SSB/HF Transievers etc (Again)

Dougal

Dougal

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I have seen the other SSB thread, but I have some other, perhaps more general questions if you can help?

After many years of coastal sailing in various parts of the world, we’ve decided to try a longer cruise…..

In 2008 we’re planning to sail from Southern Brittany to the Azores, with an open option to continue West for a year or three if we enjoy it.

We’ve read many books by long term cruisers etc, most of which seem to carry long range transceivers. None of these however, supply the logistical and technical info I’m after…..

The only licence I currently hold (apart from VHF ships licence), is the restricted VHF certificate. I know VERY little about all the other maritime frequencies. Errr…. SSB… I think: single side band?, though no bleedin idea what that IS. HF – high frequency, is it still used? And, good old shortwave – we’ve all heard of it I’m sure, but to be honest, I don’t really understand the differences between any of them.

I’ve had much conflicting ‘advice’ about what I should, and shouldn’t have on board. Some say the antenna can simply be run up the backstay, others have said any radio should have its own mast mounted antenna. I’m sooooooooooo confused.

Any general or specific info/advice would be much appreciated, even it’s just a pointer in the right direction.

Many thanks
 
They are talking about HF(SSB) HF = High Hrequency SSB = method of modifying the frequency to include the information.

There are two possible licences - Marine long range dsc certificate (actually about as relevant as HGV certificate for boating!) or the radio amateur (HAM). Theoretically you cant use the same equipment to operate on both marine frequencies and Ham frequencies. and a HAM wont speak to a marine only certified person. (not actually legally allowed to!) However you only need these licences if you intend to transmit, they are not necessary for receive only.

HF(SSB) is used for several different things:

long distance emergency - this was original purpose, but these days most of the shore stations have shut down. Some have DSC watch - but most cruisers dont have modern DSC capable HF.

Maritime chat circuit - major reason for Transmit capability today.

Weather fax and navtex receipt - very useful to get the eather and download to pc. You do not need a license for a receiver that will do this.

Email - You would need a very expensive Pactor modem, and it is very slow. Might just as well use an iridium phone for this.
 
Just to start the discussion, as I'm sure I'll say things not sufficiently precise on the technical side and many a forumite will like to be perfectly precise. /forums/images/graemlins/blush.gif
SO:
High Frequency now is SSB (Single Side Band, an Upper Side and a Lower Band): tranceivers adjust by themselves to USB (NO LIN TO PC USB PORT) or LSB.
They have a double type of connection: a line of sight (just as VHF) which is around 35 N.miles and a far broader range due to reflection of radio waves by the ionosphere; in this case you may expect a 2.000 miles radius (yes, twothousand) as the signals travels from the aerial to the ionosphere and then back to earth (or sea): the range depends on the situation of the ionosphere, which is very variable (you can find maps on the net with the expected range at a give date/hour/place).
This tranceivers are usally arond 150 watt, are included in the GMDSS system (so you can program your MMSI code, just as you have in the VJHF) and require a specific license. 400 watts radios are available.
There are some private networks which allow you to transmit and receive, typically using a Pactor modem, e-mails at a cost of around 250 euros a year at max 9600 bauds (remember those long forgone times?).
With the same radio you can get Navtex and Meteofax messages and weather charts. Aerial is typical obtained by isolating a long portion of backstay.
By the way I just read an article by Motorola saying that a long HORIZONTAL aerial is the best way to send radio waves in the ionosphere; i don't know if it is erious or just Marketing Hype
An alternative is satellite telcom, which does not require a license, has high cost of usage, and a coverage depending on the system You are using (Thuraya, ecc.).You can of course send and receive mails with sat com but expect even a lower speed (4800 baud). Aerial is tipically in the telephone set, so you have to use it in the cockpit or buy a special set with an exit for external antenna.

Other systems include Thrane, KVH ecc which, IMHO, are cumbersone and expensive on a less than 20 meters boat.

/forums/images/graemlins/cool.gifDepending on your willingness to pass exams, /forums/images/graemlins/mad.gifI would stick to HF SSB plus Pactor modem; if too lazy to do some studying, go satellite. /forums/images/graemlins/crazy.gif
 
My best advice would be to contact your nearest HAM radio club and see if they run courses. Although you might never want to transmit on the amateur bands the course teaches you most things about operating the radio, setting up an antenna and what makes it all work.
Few cruisers hold the official SSB operating qualifications but do keep to the rules when transmitting. The big advantage of SSB is its range but this also means that anyone transmitting incorrectly can affect a much larger area (most of the world) and more people than with a VHF transmission.
There are very strict rules - for instance, it is illegal in most countries to transmit within their territorial waters apart from contacting coast radio stations (few and far between now), port authorities and for emergencies. The frequencies used are also strictly regulated.
I have an amateur SSB, modified for use on all frequencies. I also hold a full amateur license but have only used the radio to talk to other cruisers on the marine bands.
IMHO you should definitely get some formal training before using an SSB.
Good luck,
Henry
 
Oowerr missus.... my head hurts already /forums/images/graemlins/confused.gif /forums/images/graemlins/confused.gif /forums/images/graemlins/confused.gif

Some serious info to be going on there - thanks guys
 
Quote "By the way I just read an article by Motorola saying that a long HORIZONTAL aerial is the best way to send radio waves in the ionosphere; i don't know if it is erious or just Marketing Hype" endQuote

In the good old days of ships having MF/HF transmitters normal practice was to string the copper aerials horizontally.
 
[ QUOTE ]
Quote "By the way I just read an article by Motorola saying that a long HORIZONTAL aerial is the best way to send radio waves in the ionosphere; i don't know if it is erious or just Marketing Hype" endQuote

In the good old days of ships having MF/HF transmitters normal practice was to string the copper aerials horizontally.

[/ QUOTE ]

This is the link:

http://www.royal-communications.com/pages/hfssb_today.html

Cheers
 
Dougal,
Excuse me if I have misunderstood your posting and am replying at too basic a level.
VHF, with which you are familiar, is a means of voice-communicating over relatively short distances with other ships, or with the shore. Typically you are communicating up to about 25 miles. You can listen and you can talk. You buy a set, attach it to a whip antenna at the top of your mast and you are in business. You can also have a hand held VHF radio which provides portability but shorter range. VHF range is “line of sight” so an antenna located higher up is better than one at deck level.
SSB is a means of communicating with ship or shore over much longer distances – up to 6000 miles in some cases. You buy a set and connect it to an antenna system and you are in business. The antenna system is more complicated than VHF and is not interchangeable with it. You will typically have an automatic antenna tuner into which the radio set connects and then that feeds an antenna which is typically your backstay, or a wire running up your backstay, insulated top and bottom. You will need a ground plane, usually provided by bonding all the heavy metal bits on your boat together and laying copper foil strips hither and thither. So, more complicated in terms of hardware and installation but allows communication over long distances.You can choose to just listen or you can transmit as well. With SSB you can listen to weather and other security information being discussed by boats in your vicinity, or quite far away. Ham radio is similar to SSB and some use it in place of SSB. Licensing requirements vary and should be researched for your particular administrative area.
Short wave radio is typically a radio receiver on which you can receive, for instance, BBC World Service. It is more an entertainment and informative thing than a communication medium.
Beyond these forms of communication you have cell phone, not really much use off shore, and satellite communications – basically an expensive to use phone system.

I hope this helps.
 
"Long horizontal aerials are the best"? .....er NO.

All transmitting antennas can be described as having a vertical or horizontal component. Therefore a vertical antenna (ie a vertical pole) radiates predominantly vertically polarized radio waves and a long horizontal wire radiates predominantly horizontal polarized radio waves. A sloping wire radiates both components.

Both can work very well or very poorly dependent on frequency, length of antenna and height of instalation. For a horizonal antenna you need to mount it at least 1/4 wavelength high and better still at least half a wave length to get good propagation. That is a real problem at 1.8Mhz ie 40m high - so most people choose a vertical which can be mounted at ground level (with a good ground). A low horizontal can still work but a lot of the propagation goes straight up.

To do this justice, I could write a book on it, as many have done so it would just bore the pants of everyone...so I'll give up now

Fully agree with Henry - you need to read up on the use of an SSB transmitter. You can interfeer with radio stations half way round the world with a 100W at sun spot peaks if you dont know how to set a station up or operate it.

...by the way, anyone one point me to a site that gives me some info on "snipping" a ham radio to transmit in the marine bands - particularly the newer radios from Kenwood that might have a software key rather than snip a diode.

Dr Bob
 
Radio waves are (ignoring quantum mechanics) ............... waves. The distance between the peaks of the waves is the wavelength - hence medium wave (say 200 metres) long wave (say 1500 metres ) and short wave ( say anywhere from 40 metres downwards). These waves travel at the same speed (the speed of light) so the number of cyles that pass any point in one second is speed light divided by wavelength. Thus HF radio which is shortwave is maybe 5 million cyles per sec up to 50 million cycles per sec. Very high frequency is more than this - say 100 million cyles per sec or 2 metres wavelength.

Why does all this matter? Well in the case of aerials and particularly those used for tranmitting, the length of the aerial has to bear some relationship to the wavelength of the radio signal. Typically you work in multiples of a quarter wavelength - any less than this and the leccy doesnt escape the aerial and ends up frying the output stage of the transmitter. OK this is a sweeping generalisation but dont expect a 3 foot length of wire to work as a transmitting aerial on the maritime mobile nets, though it may well work on the VHF radio.

Thats why people use the backstay for the SSB aerial. On my last boat the backstay with the help of an aerial tuning unit ( a black box often just called an ATU) would work OK on ham bands from 40m upwards but wouldnt work worth a damn below that. And incidentally, an aerial wire attached via insulators to a halyard and hoisted when you need it is a far cheaper and less risky alternative than putting insulators into the backstay.

Turning to the practical side of what use can you expect from an SSB? Well its OK for chatting on the occasion when you are (say) 30 miles from land and the VHF / mobile dont work, but nearer land than that the alternatives are much better. Indeed, with a minimum 40m signal, SSB works in line of sight and then at various skip distances depending on time of day, when it does up to the atmosphere and reflects down again. This is why the NASA weahterman has a choice of wavelengths on which to receive the weather signals. At various times of day, some frequencies work and others dont.

Weahter info on SSB is poorer than yoiu are used to on VHF unless you log into the ham nets or nets like Herb. For the ham nets you need a license.

I could go on for ages about the technicalities but to save my typing finger, all I would say is that as a radio ham and with all the necessary kit I would take a satphone every time both for weather, e mail, for safety and for general chatting. HF radio is an interesting hobby but as a tool it has IMHO gone the way of the telegram.

Safety is a particular issue. Monitoring of the SSB emergency frequencies is dropping off as more sat phones are used. Propagation issues also make reception less reliable. You need a specialist marine set to get DSC and wake up the dopey watch on board ships. All in all, a sat phone is a better bet. Or an epirb, or both etc.
 
Actually its all quite simple... Once you leave European waters almost all cruisers keep in contact with each other via SSB.. lots of chat, local info and if you get into trouble then they will rally round.

With either a Marine SSB set or a ham set you need a good antenna and the easiest way to install that is by placing a couple of insulators in your back stay. You also need a ground plate - either your keel or a proper ground plate. Much like an anode - two bolts in the hull - but a bit more expensive.

The tx/receive set can be a ham or marine SSB set which either way needs 'sniping - adjusting so that it will transmit on both sides of the band - marine SSB and Ham - just for safety.. the hams will help if you are in trouble even if you do not have a ham licence.

There is a lot of 'stuff' about licences which is all out of date and no longer relevant which grew from the Titanic disaster. Nowadays most big ship safety traffic is carried out on Sat telephone and the majority of big ships do not carry a radio operator and certainly do not use SSB to communicate.
t
You simply fit the set - fix the antenna and tuner and off you go.. Quite un-necessary to bother with licences or all the other bumph,, few real cruising folks do bother.. The American authorities have a very laid back attitude to it all.

In fact email by pactor modem is about $250 US a year unlimited and the cost of a Pactor modem around £400.. Unless you are an Internet/telephone/email addict it is the way to go all over the world...

Cruising folks use SSB to chat on, to get weather on, to get info on and if the sh*t hits the fan to get help on...

Forget the theoretical rules and regulations, nowadays in the real world it is the main communication method of long distance cruisers between each other and unused by most other folks. If you find it interesting for technical reasons then becoming a ham appears to be a very rewarding and satisfying hobby.

Michael
 
If you are going to the Azores, a Globalstar sat phone is worth serious consideration as they are not majorly expensive to buy (easily picked up on eBay for £300). reasonable to use (0.70 euros per minute) and have 9.6kbps data speed, so very useful for weather and emails, especially with the excellent software form www.ocens.com. A whole lot cheaper than buying, fitting and getting licensed for an SSB transceiver, as well as being much more convenient. Plus easily sold after your trip - without leaving holes in your boat!

All that being said, I did find Herb - a guy who voluntarily provides first class weather routing for north Atlantic sailors - a great asset when I did the trip.
 
Dougal
I have plans to go long distance sailing in the near future. I have just done the Long Range Certificate training at yachtcom.co.uk near Hamble run by Bob Smith. Took 3 and a half days with exam, but covered many of the points made here and well worth it. Course covered VHF SSB Sat communication EPIRBs and SART. I came away with a lot more knowledge and a certificate! Also we were able to chat about sailing etc during the course.
I have no connection with yachtcom other than a satisfied customer. Look at the website.
Brian
 
Near Vertical Incidence Antenna Systems (NVIS)?
An earlier post mentioned that a horizontal need to be at least a 1/4 wave length up in the air. Well if it isn't you get a NVIS and your signal goes straight up and sometimes back down just a few miles from where you are. Great if you are the other side of a mountain to the people you want to communicate with. The armed forces use this (or did)but it's not really useful for long range communication at sea.
see www.dkmods.com for info on how modify a ham radio.

Guy
 
The whole scene is changing rapidly. You can get some ideas about the technology from the library books but as to what is best to use ie HF SSB , Ham ,Sat phone etc can change almost by the month. And it varies from area to area. If you were a radio enthusiast you might have SSB maritime frequencies and Ham licences and facilities but I suspect that satelite is the way it is all going. Just keep asking arounnd people who have recently done the voyaging or who are in the middle of a voyage.

Certainly HF SSB is not a system where you pick up the microphone and talk like VHF but takes patience and skill to adjust the set and select the right frequency for the conditions and range

Regarding antennas I believe around here that a HF SSB antenna which relies on mast integrity will not meet the requirement for HF SSB maritime frequencies required for ocean racing. The antenna which willl meet the requirements is a helical wound vertical whip around 4 metres long mounted on the transom. Thhat doesn't mean a backstay is not the best but that loss of mast is a common distress mode. Merry christmas to all from olewill
 
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