM provider Battery change ´ ´ ´ SBM provider



2.3. Assessment Every SART returned for servicing, of whatever nature, must be fully assessed to determine its operational status. The diagram shows the tasks which must be carried out for each servicing situation. This must include a functional test and a leak test.

Assessment form The assessment form overleaf serves as a prompt to ensure no assessment steps are left out. It may be used to support customer billing, and must accompany any warranty return to the manufacturer.

It is important that as much information as possible is recorded on the form. Procedures for the assessment are detailed in section 3.

ASSESSMENTInspectSelf test

Receipt

Functional test

Return

No fault

Leak test

Disassemble

Changebattery

Reassemble

Disassemble

Repair

Reassemble

Battery change Fault found

Leak test



RT9 SART ASSESSMENT Ref No.

Serial No. MK1 x MK2 x MK2.5 x MK3 x

Customer/Comments

Date.

Inspection Remarks Casing intact YES NO Mast intact YES NO Mast extends correctly YES NO Lanyard attached YES NO Switch guard in place YES NO Tamper seal intact YES NO Battery expiry date OK YES NO Date:

Self test

Un-triggered state PASS FAIL Triggered state PASS FAIL Functional test PASS FAIL

Frequency test results

Upper frequency (9.53+0.03MHz)

PASS FAIL Value: MHz

Lower frequency (9.17+0.03MHz)

PASS FAIL Value: MHz

Number of sweeps (12+1)

PASS FAIL Value: sweeps

Pulse length (95+13us)

PASS FAIL Value: us

Battery voltage PASS FAIL Value: volts

Leak test (if opened) PASS FAIL

Name of tester Signature

Date

Conclusions Spares: Mast x

Bracket x Lanyard x

Switch guard x Tamper seal x

Microwave module x Indicator board x

Sealing kit x Battery kit x



3. MAINTENANCE PROCEDURES 3.1. Identification of SART version The serial number of the individual SART is the only accurate means of identifying whether it is a Mk1, Mk2, Mk2.5 or Mk3. The serial number is currently marked on the label fitted to the central section of the SART (see picture). Earlier models, were marked on the upper radome section. The serial number is of the form RT9/YYXXXXX. Where YY represents the year of manufacture and XXXXX is the serial number used for identification.

Part of SART central label

Identification chart

Serial Number Version Colour 0001 – 3999 MK1 Orange 4000 – 4999 MK2 Orange 5000 – 9999 MK2.5 Orange 30000 – 30999 MK3 (early) Orange 31000 – 50999 MK3 Orange 51000 - 70999 MK3 Yellow

3.2. Mechanical inspection

Casing Ensure there are no visible cracks or mechanical damage. A cracked casing will lead to water ingress and is a serious fault.

Mast Confirm the mast is intact and in good condition. The mast should be checked by removing the cap from the top of the mast tube and checking that the sections can be extended smoothly, and that they lock into position. Ensure that the mast is fully stowed after inspection, and that the end cap is secure.

Lanyard The lanyard must be securely attached to the SART. Where the bracket has been returned, check that the lanyard is not attached to any part of the bracket. Check that the test probe is fitted in the hole on the right side of the bracket.

Switch guard If the switch guard is missing then replace it.

Tamper seal A broken tamper seal means that battery condition is suspect. Establish if SART has been used. If so then fit a new battery.

Battery expiry Note the expiry date. If there is less than 6 months left contact

Serial number

ONDERWARNING

EMERGENCY USE ONLY

STANDBY TRANSMIT

FLASHING STEADY LIGHTBEEPLIGHT

Ser No. RT9/YYXXXXX



vessel and advise that they will need a new battery. 3.3. Self test procedure CAUTION: Only test for the minimum time possible.

A live distress call may be received by other vessels within range.

Equipment A non-metallic test probe is required. Test probes are part numbers 80-4012 (‘thin’), 80-4019 and 80-4021 (both ‘thick’). The appropriate probe must be used, as shown in the table:

Serial Number Version Probe Part No. 0001 – 3999 MK1 Thick 80-4021 4000 – 4999 MK2 Thin 80-4012 5000 – 9999 MK2.5 Thin 80-4012 30000 – 30999 MK3 (early) Thin 80-4012 31000 – 50999 MK3 Thick 80-4021 51000 – 70999 MK3 Thick 80-4019

Testing requires a signal to trigger the SART out of standby and into active mode. This can be supplied by :-

i An X-band marine radar operating nearby (within 3 miles) i A dedicated SART tester (ARG 5420) i A 9.35GHz microwave pulse generator, set for 1us pulse every 1ms.

In addition, to prove that the SART returns to standby mode, the signal must either be turned off (SART tester or pulse generator) or the SART upper section (radome) can be covered with a metal container – a can of suitable size works well. Test procedure 1. Turn trigger signal off or cover radome with can 2. Insert test probe into 3mm hole in centre of ON/OFF button (do not damage label) 3. Push firmly until ON/OFF button snaps ON (see IMPORTANT NOTE below) 4. Confirm SART indicates standby mode as per table below

Version Standby Transmit MK1 Lamp flashes and beeper sounds

every 12 seconds Lamp flashes and beeper sounds every 2 seconds

MK2 MK2.5 MK3

LED flashes every 2 seconds Beeper is off

LED is on continuously Beeper sounds every 2 seconds

5. Turn trigger signal on, or uncover radome, check transmit is indicated (see above) 6. Turn trigger signal off or cover radome. Confirm that standby indication returns Note : A delay of 20 seconds is normal after signal is removed 7. Push probe into 6mm rear hole (see pictures) until on/off button snaps forward 8. Ensure switch guard is still properly seated over on/off button IMPORTANT NOTE: The above procedure is for Mk1 and Mk3 versions.

The procedure for Mk2, Mk2.5 and Mk3 (early) versions is similar, except i The test probe moves a spring loaded plunger, so it is NOT necessary to

snap the on/off button.



i The SART deactivates when the test probe is removed. It is NOT necessary to push the button back using the rear hole.

Test probe position to start self test and to stop self test 3.4. Functional testing CAUTION: Only test for the minimum time possible.

A live distress call may be received by other vessels within range.

This test involves observing SART transmissions and can be done two ways:

i Using a dedicated SART tester (ARG 5420). See section 3.5. i Using a nearby radar and observing the radar screen. Explained here.

Procedure 1. Locate SART as far from radar as is practical. A minimum of 20m is advised. 2. Activate SART in self-test mode. See section 3.3 for details. 3. Hold SART upright so that it has line of sight to the radar antenna. 4. The SART should indicate “active” mode. 5. Confirm the radar screen shows typical SART echoes. 6. De-activate the SART as quickly as possible. Observations The SART response is a series of 12 pulses, which is displayed on a radar as a number of echoes spaced approximately 0.6 nautical miles apart. Ideally, these will be clear dots extending radially outwards, However, close proximity to the radar may result in circular blurring of the display – in extreme cases, a series of concentric circles may be produced. This is quite normal at close proximity and still constitutes a PASS for the functional test.



3.5. Frequency testing Frequency testing is included here as an optional maintenance procedure. It is not required during routine servicing. However, some countries do require testing of the SART frequency sweep limits, in which case this section will be helpful.

To measure the frequency sweep, the SART must be continuously triggered with a suitable microwave signal. The 12 response sweeps are then viewed using either:

a) 9.4GHz pulse generator with suitable horn antenna 10GHz spectrum analyser (accurate to 20MHz) with Rx antenna

b) ARG 5420 dedicated SART tester

Method (a) requires complex configuration and is left to the specialist service agent. Method (b) using the SART tester is simple and is described below. ARG 5420 SART tester The Sartech/ARG 5420 portable SART tester is a hand-held instrument which triggers a SART and measures the resulting response. The frequency spectrum, frequency limits, pulse length and number of sweeps are measured and displayed. Test results may be stored for later recall or they may be printed. Procedure Comprehensive instructions are given in the handbook provided with the equipment; this summary only acts as a reminder to users who are familiar with the instrument.

1. Switch on 5420 and check display. 2. Press F4, press F1 twice. 3. Activate SART. 4. Hold 5420 horizontal, about 300mm (12") from top of SART. 5. Press and hold F1 on 5420 until a consistent spectrum is displayed. 6. De-activate SART. 7. Press F3 twice on 5420 to display PASS/FAIL listing. 8. Press F3 again, then F2 to save the result. 9. Press F4, then enter the SART serial number. 10. Press F4 to store.

Alignment of ARG5420 with SART At close range the signal from the SART is directional. Maximum signal strength is radiated at right angles to the activation switch. Best results will be obtained when the tester is positioned as shown.

ARG5420

SART being tested

300mm (12") approx



SART tester features The SART tester displays the results of the tests in three ways: 1. During and after the test, it displays the response as a graph of amplitude against

frequency – the ‘spectrum analyser’ display. The position of the tester should be adjusted to produce the optimum response – it is desirable to receive the greatest possible strength of signal, but not to saturate the 5420 receiver.

Spectrum analyser display 2. Once the test is complete, pressing F3 on the tester displays the frequency

response of the SART against time, and so shows a series of frequency sweeps. A magnified view (press F1) is shown – note that the SART being displayed sweeps down from 9.5GHz to 9.2GHz. Note the exact limits of the frequency sweep – 9.53 and 9.16 GHz – are displayed on this and the next screen.

Sweep frequency display

3. Pressing F3 again displays the summary results with the PASS/WARN/FAIL

classification.

Summary results



3.6. Leak testing Two alternative methods of leak testing are given. The gross leak test is preferred, as it causes a greater pressure differential across the seals of the SART, and so is more likely to detect a leak. Also, as this is a “positive pressure” test, there is less likelyhood of a leaking SART filling with water.

If the immersion test is used, the repeatability of the weighing scales is critical. A SART weighs approximately 1kg and the pass criterion is a weight gain of less than 1g, hence a repeatability of better than 0.05% is desirable.

The SART floats, so it must be constrained to ensure that it stays submerged. Gross leak test CAUTION: Hot water. Take appropriate protection measures.

1. Immerse the SART in hot water: the ideal temperature is 60º +5ºC; cooler water will not cause a sufficient rise in temperature, hotter water may damage the SART.

2. Dislodge all trapped air from the sealing ring mouldings, the mast stowage fitting and the actuation switch area.

3. For the next five minutes, while keeping the SART submerged check for the escape of bubbles, particularly from the sealing flanges and around the switch actuation apertures.

4. Remove the SART from the water and dry it thoroughly before its temperature drops.

Any escape of bubbles must be corrected by disassembling the SART, replacing or refitting the source of the leak, and re-testing. Immersion pressure test This test checks for a gain in weight caused by the ingress of water. The Lanyard should not be fitted for this test.

1. Weigh the SART on an accurate scale and record the value.

2. Immerse the SART in cold clean fresh water, as deep as possible.

3. Keep the SART submerged for at least 12 hours.

4. Remove the SART from the water and dry it thoroughly. Re-weigh it on the same scale as used previously.

A gain in weight in excess of 1.0g indicates a leak.

Provided that the water is clean and fresh, no damage should be sustained from a leak. Leaking SARTs may be disassembled and dried in an oven (maximum 55ºC), then re-assembled and re-tested.

Hot



3.7. Battery replacement It is essential for safety and the reliability of the equipment that only the correct type of battery is fitted. Use only Orolia Ltd approved parts.

All batteries carry a label showing the replacement battery part number. Later labels also indicate the serial numbers of the SARTs to which the battery may be fitted.

SART battery label Current battery models Serial Number Country Battery Previous type Voltage Connector 0001 – 3999 80-D192 760-00Z-X003 18V 2 way 0001 – 3999 Japan only 80-D194* 760-00Z-X003 18V 2 way 4000 – 4999 80-D160 761-00Z-X010 9V 3 way 5000 – 9999 80-D142 762-00Z-X004 18V† 5 way 5000 – 9999 Japan only 80-D140* 762-00Z-X004 15V 5 way 30000 – 30999 80-D163 763-00Z-X020 9V† 4 way 31000 – 50999 80-D160 761-00Z-X010 9V 3 way 51000 – 70999 80-D165 9V 3 way * Indicates that a battery is classified as HAZARDOUS for transportation purposes.

Obsolete battery models Obsolete type Replacement 80-D193 SART MK1 80-D192 80-D180 (12V)† 80-D163 (9V)† 80-D161 NOVA RT900 80-D160 80-D162 SART MK3 80-D160 80-D164 SEA MK3 80-D160

† In some cases the current battery is not the same voltage as the battery it replaces. In such cases the change in voltage has no effect on SART performance. Battery voltage test Lithium batteries have a very constant discharge voltage over time, hence voltage is not any indication of the capacity remaining in the battery. The only test which can be applied is to measure if this plateau voltage has been reached (as it is slightly lower than the fresh battery voltage) and to assume that the life of the battery has been compromised if this plateau voltage has been reached.

The table below shows the fresh voltage and the minimum acceptable voltage for all current battery models. All voltages are measured open-circuit.

Battery Voltage when fresh

Acceptable Voltage

SART Serial Number

Country

80-D140 16.5 15.0 5000 – 9999 Japan only 80-D142 18.0 16.8 5000 – 9999 80-D160 9.0 8.4 4000 – 4999 80-D160 9.0 8.4 31000 – 50999 80-D163 9.0 8.4 30000 – 30999 80-D165 9.0 8.4 51000 – 70999 80-D192 18.0 16.8 0001 – 3999 80-D194 19.8 18.0 0001 – 3999 Japan only

9V LITHIUM BATTERY

MANU DATE : APR 99REPLACE BY : APR 05

TYPE 80-D160FOR SART SERIAL No's :-

4000 - 4999 & 31000 - 50999



Replacement procedure The replacement battery is supplied as a kit, including the lower plastic moulding and a fresh O-ring seal. It is replaced as a complete item. A leak test must be performed after replacing the battery. All screws are tightened to a torque of 0.5Nm.

1. Unscrew bracket (retain the 3 screws) and remove mast unit and lanyard. 2. Unscrew battery unit, removing the screws in the order

shown. Discard the screws.

3. Carefully separate the Transponder/Switch unit from the battery unit. Do NOT let the clear moulding become unseated from the main body section.

4. Disconnect the battery cable from the circuit board. Use finger nails or a

small screwdriver to release the connector latches without damage. 5. Separate the two parts completely. 6. Discard the ‘O’ ring fitted to the Transponder/Switch flange. 7. Ensure that the replacement ‘O’ ring is clean, then apply a thin coat of

silicone or Lithium based grease to the O-ring and fit it to the flange of the Transponder/Switch unit.

Transponder unit

Battery unit

‘O’ ring goes here

Clear moulding



8. Connect cable of replacement battery unit to the circuit board in the Transponder/Switch unit. Observe polarity of the connector and ensure that the latches engage.

9. Ensure that the clear switch moulding is correctly seated. If it becomes unseated, it may be necessary to re-seat the internal ‘O’ ring.

10. Align the activation switch with the hole in the upper part of the SART, align the battery section so that the mast fitting is below the test probe access hole and mate the two halves as shown below; take care to align the screw holes. Do not rotate the two halves excessively, as this may strain the battery connector. Fit and tighten the replacement screws in the order shown for disassembly. NOTE : It is normal for the O-ring to be a tight fit into the battery moulding.

Front and rear alignment 11. Perform a leak test, as described in section 3.6. 12. Refit the mast unit by inserting sideways as shown. Ensure that the

lanyard is secured to the mast section. 13. Replace the screws securing the mast unit. 14. Carry out self-test procedure.



Disposal of batteries

Hazardous chemicals Wear gloves Lithium battery packs should be discharged slowly, then disposed of through an approved environmental disposal agent, or in accordance with local regulations.

The rate of discharge must not exceed 100mA. A resistor of 100 ohms (2W rating) is satisfactory for a 9V battery. UNDER NO CIRCUMSTANCE MAY THE BATTERY BE SHORT-CIRCUITED.

If the battery shows signs of electrolyte leakage, do not attempt to discharge. Refer to section 1.5 for advice on correct handling.



4. FAULT FINDING Due to the nature of the SART fault finding is limited. The steps shown below should be sufficient to trace the fault to a major sub-assembly, which can then be replaced.

The sequence given below requires that each part is completed satisfactorily before proceeding to the next part. It is, for example, assumed that any faults found at a particular stage are remedied before continuing.

The following diagnostic is applicable to all versions of SART. Fault Cause Action Red LED never on Dead battery Check battery volts

Faulty indicator PCB Replace PCB No standby mode indication SART in active mode Remove input signal

Stuck in active mode New microwave module No active mode indication When SART triggered

Faulty microwave module Or faulty indicator PCB

Replace indicator PCB Then microwave module

LED indicates active mode But beeper does not sound

Faulty indicator PCB Replace PCB or beeper

Frequency limits wrong Drift on microwave module Retune module Faulty microwave module Replace module

Check batteryvoltage OK

Switch on LEDflash

Trigger Beep

Use SART tester PASS

Leak test OK

FAULTY

Despatch

Change battery

Change switch board

Use SART tester PASS

Change microwave

module

Rectify

N

N

N

N

N

N

Y

Y

Y

Y

Y

Y

RETEST

LEDoff

N

Y

Use screeningcan



5. REPAIR PROCEDURES SART repair is by replacement of major sub-assemblies only. No component level diagnostics are provided. The following repairs are possible if required:

i Replace O-rings i Replace indicator PCB i Replace microwave module i Re-tune microwave module

All spares are provided as individual items. See section 6 for a full spares list. 5.1. Replace O-rings The SART uses 3 different O-rings. Replacements must be fitted whenever the SART is opened. All O-rings should be lightly smeared with silicone grease before use. Disassembly and re-assembly procedures are covered in other sections. The diagram below shows the correct O-ring positions.



5.2. Replace indicator board Disassemble the SART as shown in section 3.7 steps 1 through 6.

Remove the six screws retaining the upper radome section of the SART to expose the microwave module and disconnect the lead from the lower board of the module. (It is not advisable to remove the microwave module unless it is being replaced.)

The clear switch moulding can now be removed, along with the middle ‘O’ ring.

The indicator board is secured by hot-melt glue. Break off the glue deposits and free the board from the pillars. Fit the replacement board and secure with hot melt glue.

Replacement indicator board Re-assemble as follows:

Apply a light film of silicone grease to new middle ‘O’ ring (making sure to select the correct size) and place it inside the SART centre section.

Connect the cable between the indicator board and the microwave module. This is an awkward job because of the limited space available to grip the connector. An effective method is to push the connector into place from the open end of the SART.

Refit the battery connector and self test the SART (section 3.3) to ensure that it operates correctly.

Disconnect the battery connector, then follow the procedure in section 3.7 steps 7 to 10, taking care that the middle ‘O’ ring above the switch module is seated correctly.

Apply a light film of silicone grease to the new upper ‘O’ ring and fit it to the top section of the SART. Replace the six screws. Perform a leak test.



5.3. Replace microwave module The microwave module is supplied as a unit, with the circuit boards retained by plastic pillars. Do not remove the pillars until ready to fit the module, as the distance piece between the circuit boards is loose and may become mis-aligned.

Replacement microwave module Module in place on SART It is much easier to fit the connector to the bottom board of the module before removing the pillars. Once the pillars are removed, take care to hold the screws in place as these retain the distance piece correctly.

Remove the top radome section of the SART by unscrewing the six screws. Remove the existing module by unscrewing the two screws which are accessed though holes in the top surface of the microwave antenna. Disconnect the lead from the bottom circuit board, taking care to retain it from falling into the interior of the SART.

Fit the lead to the replacement module, remove the pillars and install the module into the SART body. Apply a thin film of silicone grease to the new upper ‘O’ ring and fit it into the groove in the top of the SART body. Fit the radome and secure with six screws.

Perform a self-test, a functional test and finally a leak test.



5.4. Re-tune microwave module This procedure should only be attempted by service agents with suitable test equipment. A SART tester, or an accurate, calibrated spectrum analyser is required.

In addition, you will require a cardboard box, tuning tool with 120mm (5") reach, locking varnish and a sealing kit.

This procedure is best carried out in a screened room, because of the need to produce signals for a sufficient length of time to enable correct tuning.

Retuning the SART requires it to be fully operational, but also requires access to the bottom board of the microwave module. The recommended setup is to cut a hole in a cardboard box so that the SART can be held inverted, with the disassembled switch and battery modules lying on the surface of the box. The adjustment potentiometers are accessed through the body of the SART. The upper radome section MUST be in place for accurate frequency measurements. Care must be taken that the box contains no metal or foil, and that any metal objects or surfaces are at least 200mm (8") from the microwave module. The illustration shows a typical arrangement.

Disassemble the SART following the procedure described in section 3.7 steps 1 to 6.



Potentiometers RV101 and RV110 which are used for adjustment can be identified on the underside of the lower board in the microwave module as shown:

Required frequency spectrum

Low = 9.14 to 9.20 GHz High = 9.50 to 9.56 GHz

The frequency spectrum above is provided for the guidance of SBM providers who have access to a spectrum analyser. Users of the SART tester can read high and low values directly as numeric values from the tester screen. Spectrum analyser users need to use a microwave pulse generator set to approximately 9.35GHz to produce a trigger signal for the SART.

The adjustments are interactive, so a process of adjustment is necessary to achieve the exact specified values. Because the SART tester generates the spectrum display by storing multiple samples, adjustments are not always visible during a test. The technique is to use the tester to trigger the SART and to read the values obtained. A small adjustment is then made and the test repeated, and so on until the values are correct. The process is repeated until PASS results are obtained consistently.

When adjustment is complete, apply a drop of locking varnish to the potentiometers.

Reassemble the SART following the instructions in section 3.7 steps 7 to 11.

Perform a self-test, a functional test and finally a leak test.

9.1 9.2 9.3 9.4 9.5 9.6GHz

INITIAL TRIM

FINAL TRIM

3dB

RV101

RV110

RV101 = Centre frequency

RV110 = Frequency spanConnector



5.5. Factory return procedure If a SART cannot be repaired in the field, it should be returned to the factory.

The SART assessment form must be completed and returned with the SART to show the tests which have been performed and the results obtained.



6. SPARES The following items are available as spares: Spares item Part No Contents Battery kits Mk2/Mk3 orange 9V 3way 80-D160

Mk3 yellow 9V 3way 80-D165 Mk3 early 9V 4way 80-D163 Mk2.5 18V 5way 80-D142 Mk1 18V 2way 80-D192 Mk2.5 (Japan) 15V 5way 80-D140 Mk1 (Japan) 18V 2way 80-D194 Replacement parts Mast assembly 80-D139 Mast, L-mounting bracket, 3 screws Lanyard 80-1003B Polytwine bundle with moulded loop Mounting bracket 80-1004B Black plastic bracket c/w labels Test probe (thick) 80-4021 T-shaped probe for Mk1, Mk3 Test probe (thin) 80-4012 Probe for Mk2, Mk2.5, Mk3 (early) Switch guard 80-4011 Black plastic security plug for switch Tamper seal 80-7034 Security label for switch guard User manuals McMurdo RT9 80-7013 McMurdo RT9 (French) 80-7032 Nova RT900 80-7027 Sailor SART 80-7040 Repair parts Upper O-ring 80-8003 O-ring 1.5 x 59mm Middle O-ring 80-8002 O-ring 1.5 x 51mm Lower O-ring 80-8030 O-ring 2.0 x 58mm Upper flange screw 80-8004 M3 x 10mm with 2mm hex drive Lower flange screw 80-8005 M3 x 12mm with 2mm hex drive Indicator PCB 80-8055B PCB complete with cable assy (Mk3) Microwave module 80-8060B Complete module (Mk3)

For older versions of Indicator PCB or Microwave module, call for availability

Battery pack Lower moulding Lower O-ring 80-8030 6 flange screws



APPENDIX 1: SPECIFICATION

Frequency: 9.2 – 9.5 GHz Polarisation: Horizontal Sweep rate: 40MHz / ³s nominal Response signal: 12 sweeps Form of sweep: Forward: 7.5 +1³s Reverse: 0.4 +0.1³s Pulse emission: 100³s nominal EIRP: 400mW minimum (equivalent to +26dBm) Effective receiver sensitivity: Better than –50dBm

(equivalent to 0.1W/m2) (Note 1)

Duration of operation: 96 hours standby followed by 8 hours minimum of

transmission when interrogated with 1kHz PRF Temperature range: Operating:

Storage: -20ºC to +55ºC -30ºC to +65ºC

Recovery time: 10³s max following excitation Effective antenna height: >=1m (Note 2) Delay: 0.5³s max Antenna vertical beamwidth +2dB: +12.5º minimum relative to the horizontal plane of

the transponder Antenna azimuthal beamwidth: Omni directional +2dB Weight: 1kg Dimensions: 300mm long x 62mm diameter

Note 1: Effective receiver sensitivity includes antenna gain Note 2: The effective antenna height applies to equipment

required by Regulation 6.6.2 of Chapter III and 7.1.3 and 8.3.1 of Chapter IV of the 1988 Amendments to the 1974 SOLAS Convention



APPENDIX 2: COMSAR RECOMMENDATIONS These extracts are taken from Guidelines for Shore-based Maintenance of Satellite EPIRBs & Associated Homing Devices, 3rd Draft. 1. Background 1.4 The guidelines should be treated as a minimum level of service appropriate for these devices at

the battery change interval (normally 4 or 5 years) [An intermediate check, for instance at a 2-year interval, is strongly recommended. This should include all tests possible without opening the equipment], and which may be carried out by a suitably trained technician with the appropriate test receiver(s) and general-purpose test equipment. Radiated power and field strength measurements have not been included, as these would require very specialised testing more appropriate at the type approval stage.

2. Shore-based maintenance (SBM) provider 3. The SBM should: 2.2.1 have accreditation to ISO9000 in respect of its servicing operation, or be authorised to carry

out the work by the original equipment manufacturer, Administration or Classification Society; 2.2.2 have access to adequate calibrated test equipment to carry out the SBM in accordance with

these guidelines; 2.2.3 have access to batteries and other spare parts to the original equipment specification; 2.2.4 have access to technical manuals, service bulletins and the latest software versions provided

by the original equipment manufacturer; 2.2.5 keep records of repair and maintenance, available for inspection by the Administration as may

be required. 3.1 Battery change 3.1.1 The main battery should be changed in accordance with the manufacturer’s

recommendations, including the replacement of any other routine service parts (eg seals, desiccants).

3.4 Search and Rescue Radar Transponder (SART) 3.4.1 Great care must be taken to avoid false distress transmissions. 3.4.2 If the SART is a stand-alone device, then the battery should be changed in accordance with

the manufacturer’s recommendations, including the replacement of any other routine service parts (eg seals, desiccants).

3.4.3 The SART should be activated in its standby mode, by switching it on. 3.4.4 Verify that the SART remains in standby mode in the absence of radar pulses. 3.4.5 Apply a low-level X-band radar signal to trigger the SART. This is a check of the receiver

sensitivity of the SART. The test signal may be from a dedicated SART tester, a general-purpose microwave signal generator, or from a modified SART or other radar device.

3.4.6 Check the level and frequency range of the SART response. This may be achieved by a dedicated SART tester, or with a microwave spectrum analyser.

Orolia Ltd Silver Point Airport Service Road Portsmouth PO3 5PB Telephone: + 44 (0)23 9262 3900 Fax: + 44 (0)23 9262 3998 WebSite: www.mcmurdomarine.com An Orolia Group Business 80-7061 Issue 3

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80-7061N Issue 3 RT9 service manual · 2020. 3. 6. · i ENA Telecommunicaciones Respondedor Radar...

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