Radios

This Post was started by Jon C28 Kindred Spirit C28 and has some edits

VHF Very High Frequency in the marine band. Aerial is about 0.8 Mt (1/4 wavelength) – Calling is Channel 16 (156.8 MHz). Very much the standard with a crisp signal line of sight transmission

27 MHz. Older marine CB type radio typically with an 2.2 metre aerial – Calling freq is 27.88Mhz

HF High Frequency long distance – quite often poor quality but skip off the Ionosphere during sunspots can go around the world Aerial is about 8mt of backstay - Distress is 4125Khz or 6125Khz

DSC.... Digital Selective Calling – An add-on to VHF radio allowing a “one-button” push MAYDAY with a GPS reference BUT VHF-DSC is not monitored in Australia - only HF-DSC is monitored

FROM JON - We need to upgrade the radio and do not have much knowledge as what to buy to meet our needs. Most of our sailing is done on Pittwater with the odd trip down to Sydney. Need some feedback as to what we need to upgrade ....Brand names .Type. and additional set up ..ie...Antenna , Electrics . etc.......What is DSC and do you need to be licenced...And hand helds are they worth looking at..

Look forward to the feedback.......JON

Jon, If you want it around Pittwater with odd trips to Sydney you need VHF. The 27MHz is "club" stuff and it does not go too far. Most boats "out there" will not have it. Range is short. Not worth the hassle. HF is high end. Not for your use. Or mine either at present! Most brands are OK. I use Icom - good unit. GME is good too. They are all pretty good!

Hard wire it into your boat - so generally not "hand held". Having said that, I have a VHF hand-held as well. AND 27Mhz hand helds are great for flexibility and added backup. AND if you fall over the side and think to grab it! Need to keep an eye on them as the batteries discharge over time. I take mine home to "top up" but they charge well on 12 volts too.

Aerial to top of mast gives best coverage. Some have it down low which works but not as far (line of sight). [Maeling with a pushpit mounted aerial got a 5x5 check from Taren Point while transmitting from Lane Cove River.] Personally I have a "spare aerial" too - in case I lose my mast. DSC is great but yes - you DO have to be licenced to get the code from AMSA. Just a course to do with CoastGuard & probably TAFE too. Strictly speaking you should be licenced to use the VHF too but few people are. I am and the course was useful. Electrical wiring should be nice and thick. You are drawing 25 watts or so of power and you want good reliability. Position the unit so you can use it from the cockpit and "down below". I ran wires through the liner space and it's perfect! Hope this helps! Colin – Moonlight Lady C29

Hi Jon,

Replaced an old 27 mhz with a new model back in Oct 2008.

Easily picks up Sydney Radio.

Cost ex whitworths $249.00.

Probably cheaper if shop around \ via www.

Also have VHF on board.

Regards,

Ross.

Ross, Why did you replace your 27mHz? Although I too might do that "just in case" and indeed did have mine repaired. Surely your primary radio is VHF?

Colin

Hi. Colin

Replaced the radio, because - poor reception, lack of range - transmitting and receiving appearance of rust, difficulty in getting service and cost, and replacement resolved all of the above.

Regards,

Ross

From Jon

Thanks Colin ....the old radio is a UNIDEN..27 meg ( I think ) ???? . I can get Sydney Coastal Patrol on it without problem . and would probably keep it for the time being as a back up ...The Antenna is on the masthead can that be used for VHF .....

.Geeez I sound a bit of a ''DILL'' on this one I have never had to use the radio with exception of regular checks with Coastal Patrol Sydney and Broken Bay.

JON the ''OLD SEA DOG ''

Hi Jon,

Anyone can buy and use a 27MHz radio. The licence to own it is automatic, and no extra licence is required to use it.

VHF can be bought by anyone, and the licence to own it is the same automatic class licence as for 27MHz, BUT in the case of VHF you are required to have certification to use it. The minimum is the Marine Radio Operator's VHF Certificate of Proficiency. The exam is a 25 question multiple choice paper that takes about 30 minutes to do. You have to pay to sit the exam and get the certificate (looks like a driving license) but you can study for it by yourself - the handbook for the syllabus can be downloaded from here: http://www.amc.edu.au/omc/handbook

If you are considering doing this, you might as well take the higher level exam for the full MROCP. It's only twice as long and qualifies you for HF radios as well. As the license is for life and can't be upgraded in stages, you may as well do it in one hit.

Lots of people don't bother getting certified, which I think is a poor idea. The Coastal Patrol and Volunteer Coast Guard both hold training days every couple of months, and they are well worth doing just for your own experience. The training day will cover in great detail everything you need to know about marine communications. Training usually costs about $150 but includes all the exam fees etc. Consider the balance a donation to the Coast Guard, who deserve all the support they can get.

As far as coverage goes, both 27MHz and VHF are "line of sight" communications, but VHF is monitored much more than 27MHz by rescue services, and the further you get from large cities the less likely you are to find 27MHz of use. There does also tend to be more "noise" (by which I mean idle chatter and untrained use) on 27MHz. In order to identify your vessel on DSC you need to include an MMSI number which is obtained from the federal government, BUT you have to provide your MROVCP or MROCP license number in order to apply.

DSC is like a paging service, or pre-programmed mobile phone texting. It does not operate on 27MHz, only on designated digital channels on VHF and HF. In the event of an emergency you can send an urgency alert to all stations with a single button press. If hooked up to your chartplotter the alert will include current GPS co-ordinates automatically.

27MHz, VHF and HF radios each require a dedicated antenna. They can't be shared as the antenna length and design is specific to each frequency band. (However you VHF antenna CAN also be used as an AM/FM radio receiver and an AIS transception antenna if you have an appropriate signal splitter installed.

Cheers

Tony

Well, not much to add here!

I would say that I agree that it is well worth while getting the licence. I did it some time ago and it greatly enhanced my confidence in radio and I learned the differences. I learned the phonetic alphabet too which can be very useful in poor transmitting areas. I did the whole MROCP - as Tony says, why not while you're at it?

One thing... While both 27MHz and VHF are line of sight, VHF is far more powerful and will go further. OR maybe that is the perception if repeaters are used (by shore stations). We once sailed down from Port Stephens in company of another vessel who had only 27mHZ and although we were actually further away from Coastguard than the other vessel we had to relay for them (to/from them on 27mHZ and to/from Coastgaurd on VHF. Soon after they too purchased VHF.

For what it's worth you can use the AM/FM radio with your 27mHZ aerial too with the appropriate splitter (Around $50 from Whitworths). We have that setup.

Colin

A late off-line entry from Richard Court Carpe Diem D29

Have you looked at <www.vhfradioonline.com> I found it simple and very helpful? They offer online self study courses for MROCP and MROVCP licences. Also worth noting the Water Police can impose a $220 o-the-spot fine for unlicenced VHF radio use.

Webmasters comment again: My old 27 Mhz still works and I test it sometimes. I’ll pull it out when it no longer works as a backup. Our main radio is a GME VHF beautiful crisp signal from first switch on. We have a pushpit mounted aerial and our test transmission from Lane Cove River was returned from Taren Point – much better than line of sight.

The higher the frequency the shorter the radio wave. The aerial is usually a 1/4 wave long. This is why HF aerials are so long and why the UHF aerial on the Police car is so short. Also when calling Marine Rescue- add what area you are in. It saves them asking so they can designate a working frequency for your call.