(c) MCA_Orals
Home

Links

This site is run by sponsorship
To sponsor , contact me here

Radar

Radar means Radio Detection and Ranging.

Radar works by putting out microwave radiation pulses and when it hits a target (ship, land etc) it returns to the Radar, the Radar then measures the time, frequency, strength of the pulse and the direction.

When a pulse is transmitted then this is a TX Pulse and when its recieved then this is a RX Pulse.

It is an electromagnetic system that uses RADIO WAVES which travel at the speed of light which is approximately 300,000 kilometers (186,000 miles) per second.

A Pulse is sent out at the speed of light which is 300,000,000 m/s and once it hits a target, the pulse is sent back as an echo, the antenna then picks up the pulse (RX) and delivers it to the receiver as an electronic signal, the signal gets amplified and displayed on the radar screen.


Antenna

The antenna rotates slowly to pick up any targets in your area, it sweeps a 360 degree angle putting out a narrow beam of TX Pulses from the Transmitter (1 degree = 1 Pulse).

The Antenna also receives RX Pulses (echoes from targets) this RX Pulse is put to the Receiver.


Transmitter

The Transmitter puts out a very large burst of energy (a pulse) which last for 0.1 - 5 microseconds and then does nothing until the next pulse is ready to send.

The Transmitter has to send short pulses because it has to be able to receive pulses too, so in reality its listening for pulses more than it is transmitting pulses.

The Transmitter has a switch that switches from TX (Transmitting) to RX (receiving)


Receiver

The antenna recieves an echo and this echo is converted to a frequency of around 30 MHz and then amplified at this frequency and then sent to the computer inside the radar, the computer now converts the analogue signals to digital signals using an analogue to digital convertor and decifiers the information about the target.


Radar Display Unit

The Radar Display Unit is simply a cathode ray tube (CRT), the information from the computer is placed onto the screen by a a sweeping motion going clockwise, when a echo is placed onto the screen a bright spot appears showing you the course and distance from your vessel

(Caution) watch incase your picking up false echoes, rain and sea gain set incorrectly wll cause false echoes to appear on the screen as will a large vessel or high cliffs)
A sailing vessel is a very bad target as most of the vessel is low in the water, recommended to place a radar reflector on every vessel.


Pulse Modulator

The Pulse Modulator delivers power to the transmitter, it has to make the power continious regarding the voltage, power, duration and timing to the transmitter.

The power & voltage to the transmitter should never vary during a pulse.


(WARNING)

Never stand in front of a Radars antenna, the radiation emitted from it can cause sterilization or even cancer.


Oral Exam Tips

Make sure you know what set up you have on your vessels radars

Ships head up, stabilized

North up, stabilized

Know the following too;

(1) Know what scales your radars are set up on

(2) Make sure you know about sea and rain clutter and how to get rid of it

(3) Know how to set up a radar

(4) Range hopping, know how to retune your radar once you've moved the scale

(5) When coming close to land or any target, switch the scale down and re-tune the radar, keep dropping the scale and you'll see the mouth of the harbour opening up.

E.B.L. stands for Electronic bearing line.

V.R.M. stands for a variable range marker.

A large target will affect how good a target is picked up on your radar screen, a very high cliff will give you a good picture on your radar screen, one of the worst targets is a sailing vessel without a radar reflector or a low gradient beach.

During a radar exam you will be asked to set up a radar, screw all the knobs to zero, and switch on the radar, wait till the allotted time has expired and switch the radar on, now turn up the gain so you can see a green/blue screen, tune in till you get the maximum boxes for the strength of the pulses, adjust the rain and sea clutter switches (Important,,,,,, adjust the sea/rain clutter knobs even it its a beautiful day, the examiner will send you out with this if you don't do it)

 

(Q) You'll be asked how to check that the radar is working at its Best
(a) by using the Performance Monitor button (On a radar consol its called "Perf Mon")

(Q) He'll ask you how to check the performance of the radar
(a)

Push the PERF MON button on the consol

Switch it to the 24 miles scale

Press and Hold the T.R. Monitor (This tests the transmission performance)

Use the "Data Wheel" to obtain 4 or Maximum arcs on screen

Release the PERF MON Button

Press the PERF MON Button again this will now check the T.X. Monitor (This checks the receiving performance)

MCA Orals (Certificate of Competency)

Sponsored by
Thomas Gunn navigation services ltd

 

Actual Oral Exams sent from Candidates

Site Map

(C) MCA Orals
Home

Visit The Forums

Last update -24th April 2008 - Photo Gallery of History of Fraserburgh

Check the "Actual Oral Exams" above for important information
(Website sponsored by Thomas Gunn Navigation Services Ltd)
Any View or Opinions expressed are those of the Author and may not be supported by
Thomas Gunn Navigation Services Ltd

O.O.W. /Chief Mates/ Masters / Class 1 & 2 Fishing Skippers M.C.A. Education Website

Introduction

M.C.A. Oral Exam introduction

Website Recommendations

Award Winner

Questions about Rules of the Road


Lifesaving

Liferafts

Launching Liferafts

Contents of a liferaft

Lifejackets

Inflatable lifejackets

Speedline

E.P.I.R.B.

S.A.R.T.'s

Tips of the Day

Search and Rescue


Situations asked during M.C.A. Oral Exam

Various situations

Man Overboard

Flooding Prevention

Bilge Pumping

You've put your vessel aground

Why a vessel can go aground

Collision with another vessel

Marine Pollution

Ways to send a Mayday

Buoys and Buoyage systems

Health & Risk assessment

Ice Accretion

Safe Watch Keeping

Skippers Standing Orders

Entering an Enclose space

Galley Fire

Engine-room fire

Fire in DryDock

Emergency Anchoring

Caught in a Storm

Accidents at sea

Helicopter highline rescue

Red Distress Flare Spotted


Ships Stability

Ships Stability Information

Stability Definitions

Stability Formulas

Stability Sums made easy

Equilibrium

Stability Dangers

Why overfill your vessel?

Calculate Stability Curve


Radar

Radar Plotting Made Easy

Radar Displays

Radar Information

Racon Beacons


M Notices, MGN's, MIN's, MSN's & Statutory Instruments

M.G.N's

M.I.N.'s

M.S.N.'s

Statutory Instruments

MGN 20 - Risk Assessment

MGN 40 - I.S.M. Code

MGN 165- Flooding in fishing vessels

MGN 84 - Safe Watch Keeping

MGN 166 - Passage Planning

MGN 168 - The Marking of Seismic Streamers

MGN 172 - Fishermen'sPilot Book |

MSN 1676 - life saving appliances


Merchant Navy Section

I.S.M. Code (MGN 40)

I.M.D.G. Code (Diesel Oil)

I.M.D.G. Code (Dry Ice)

Rule of thumb for containers

Dangers working with containers

S.O.P.E.P.

S.M.P.E.P.

Grain Work

Dock Water Allowance

Load lines


Chartwork / Compass work / Azimuth Mirror / Passage Planning / Sextant

Chart work

Compass Work

Azimuth Mirror

Passage Planning

Sextant

How to find GMT

Mercator Sum

Polaris Navigation Sum

Sun Azimuth Navigation Sum


Checklists

Deck Checks

Wheelhouse checks

Hanging Block Checks

Deck Machinery Checks

Ships Documentation Checklist

Bilge Pumping checks

Engine Room Checks

Bunkering Checklist

Fire-fighting appliances checklist

Lifesaving Appliances checklist

Stability Checklist

Hanging Block Checklist


Light Recognition (Tips)

Light Recognition

Is the vessel Underway or What?

What is the vessels fog signal?

What is the vessels daytime signal(s)?

What are the arcs of the vessel(s) Lights

What are the dimensions of the vessels light(s)

Light Recognition questions

Pilot Vessels lights questions


Alterations (Tips)

Manoeuvres with vessels in different situations

Alteration Tips

Rule 9 - Narrow Channels

Rule 10 - Traffic Separation Schemes

Rule 13 - Overtaking

Rule 14 - Head on Situations

Rule 15 - Crossing Situations

Rule 19 - Restricted Visibility Situations

Close Quarters Situations

Actions to Avoid Collisions

High Speed Ferries

Wig Aircraft


Photo Gallery

Aberdeen Fishing Vessels (A)

Ayr Fishing Vessels (AR)

Arbroath Fishing Vessels (AH)

Ballantrae fishing Vessels (BA)

Banff Fishing Vessels (BF)

Barrow Fishing Vessels (BW)

Beaumaris Fishing Vessels (BS)

Belfast Fishing Vessels (B)

Berwick on Tweed (BK)

Birds (Sea)

Blyth Fishing Vessels (BH)

Boston Fishing Vessels (BN)

Bridlington Fishing Vessels

Brixham Fishing Vessels (BM)

Buckie Fishing Vessels (BCK)

Campbeltown Fishing Vessels (CN)

Castlebay Fishing Vessels (CY)

Castletown Fishing Vessels (CT)

Cork Fishing Vessels (C)

Colchester Fishing Vessels (CK)

Dacon Scoop Exercise

Dartmouth Fishing Vessels (DH)

Deep Sea Fish

Disaster Photos

Douglas Fishing Vessels (DO)

Drogheda Fishing Vessels (DA)

Dublin Fishing Vessels (D)

Dumfries Fishing Vessels (DS)

Falmouth Fishing Vessels (FH)

Fast Rescue Craft

Faversham Fishing Vessels (F)

Fleetwood Fishing Vessels (FD)

Fraserburgh Fishing Vessels (History of) (FR)

Fraserburgh History (Scenery, Shops, Buildings and People)

Galway Fishing Vessels (G)

Goedereede Fishing Vessels (GO)

Goteborg Fishing Vessels (GG)

Grangemouth Fishing Vessels (GH)

Grimsby Fishing Vessels (GY)

Guernsay Fishing Vessels (GU)

Hamburg Fishing Vessels (HF)

Harlepool (HL)

Helicopters

Helsingor Fishing Vessels (H)

Ice (Bergs and Vessels icing up (Ice Accretion))

Inverness Fishing Vessels (INS)

Kings Lynn Fishing Vessels (LN)

Kirkwall Fishing Vessels (K)

Kirkcaldy Fishing Vessels (KY)

Lancaster Fishing Vessels (LR)

Leith Fishing Vessels (LH)

Lerwick Fishing Vessels (LK)

Lifeboats

Limerick Fishing Vessels (L)

Littlehampton Fishing Vessels (LI)

Liverpool Fishing Vessels (LL)

London Fishing Vessels (LO)

Lowestoft Fishing Vessels (LT)

Merchant Navy Vessels

Mammals

Montrose Fishing vessels (ME)

Newport Fishing Vessels (N)

Newry Fishing Vessels (N)

North Shields Fishing Vessels (SN)

Oban Fishing Vessels (OB)

Padstow Fishing Vessels (PW)

Peel Fishing Vessels (PL)

Penzance Fishing Vessels (PZ)

Peterhead Fishing Vessels (PD)

Plymouth Fishing Vessels (PH)

Portsmouth Fishing Vessels (P)

Sailing Vessels

Scarborough Fishing Vessels (SH)

Scenery at Sea

Shellfish

Skibbereen Fishing Vessels (S)

Sligo Fishing Vessels (SO)

Southampton Fishing Vessels (SU)

St. Ives Fishing Vessels (SS)

Stornoway Fishing Vessels (SY)

Stress of Weather

Sunderland Fishing Vessels (SD)

Tankers (Oil and Bulk Carriers)

Teignmouth Fishing Vessels (TH)

Troon Fishing Vessels (TN)

Tarbert Fishing Vessels (TT)

Urk Fishing Vessels (UK)

Ullapool Fishing Vessels (UL)

Veere Fishing Vessels (VE)

Waterford Fishing Vessels (W)

Wexford Fishing Vessels (WD)

Weymouth Fishing Vessels (WH)

Whitby Fishing Vessels (WY)

Whitehaven Fishing Vessels (WA)

Wick Fishing Vessels (WK)

Yarmouth Fishing Vessels (YH)

Port Letters


Oral Exams and Syllabuses

Oral Exams from Candidates | Merchant Navy Deck Officer Syllabus| Fishing Deck Officer Syllabus

eXTReMe Tracker