Text and photographs copyright of Jim Shead.
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The following is a communication protocol proposed by Mitch Smith
We are looking at trying to put together some uniformity on the PMR446 radio band to enable canal boats to use their PMR446 radio's for universal communication.
We suggest using channel 8, with channel guard slot 8 as the "calling" channel.
If boaters set their radio to this frequency/channel guard while cruising, every-one could contact everyone else.
One would "call" on this channel and as soon as contact was made, change to another channel and channel guard. We could use channel 7, with channel guard 7, as the "talk" channel, just to make it easier when changing.
The idea is to enable boats to call & talk to each other when approaching tunnels/bridges, communicate with friends, communicate with the "trading boats" for coal/gas/wood etc. We could even possibly involve marina's & pubs so you could communicate with them without having to find phone numbers etc.
We are also looking at the newly opened, (as opposed to the old F.M. only) 27 Mhz Citizens Band as this offers far more range. At present though, it still requires a licence, only F.M. and A.M. operation is legal, legal units are expensive and the equipment requires installation of an aerial etc on the boat.
The PMR446 band is hand-held units only and very short range - about a mile at most. It is licence free and the price of units has dropped dramatically over the last few month's - Maplin is selling them at £25.00 a pair at the moment, January 2005.
Channel Guard is officially known as Continues Tone Coded Squelch System, or CTCSS in the trade. There are 38 analogue tones that can be used. Other systems are DCS or Digital Coded Squelch, of which there are 83 Digital codes. Although some radio's claim to have 121 I.E. codes, the first 38 are usually the analogue tones.
Channel Guard is called numerous names by different manufacturers, but they all work the same way. Motorola calls it "Private Line, or P.L.", and lately they have called it "Interference Eliminator or I.E." We have chosen to use the "analogue" slot 8, (88.5 hz for the techie's out there) - so it is not necessary to buy units with the Digital slots available. Also, if you are using the more expensive models, please ensure that the Voice Scrambler function is turned off.
Some of the cheapest radio's have no system at all. These radio's would be able to "hear" the others, but would not be able to talk back. It is essential that you get one with the 38 analogue tones as a minimum.
Hope you join us and look forward to hearing you soon. Best regards - Mitch Smith
Narrow Boat SOMA - Grand Union Paddington Arm, Scrubs Lane/Mitre Bridge.
From: David Robinson [mailto:email@example.com]
Sent: 30 January, 2007 18:49
To: Jim Shead
Subject: Canal Boat Radio
I found your article on Canal Boat Radio very interesting and I thought that your suggestions of frequency standardisation have a lot of merit. I have spent a lot of time on our Canal system with various canal holidays (this year will be our 18th year) and almost from the beginning I have used 2 way radio to keep in touch with my crew so I know only too well the value of CB (and latterly PMR446) radio afloat. I trust that you will not find this E-mail presumptive but I hoped that I could give you a bit of my experience in support of your suggestion.
My experience has shown that both systems have their uses. CB provides dependable long range HF communications of easily 5 miles or more (frequently very much more!) under most conditions whilst I have found that the short range/small size of PMR446 units absolutely perfect for lock wheeling. I would not argue with your suggested choice of CH8-08 as a general calling channel for PMR446 UHF radios and your suggested protocol of calling before entering blind bridges or tunnels makes a lot of sense to me. I have found that PMR446 UHF also works extremely well end-to-end (or should that be portal to portal) in canal tunnels as the short (16 cm) wavelength actually uses the tunnel bore like a wave guide.
The longer (11 Metre) wavelength of 27MHz CB radio has very few problems in climbing out of cuttings and vaulting hills and ridges but it does of course require an aerial to be mounted on the boat. This aerial is easily fitted to most steel narrow boats in a non-intrusive fashion using a magnetic base mount and although a normal CB whip aerial mounted on top of the boat is generally too long to give the air clearance required by tunnels or bridges, there is a short rubber aerial available (the Valor 300, made by Valor/Solarcon) which I have found to do the job superbly well. Being made of conductive rubber (and therefore flexible) it is undamaged if struck by overhanging branches etc. When fitted on a standard magnetic mount, the tip of this aerial stands no more than 40cm above the boat roof on which it is mounted and generally gives ample clearance. Although the range of this short aerial is not as great as that given by a normal CB whip aerial, a communication range of 2 - 4 miles can generally be expected between boats and 6 miles or more from boat to CB base station - in practice this has proved to be more than sufficient.
Due to the recent (Dec 2006) removal by OfCom of the general requirement for a UK CB licence, it means that 27MHz CB radio now falls into the same area of use as PMR446 and I would hope that this means we will see an increasing use of CB radio on the Cut and on our rivers. If this happens I hope that BW will then start monitoring CB radio traffic on a 'standard' frequency - most useful for river locks etc.
In order to keep things simple and in the absence of any formalisation I would propose that Channel 16 should be considered the standard UK CB calling channel for Canal Boats - this conceptually would be in line with the current use of Channel 16 on marine VHF.
I hope that you will find this E-mail of some interest.
Please give Mitch Smith my regards and thank him for raising the subject.
Dave Robinson (2A0FX)