MF HF GMDSS

There were days when only radio officers operated radio equipments. Deck officers had nothing to do with the radio equipments. With GMDSS equipments all deck officers are radio officers now.

With this new responsibility, came new challenges. Deck officers have since tried their best to fill the gap of radio officer and they have done pretty good.

But there are always few things we never find in book. We call these things “practical experiences”. Many of these were lost with the radio officers but not all.

Deck officers now need to know everything about how to make best use of GMDSS equipment. But GMDSS equipments are of no use, if these wont work when required.

There are many functional requirements of GMDSS equipments. We can only be sure if these will perform or not by testing these at regular interval. Each GMDSS equipment has a testing interval and procedure to test.

Familiarity with the GMDSS equipments is also essential to avoid PSC detentions.

In this post I try to solve this problem with testing of MF/HF equipment and what to do if test fails.

Lets Begin

MF/HF equipment

MF/HF equipment is for sending distress alerts over long range. We need to test MF/HF equipement to be sure of its functionality. Lets see what all test we need to do on MF/HF equipment.

I will show this on JRC equipment MCU-331F. If you have worked on this system, it has a remote mode and local mode. The options to select the tests can be accessed from both modes.

JRC MF HF modes

1. Daily Test

Depending upon the equipment make, we need to do few of the daily tests on MF/HF. Whatever the equipment, the test generally involves

  • checking of internal connections (called Modem Loop test),
  • checking printer and
  • checking display of MF/HF equipment

Besides some makers may have few other daily tests specific to the equipment. Lets see how each of these daily tests are done.

Modem Loop test

What does a successful loop test signify ? If the modem loop test is OK, it means that on receiving a message on MF/HF, it would definitely be processed by the equipment. In other words, it means that received message will not be lost in the loop of the equipment.

In the modem loop test, the equipment send and receives a message internally. If all the loops of the equipment are OK, the message will be transmitted and received without any trouble.

To Perform a Modem loop test on JRC equipment

From Local Mode

Go to Menu#2 -> READOUT & SET UP -> press 4 -> press ENT. This displays the “SELF TEST” screen. Select the “Modem Loop test” and press ENT. Menu#2 is accessed by pressing “Menu” twice.

Modem Loop Test on JRC

From Remote mode

Go to FUNC -> Test -> Modem Loop test and press enter on keyboard.

Modem Loop Test JRC Remote

If the test is successful, OTHERS LED will light up and buzzer will sound. Press STOP to stop the buzzer.

We can then file the print out of the Modem loop test either in separate file or in GMDSS log book.

Printer test 

On receiving a MF/HF message, We tend to look at the print outs than in the screen of the MF/HF equipment. It is convinient to look at the print outs and there is no doubt about that. This makes the printer an important part of the MF/HF equipment. Print outs are also important for record keeping of distress communication. Testing of printer thus is important.

Printer test checks the connection between MF/HF equipment and printer.

To do the printer test, in the Local mode

Go to Menu#2 -> READOUT & SET UP -> press 4 -> press ENT. This displays the “SELF TEST” screen. Select the “printer test” and press ENT.

From the remote mode

Go to System -> Self Check -> Printer and press enter on keyboard

Printer test JRC From remote

If the printer prints all the characters, printer test is pass.

Other Daily tests

As I said earlier, there can be other equipment specific daily tests and vessel should do these test as per Maker’s manual.

2. Weekly tests

Most of us think that weekly test is only DSC test with shore station. We must understand that DSC is only one mode of distress communication. We also need to test our R/T and NBDP every week. Lets see how we should do these weekly tests.

Weekly DSC test with coast station

Every week, we need to test the DSC operation with the coast station.

In Local Mode

  • Go to Menu#1
  • Choose option 11 (Test Call)

Weekly DSC test call

  • Enter the Shore station ID
  • Choose Telecommand -1 as “TEST” by side arrow
  • Choose the Tx/Rx frequency and Press call

If doing this in remote mode

Go to FUNC -> Edit/Send -> Safety test Call and then edit the message if required.

Weekly-DSC-Test-JRC-Remote

On prompt to “transmit the call”, Choose option “yes”.

Sending DSC shore test remote

This will send the DSC test call to shore station. Test will pass if you receive the response back with “EOS” as “ACK BQ”.

It is important that these test calls are not made on 2 MHz frequency and are not made as an “all station” call.

What to do if you do not receive the acknowledgment from shore station ?

Well most of us would agree that this is common situation. And many of us leave it thinking that shore station is not answering. We fail to acknowledge that the problem could be with our equipment.

Some of us believe that filing the test with remarks “No response from shore station” is OK but it is not OK.

Another few has a file with “Typed message” similar to the test with shore response. They just take printout of this message to forge the record to show that the test was done. Whereas actually either it was not done or was done with no response from the shore.

It is very easy to catch if the record was forged or the test was actually done.

So here is how we should proceed in case we do not receive acknowledgment from shore station.

First try again with other stations and on other frequencies. If you are trying to send a DSC call to a nearby station on higher frequency, chance are that they will miss it. This is because, all frequencies has a blind spot near to the transmitter. Higher the frequency, larger is the blind spot distance.

Lets assume that with all your efforts, you still could not get the shore acknowledgment. Next you should try to test the DSC call with a ship station. Testing with ship station is similar to testing with coast station. We just need to change the ID to the ship’s MMSI number of the ship you are testing the DSC with. If possible we should do this ship to ship test on non-distress frequency.

If we still did not get the acknowledgment from the ship, ask the other ship if they received your test call. If they did receive, your transmitter if OK. If they did not receive your test call, expect problem with your transmitter.

Now ask the other ship to send you the test call. See if you can receive her test call. Try it on lower frequencies like 4 MHz. If you do not receive the other ship’s test call, your receiver is not OK.

Now that you know if the problem is with your receiver, transmitter or both, lets troubleshoot it further.

Problem with Transmission

If MF/HF is not transmitting, the JRC manual just ask to call for the service engineer. But there are few other things we can do to avoid this.

1) if you were able to test the DSC with ship but could not test with shore station.

Though this is acceptable sometimes but if your all the last few tests are with ship, it is not acceptable as this can be interpreted as a defect.

In this case transmission of MF/HF is OK, but the transmission power is greatly reduced. This is how you can proceed to solve this problem.

Check the output power setting

On some equipments you can change the power output to low and high. We need to make sure that the output power is set to high for testing. To do so on JRC,

Press Menu on the MF/HF controller -> scroll the dial to go to “Power” option -> set the power to High -> press Enter.

Switching High power on MF HF

Check the Antenna

Even after setting the power to High, still you may not get acknowledgment from shore station. In this case first switch off the MF/HF equipment and clean the transmitting antenna. This Antenna is located on the Monkey island.

MF HF Antenna

The transmitting antenna is connected with the antenna tuner. The connection between antenna and antenna tuner is with a copper wire. In most of the cases you will find this wire to be of green color which is not its original color.

Antenna Tuner wire of MF HF

Remove this wire from all the connections and clean with emery paper to remove the green deposits. Do not put anything (grease, Varnish etc) on the wire after cleaning it. Connect the wire again and test the DSC with shore station. Most cases, you will be able to test with shore station.

Cleaned wire for Antenna tuner

2) If you did not get acknowledgment from ship station as well as shore station

If you were not able to get the acknowledgment from ship as well as shore station, check if the antenna is tuning. Different equipment has different ways to show if the antenna is tuned or not.

Some equipments shows message “Tune Not OK” on the screen. Others like JRC, will have the “TUNE” blinking on the screen. If you see any of these, tune the antenna, by pressing “ANT TUNE” button. If this does not tune your antenna, suspect problem with Antenna tuner.

Antenna tuner is either located in the wheel house or on the monkey island. If the tuner is on money island, and if the sealing of cover is not appropriate, there are chances of burnt PCB. Switch off & isolate the GMDSS station and open the cover of Antenna tuner. Check for any obvious burnt PCB signs.

If there are no visible signs, you need to communicate with maker highlighting the problem of antenna not tuning.

Problem with reception

If you have found the problem with the receiver, you can troubleshoot as follows

The first sign for a poor receiver is no sound on the MF/HF equipment. Tune into any R/T frequency and increase the volume. Do you hear any sounds ?

If you do not hear any sound, try adjusting RF gain.

If you still do not hear anything, MF/HF is not receiving anything.

Another way to know if your receiver is OK is to check the time signal. If you do not receive time signal from any stations, you can assume problem with your MF/HF receiver.

In case of poor receiver, you can check and clean the connection of the reception antenna. The MF/HF reception antenna is usually placed on the forward mast.

If you still do not get anything, most likely the problem lies in one of the PCB of the MF/HF receiver. You should communicate with the maker and if required request for their attendance.

R/T and NBDP weekly Test

Apart from DSC test, we also need to test if our R/T and NBDP are working as these also form part of the MF/HF equipment.

You can test the R/T with a ship station.

To test R/T, Switch to a non-Distress R/T frequency and talk to a passing ship. Follow same with the testing of NBDP. Switch to a non-distress NDBP frequency and communicate with a ship on NBDP.

Monthly Test

Monthly test of MF/HF equipment include the inspection of aerials and insulators. It is important that Electrical officer and 2nd mate check condition of aerials and insulators atleast every month. While checking the condition look for following

  • Any broken aerial or insulator. If any insulator or aerial is broken, order it and replace it.
  • Any salt deposits on the aerial. It is a good practice to clean the aerials with fresh water every month.
  • Connections on the aerial are intact and clean. It is important that all the connection are clean, free of rust and other deposits. If these are not clean, it can reduce the transmission/receiving power of MF/HF drastically. We already discussed one example of this with the wire connecting aerial with the tuner.

Conclusion

MF/HF equipment is a very important part of GMDSS and bridge equipments. If a similar equipment was on board Titanic, it is possible that not a single person would have died.

Keeping this in a perfect shape is the responsibility of ship staff. Testing MF/HF regularly and religiously helps us achieve that. In case of unsuccessful test, we should find the reason for that and correct it.

 

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Capt Rajeev Jassal

About Capt Rajeev Jassal

Capt. Rajeev Jassal has sailed for over 19 years mainly on crude oil, product and chemical tankers. He holds MBA in shipping & Logistics degree from London. He has done extensive research on quantitatively measuring Safety culture onboard and safety climate ashore which he believes is the most important element for safer shipping.

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38 Comments

Kamalakannan
Kamalakannan
May 16, 2016

It's really excellent to guide mariner via blog spot., a great initiative. Want to appreciate all of them who made tis effort. A big salute.

Rajeev Jassal
Rajeev Jassal
May 16, 2016

Thanks for your kind words. We are on a mission to share everything we learnt from our journey of Cadet to Master and Trainee to Chief engineer & beyond. And We are still learning...and so will the seafarers on this journey.. Thanks for being a reader..

Imran
Imran
May 17, 2016

Good Morning sir, I am a fresher cadet and i am trying to make a test call to a Coast Station, but i am not getting acknowlegement. is it ok if i am using 2187.5 khz frequency for making a test call?

Rajeev Jassal
Rajeev Jassal
May 17, 2016

No it is not OK Imran. By doing so you may be blocking an actual distress call of a nearby ship. This frequency is used for transmitting distress call to nearby coast station as well as ships and should never be used for testing. If you are not getting acknowledgment from shore station, follow what I posted in this blog. Let me know if you have any other question now or anytime in your career.

Eugene madjus
Eugene madjus
May 12, 2017

Hi sir Rajeev. So what is the recommended frequencies to be use for sending dsc testcall on shore stations? Thankyou and more power to you..

Amit Rathi
Amit Rathi
May 20, 2016

Bt why you mentioned only 2 Mhz to not to use for weekly testing? Before testing it is required to check the details of the coast stations in ALRS ar ADRS whether they have MF/HF DSC facilities or not. Many stations are equipped with only MF DSC Frequency, for sure we will not receive anything if we try it on some other HF frequency and another important thing is check the rough distance between ship's position and the coast station and choose the frequency accordingly.

Rajeev Jassal
Rajeev Jassal
May 21, 2016

If we are in distress we would not prefer to send the distress call on 16 MHz to an Australian station when we are in Arabian Sea. Our first preference will be a coast station & ship station nearby. So 2MHz is the preferred frequency for distress communication. This is the frequency where if we use for testing or routine communication, we are most likely to hamper an actual distress situation. HF frequency has range upto more than 3000NM so there is no need to use MF frequency when we can easily get a HF station in range. Off course we need to see which HF station is available in range but we need to remove the MF frequency from our list of testing. Hope that clarifies. Let me know if you have any other question Amit.

Amit Rathi
Amit Rathi
May 22, 2016

But what i have been taught is that range depends on the frequency we choose. 4 Mhz covers approx about 400 NM ,8MHz covers approx about 800 NM and so on. And i have observed it too. Not all HF frequency will give 3000 NM range. In west africa I always use capetown for testing and its a HF station . Recently a vetting inspector pointed me out why no acknowledgement ar testing on 2Mhz ...ofcrse i had few with ship stations, so he was ok. But i have seen inspectors asking about 2 Mhz. Regarding hampering the real distress alert , anyway it will keep on repeating every 3 mins until its acknowledged by any station.

Rajeev Jassal
Rajeev Jassal
May 22, 2016

Amit About range you are right. That is why I said upto 3000 NM (16 MHz). And yes distress message will keep on repeating but what if 100 ships are testing on 2MHz. See it is not a requirement as such but is considered best practice. Moreover we should always try to test on higher frequencies because it also tests the transmission power. Let me know if you any question Amit

Mobin
Mobin
Sep 10, 2017

As frequency increases the range decreases.

Amit Rathi
Amit Rathi
May 22, 2016

Thank u very much for the clarification.

Maksood Ahmed
Maksood Ahmed
May 26, 2016

Hats off to u...Got the best clarification for many of my doubts

Rajeev Jassal
Rajeev Jassal
May 26, 2016

Happy that it could clear few of your doubts Maksood. Let me know if you have any question. Hope to see you read future posts too..

Amit Rathi
Amit Rathi
Jun 2, 2016

As I was going through this blog again....a couple of questions rose out again : 1) What if I select ''Individual Call'' instead of ''Test Call'' (There's no Test telecommand in Individual Call) ? 2) When I do the DSC test with a ship station, it will not be possible to do it on a non-distress frequency as all MF/HF equipments are designed to keep watch only on Distress frequencies. 3) When I do DSC test with a vessel , ofcrse the vessel will be a nearer one, within 12 NM circle ar little more....There are high & likely chances that the vessel will miss out the DSC call if I do it on a HF Frequency even 4MHz....so again I have to go back to 2Mhz for testing. Please correct me where ever I am wrong.

Rajeev Jassal
Rajeev Jassal
Jun 2, 2016

1) Individual call is OK, infact some equipments have test option under individual call. As long as you could test the equipment with Individual call, it should be OK. 2) When doing test call with a ship, we usually get in touch with that ship on VHF. And then test the equipment and ask that vessel to acknowledge it.So we should test it on non-distress frequency. 3) You may or may not get the near ship on 4Mhz as the blind spot can depend upon many factors. During distress situations we cannot take any chance so we have to transmit on appropriate frequency but for testing we can try on different frequencies. Like with the ship we can try on 4Mhz to see if they get it otherwise we can try on 2MHz non-distress frequency. In Open sea, with no coast station in range of 2 Mhz, we may test on 2187. Idea is to try not to interfere with any possible distress communication.

Ramprakash
Ramprakash
Jun 15, 2016

Greetings sir I am a fresh cadet I just want to know how to check the chronometer error by using My/Hf equipment

Rajeev Jassal
Rajeev Jassal
Jul 3, 2016

You need to check the time at which a particular station transmits time signal from ALRS and then login on that frequency and wait for the signal to sound. We can then compare chronometer time and the time this signal was supposed to be heard.

MG Gee
MG Gee
Jul 13, 2016

Im wondering what do PSC inspectors in china are refering when the say "No evidence of NDBP test". Can u please show me how to do the test? like u did on top.. thnx a lot..

Rajeev Jassal
Rajeev Jassal
Jul 18, 2016

Many seafarers gets confused with NBDP. Surely a topic to write about. I will write on that soon..

Radoslaw Walczak
Radoslaw Walczak
Sep 21, 2016

Good day First of all great article. But like you said many are confused about NBDP, could you post or send some information how to test it ? Many thanks I have JRC type NBDP

Rajeev Jassal
Rajeev Jassal
Oct 4, 2016

I will write on that shortly Radoslaw..

Radoslaw Walczak
Radoslaw Walczak
Oct 19, 2016

Thanks a lot, I cannot wait, I suppose as the others.

Rav
Rav
Jan 5, 2017

I really enjoy reading your blog capt. Rajeev :) . I can't wait for NBDP issues clarification!

Noman Abdullah
Noman Abdullah
Jul 16, 2016

Excellent writing sir.Keep on writing

Rajeev Jassal
Rajeev Jassal
Jul 18, 2016

Glad you liked it Noman..

Krishnan
Krishnan
Jul 31, 2016

Sir please elobrate on satc testing procedure too

Rajeev Jassal
Rajeev Jassal
Sep 8, 2016

Apart from Daily tests on Sat-C, we need to do weekly performance test and Distress button test..

Capt.Ali Ozcan
Capt.Ali Ozcan
Oct 4, 2016

Great article...

Rajeev Jassal
Rajeev Jassal
Oct 4, 2016

Thanks Capt Ali..

Md sadikul Bari
Md sadikul Bari
Dec 22, 2016

Sir , if possible kindly explain how to do the draft survey in bulk carrier ? .

Rajeev Jassal
Rajeev Jassal
Dec 29, 2016

I will right on draft survey shortly..

Md sadikul Bari
Md sadikul Bari
Dec 22, 2016

During loading & discharging , how to solve the stress problem in bulk carrier ?

Rajeev Jassal
Rajeev Jassal
Dec 29, 2016

I am not an expert of bulk carrier operation but I can write on dealing with stress issues on ships..

Joerg Drexhagen
Joerg Drexhagen
May 11, 2017

And if you want to communicate with another vessel and you don´t know a frequency between the distance and what is the right time for the distance, use the " where & when propagationtool. This windows programs show the right frequency and right time for any distance. This software is proof by the ARC and World ARC. Have a look and test it : https://yachtfunk.com/where-and-when/ best regards Joerg

John pham
John pham
Aug 1, 2017

Gd sir! I need assist from you.MF/HF SRG-1150DN System self test report "received:error,Wach-R:good,Exciter:error,Tuner:good" .so i can not get DSC acknowledgment from ship or shore station.Ask other ship,they received my test call and replied.Please tell me problem detail with it.Thanks you so much.

ZARVAN
ZARVAN
Aug 18, 2017

sir i have been trying out my RT call with other vessel and after pressing the TX button and PTT on the handset....my voice is going through but i am receiving an error: "PA error (32) Module A" & "PA error (33) Module B" & "PA error (31) Detune". kndly help as i am not able to find any info as to what should be the corrective action. Also what frequencies are advised to use for RT call testing.?

Jamokz
Jamokz
Oct 14, 2017

Good day sir, I would like to know how to test two tone alarm of MF/HF Radio for JRC Model JSS-296/596/896 or JSB-196GM R/T ? Thanks.

Smoke
Smoke
Oct 15, 2017

Smoke and mirrors

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