TELL-TALES

Rod Heikell's very informal site on sailing around bits of the world and an eclectic collection of things nautical or nearly so.

 

LONG RANGE OFFSHORE RADIO COMMUNICATIONS

 

Some tips on Single Side Band marine transceivers and Pactor modems from a self-confessed radio nerd.

 

I’ve only been using an SSB for a few years, and not really that much until this last year. I though it might be interesting to pass on some of my new-found knowledge to others joining the twilight world of long range radio communications. Much of what is written below is knowledge gained from experience, much is also gained from a number of kind and helpful experts and professionals, who I list at the end, and to whom I’m extremely grateful.

 

Advice may be found from many sources, but I have sometimes found it difficult to decipher some of the ‘radio speak’ into a language I can understand, at a level which is enough to be useful, but not too much to overwhelm. There are many experienced radio amateurs or HAMS who you’ll meet who will give their time and expertise freely. But beware the ‘expert’ who can really mislead you. How do you tell the difference? Well, maybe after you’ve read this you’ll be in a better position to judge. This is intended as a brief introduction for people thinking of installing a long range radio, or for those who have one but would like to get a bit more out of having it.

WHY SSB MIGHT BE FOR YOU

SSB INSTALLATION TIPS

USING THE SSB & RADIO NETS

DATA FROM YOUR SSB

USING A PACTOR MODEM & TROUBLESHOOTING

THANKS FOR ALL THE FISH AND USEFUL LINKS

 

TOP

 

WHY SSB MIGHT BE FOR YOU

 

  1. To hear voice weather forecasts or to have communications with ships or coastal radio stations for safety or distress purposes when out of VHF range.
  2. To keep in touch with other yachties while on long offshore passages.
  3. To send and receive short emails, send position reports or blogs while on passage with no ‘online’ charges.
  4. To obtain text weather forecasts, weatherfax or Grib files while offshore.

 

WHY IT MIGHT NOT BE FOR YOU

 

  1. If you don’t intend to make many long offshore passages. For the odd long passage a hired satellite phone may be better.
  2. If you want to be able to have high speed internet access, and to send large files and photos while offshore – a state of the art satellite system is the only thing to have this sort of capability.

 

SSB INSTALLATION TIPS

 

Some people will have ‘inherited’ an SSB which is installed on a yacht you have bought. Buying new is a bit of a minefield in the EU, since many radios are not licensed to be sold in the EU, but marine SSB suppliers will have several options. Popular ICOM sets are the M700Pro, M710, M801 and the M802(DSC). These all have email capability as well as all the usual radio facilities. Most people buying new will need some professional help to complete the installation. In addition to the radio you’ll probably have an Antenna Tuner Unit somewhere in the lazarette, linked to an insulated section of the backstay as an antenna, or to a whip antenna.

 

  1. Grounding your SSB system. Our SSB is grounded via the tuner to two dynaplates, via 8AWG wire. (It should really be copper strip, but I couldn’t get any at the time. I’ve since discovered that this is ok for the sort of max power we use – up to 150W – although copper strip is always better). Note our SSB is not grounded independently.
  2. The Antenna. On other boats I often see the cable joining the tuner to the backstay neatly cable tied tightly up against the backstay. It shouldn’t be. You lose loads of transmission power if you do this. You can buy very smart spacers to hold the cable off the backstay, but I made my own using short lengths of polypropylene pipe to do the same job. The cable needs to be held about 6-9cm (3”) off the backstay (or any other big chunks of metal come to that); you’ll need around half a dozen bits of pipe. Drill a hole in one end of each of the pipes and thread the cable up through the holes. Then secure each pipe onto the backstay at suitable intervals using a long cable tie. Loop it around the cable, through the pipe and around the backstay. Secure the end of the cable to the backstay using self-amalgamating tape.
  3. Wiring. Keep the power cable as short as is practical, and if possible take them directly to the battery, and not through the main switch panel. The radio is fused and switched anyway, and is much less likely to suffer or cause interference than if it is wired through the main panel.

TOP

 

USING THE SSB

 

Just like a big VHF? Well no, not really. Users need a Long Range radio licence to operate an SSB. You need a working knowledge of common operating frequencies for ship to ship, ship to shore or shore to ship. You also need to remember that you are often transmitting over a very long distance. Yes, you can use the radio to communicate with fellow yachties, but it is usual to pre-arrange a frequency and a time or schedule for calling each other. Transmitting on SSB demands a high draw from your batteries. SSBs are intolerant of voltages much under 13V, and for most of us this means you need to either run the engine while you transmit, or at least to have fully charged batteries before you start. If you don’t, your transmission will be garbled at best – think of an old 45 record played at 33rpm – and usually unintelligible.

We use the SSB to listen to MF/HF weather forecasts, radio nets and informal nets and scheds with friends. Details of frequencies used for weather forecasts and many nets can be found in Almanacs, Pilot Guides or in ALRS Vol 3 (NP283).

 

 

RADIO NETS

 

Talking to other yachties in harbours and anchorages you’ll find out whether there are any nets running in the area. Some of these are very useful ways of keeping in touch and sharing weather information, like the Westbound Atlantic Cruisers’ Net. This net was set up for the 2007/2008 Atlantic crossing season by a US yacht (and it is almost always an American; they seem to be naturals when it comes to radio nets). Anybody can join, by listening at the pre-arranged time, and following instructions given by the ‘net controller’. This type of net usually follows a pretty standard procedure. The net controller opens the net, giving the time and frequency used, and a brief outline of the purpose of the net. They then invite anyone with emergency traffic to broadcast. There is then often a brief weather forecast, and others may be invited to contribute to this. Then they open the net for any yachts wishing to check in to broadcast their boat name in turn. The net controller will then call each yacht back by name, and requests basic information such as position, number of people on board, last port of call, next port, your wind, wave and weather report and any other useful info. It is a great way of staying in touch with others making an offshore passage, and should you encounter any problems on route, you have an opportunity to let others know what is happening, and whether you might need any assistance. The net will also be alerted if for some reason you do not check in at a later date. If a yacht misses check in then the other nearest boats will be alerted, and they may then be able to try to contact that vessel by other means.

It is normal for the ‘net controller’ to rotate between other yachts in the net, to share this time-consuming task, and  in order to keep the net running after others arrive at their destination. People seem to be reluctant to volunteer for this, but as one who has done it, I can thoroughly recommend it. Yes it’s a bit nerve-racking the first time, but it’s actually fun; you’re taking your turn to help keep it running, and just remember, everyone else is really happy that you are doing it, and wants to help.

TOP

 

DATA FROM YOUR SSB

 

With simple software and a laptop with a sound card you can also receive weatherfax, although I have to admit I never had much success with this, though it works for many.

 

We decided to add a Pactor modem to our set-up to enable us to send and receive small emails while out at sea and out of range of mobile communications. Here are some considerations when setting up this system:

 

  1. You will need a well installed SSB radio with data capability, a windows based computer to run the software, a Pactor modem and lots of cables.
  2. Depending on which radio you have, you may be able to set up the system so that the modem can remotely tune the radio to the necessary frequencies. This makes a huge difference to the ease of use, and if you are buying a new radio for data purposes, then this should be a consideration. Most modern sets do have this capability, but check if you are buying second hand.
  3. Consider the laptop pc you will be using to run the email viewer on. Due to our smallish chart table and its slightly exposed situation, we decided to buy a second-hand tablet pc which is small enough to sit on a shelf, has a shock protected hard drive, and does not store other important stuff on it like documents or photos etc. It cost around £160 on Ebay and runs MS windows 98. It has a serial port and USB ports, and a 12V charger. We also use a USB mouse and keyboard (also from Ebay) instead of the touch-screen controls for ease of use on a bumpy passage. Our main laptop with all our other stuff on it is available as a back up, but we’d rather not use it when underway as the chart table is potentially exposed to rogue douses of seawater slopping around the sprayhood and down the companionway..
  4. SCS Pactor II modem with Pactor III capability is the latest model available. It can come with either serial port or USB connection to your computer. Most modern computers don’t have a serial port, and I chose the USB version as it meant I could easily use it on any laptop if the tablet pc failed for any reason. If you have a serial port Pactor you can get USB convertors, but this gets complicated as they can interfere with the radio. The Pactor III using Sailmail (see below) can send and receive emails up to around 10kb in size. Yup, that’s 10kb; about 2 pages of plain text. Very few attachments can be handled. And you can forget about photos. If you need more than this then you are going to need some sort of satellite communications system, which is not covered here. A SCS Pactor IIusb Modem with Pactor III costs around £650 new.
  5. Consider buying the Pactor from a professional radio supplier – they will be able to help you set the system up, provide all the necessary cables, and will often ensure the system is working properly before you set off. I bought ours from Bob Smith at Sailcom who was able to set up my system and test it using one of his radios – similar to mine – as our yacht was in Greece at the time. He managed to solve an obscure software driver problem that would have stumped me, and thanks to his help, I was able to plug it all in on the boat and get it running with no problems. Of course you may be able to pick up a used ‘bargain’ on Ebay or elsewhere, but there is no guarantee that it will work, and unless you can test it quickly you will have little chance of redress. You will also need to get the fairly specialist cables made up to connect it up to the radio and the laptop.
  6. You will need to sign up to an email provider in order to send and receive email. Sailmail is the best known, with the greatest number of worldwide radio stations, and is the one we use. If you are a radio HAM you also have the option of using Winlink, but you need an amateur radio licence to do so. Annual membership of Sailmail currently costs $250.
  7. You’ll also need to download a messaging program (similar to MS Outlook) – we use Airmail – onto the laptop you will use to connect to the radio. Airmail is designed specifically to work with low speed connections such as radio or satellite phone, and is licensed without charge to the amateur radio community, and to Sailmail subscribers. It is pretty straightforward to use, and has excellent online instructions on the website. Airmail also has excellent facilities to obtain weatherfax, Navtex and US Sitor forecasts, all of which I have used with near perfect results. In addition, part of the email message program has a built-in form for position reporting from Yotreps or Sailblogs. Another great part of the Airmail program is the email-based document-retrieval program Saildocs. Using the Saildocs-friendly part of the Airmail program you can easily request custom Grib files, text weather files or web pages. You can also set up a subscription to receive regular forecasts. This system has a massive advantage over some other similar services as the complex formatted requests are auto-formatted using the Airmail software. It has a simple Grib viewing program. Oh yes, and they even have a propagation program to help you decide which Sailmail station is best for you to connect to at any given place and time. It really couldn’t be easier.  I’m not going to go into the real nitty gritty of Sailmail, Airmail and Saildocs – they have been developed by an amazing dedicated bunch of people with an enormous amount of experience, and they are incredibly generous in sharing a huge amount of knowledge on setting up these systems to work with your equipment. They give advice on choosing a Pactor modem, which radios are compatible, how to improve your grounding system, what cables you’ll need. In short, all I needed to know I found on their websites. I would never presume to propagate their wisdom as my own, although I do try to live my radio life according to the Sailmail Primer!
  8. You can also link your Pactor modem to your GPS so that the Airmail software ‘knows’ where you are. It will automatically fill in your position when sending position reports and will help when selecting an area for Grib files or text weather reports. It also means the propagation program knows where the nearest station is. All you need is a length of speaker wire to run from your modem to the NMEA output of your GPS. (Ours is also linked to the DSC VHF with no problems).

Tablet PC bought on Ebay that can handle everything a steam powered modem will throw at it.

TOP

 

USING A PACTOR MODEM

 

So, you’ve got your shiny new Pactor modem, your laptop with programs downloaded (and backed-up somewhere) a bunch of cables and a compatible radio. You’ve plugged it all together and fixed it all down so it doesn’t all slide around at sea. You’ve joined Sailmail (or another service) and you’ve read all their instructions.

 

Hopefully it has all gone smoothly, you fire it all up and start to use it – and it all works –fantastic isn’t it!

No? Well I’ve seen a few set-ups on other boats where it wasn’t, and I’ve a few tips that I’ve found to help to get things working.

 

 

TROUBLESHOOTING SSB RADIOS & PACTOR MODEM SET-UPS

 

1.  You can hear people, but they can’t hear you?

Check you don’t have any fans running – even less obvious ones such as in the fridge, the engine room, in invertors or even that one blowing gently onto you from above the chart table.

 

2. You can’t select the voice frequency you want to use? 

a.    First, double check it is a valid marine voice frequency for your purpose ie ship to ship or ship to shore.

b.    Some ICOM radios are ‘locked’ as a default. Visit the ICOM website where there is a very useful knowledge base. You will probably find the solution there. It usually involves turning the radio on while holding down a couple of other keys.

 

3.  How do I get started with SSB voice transmissions?

a.    First try tuning in to weather broadcasts from coastal stations. Try Monaco Radio on 8728 or 13146 kHz (ITU Ch 804/1224) at 0930UTC.

b.    Try to arrange an informal sched with another boat. Remember to always check before transmitting for any other traffic, and always sign off with your callsign. Some commonly used frequencies are 8104, 8107, 8122 kHz.

 

4.  You can’t connect to a particular Sailmail station?

a.    Re-read ALL the Sailmail notes.

b.    Check the propagation program to see whether it is a suitable time.

c.     Is it a station with a single transceiver – if so it might be busy on another channel.

 

5.  You hear lots of ‘chirping’ and ‘rasping’ when you are waiting to connect?

It takes a bit of time to get used to which sounds are ‘real’ connections and which are just interference from other stations. Just persevere and you’ll get to recognise which are which.

 

 

 

6.  Your computer locks up and loses connection with the modem when trying to connect to a Sailmail station?

a.    It’s probably caused by stray RF interference. Make sure you have ferrites on all relevant wires. Re-read the Sailmail advice on minimising RF interference.

b.    Try to keep as many wires as possible away from the area around the computer.

c.     Try moving your computer away from the radio – if possible ‘sheltered’ by a bulkhead.

 

TOP

 THANKS FOR ALL THE FISH AND USEFUL LINKS

My thanks to everyone who has helped me to advance my nerd-dom: especially my husband Rod who patiently sails the boat while I’m glued to the radio before emerging triumphantly with a new Grib file or email. Also Bob and Claire Smith at Sailcom, Stuart the marine electrician in Florida and Andy O’Grady.

 

Contacts

YachtCom radio training courses Tel 01489 565100 www.yachtcom.co.uk

Sailcom Marine Communications equipment www.sailcom.co.uk

Sailmail www.sailmail.com

Airmail www.siriuscyber.net

Saildocs www.saildocs.com

ICOM www.icomuk.co.uk or www.icomamerica.com

TOP