VHF radio

[Newboy]

I'm gonna get a vhf radio for my boat. The price varies from

[duncan]

A lot of questions! Try looking at it this way possibly......

 

1. Small boat and little shelter makes waterproofing a big factor - generally Hand Helds come out better here (for the money spent)

 

2. Range is a factor of both power and ariel height. However if you are out int eh bay the coastguard will pick up a handheld on their equipement - and you should be able to pick up their transmissions - nav/weather info etc

 

3. With a hand held you are more likely to be able to hear what is being said when you have background noise (it's up against your ear) in my experience. Telephone handsets fitted to a fitted unit are the best but expensive.

 

4. HH performance is often a function of batteries - I would seriously recomend Li-Ion because you can charge regardless of battery state and they just seem to perform better.

 

5. DSC is Digital Selective Calling - you program your ID code (from Offcom with your ships radio licence) into the unit and people can call you direct from their DSC equipement by entering the ID and sending ...... Also it can be linked to your GPS and you simply have to push the distress button for your position to be sent over the airwaves and everyone will know where you have your problem! This is a brief summary - it can do more and has further implications re distress calling etc.

 

6. A US sourced machine is likely to have most, but not all, commonly used channels in the UK but, without a CE mark, it would be illegal to fit such a unit to your boat in the EU.

 

7. You can source very reasonable fixed radios for your budget, although ariels and fittings might take it over, - but I would look to provide reasonable shelter for them. In my view you should look to a waterproof HH with a LI-Ion battery if you go that route and it will probably cost around 220 - I have an Icom MEuro-1V (?)and it is brilliant.

 

I hope you can pick out the answers to your questions from this!

[Maverick Martin]

Hi Newboy

 

In simple terms wattage equates to distance your set will transmit. A hand held unit usually has 1 or 5 watts output. You would select 1 watt for talking to boats that are close to you and 5 watts for all other uses. A fixed unit has settings of 5 watts and 25 watts so you would select 5 watts for talking to boats that are say within 1-2 miles and 25 watts for all other uses. Why bother to change your output you might say, well if your friend is in close proximity to you and you have your set on full power the signal you send out may get blasted pass him and he may not hear you, on low power he will hear you no problem. Also when you transmit others in your area cannot use there radios so using low power for close work allows others to use there sets. Obviously if you are talking to your buddy who is more than a couple of miles away you would select high power. As a rule I leave my set on high power until I need to transmit, I will then either select low power if talking to someone close or leave it on high power for all other work. When I have finished my conversation I switch the set back to high power, the reason for doing this is so that if the radio is needed in an emergency it is already on high power ready to use to call for assistance.

 

DSC is an automated distress calling system. You simply press a red button and your set will send out an outomated digital distress call. If your set is linked to a GPS it will also transmit your position.

 

I would reccomend that you go for a fixed unit on your boat purely because of the power which equates to distance your signal will go. In an emergency the further your signal goes the more people can hear your call.

 

You should be able to get a reasonable VHF for under

[Adam F]

Newboy.

 

We had the same situation last year when kitting out our small 15' dingey.

 

We asked all these questions, and in the end settled on a budget handheld - an XM model from memory costing about 90 quid.

 

Basically it was crap! - The batteries (6xAA) lasted about 5 hours, even when just listening (nb. you use miuch more battery power when transmitting as opposed to monitoring) its range was useless (VHF works on line of sight - if you ariel cannot 'see' the boat you are talking to it wont work - hence the low ariel of a HH, and the mast height of a fixed unit) and it fell overboard!!!!

 

Next we tried a more expensive HH - and ICOM, costing 200 quid. This wasnt much better. It was very waterproof, and the batteries were rechargeable, but still no good for regular use during the day. Would have made a good back-up unit though.

 

Finally we spend 200 quid on an ICOM M104 Euro. It is the most reliable piece of kit on the boat, and it does everything I want from it apart from DSC.

 

My reccomendations to you: 1.) Fixed unit, 2.) Go for DSC.

 

Nowadays you can pick up a cracking unit with all the toys for around 150. XM do one, Silva are about 165. If I was in your boat (xcuse the pun!) I would look at the new Navman model - nice piece of kit.

 

Hope this helps.

[Paul D]

I agree with Adam and Martin. I would get a fixed unit, since the range on handhelds is limited, not by the power but by the height of the aerial ( I do believe I am about to disagree with martin's - wattage = distance note ).

 

Key to VHF range is aerial height and there is no height on a handheld aerial. It is for this reason that an aerial is positioned as high as possible.

 

I too bought an ICOM M401 Euro - doesn't have DSC though, but a superb VHF set, nice loud speaker and dual watch ( even triple watch ) which means you can listen to one channel whilst monitoring the emergency/calling channel 16.

 

Therefore go for big aerial and fixed unit.

 

[Adam F]

The key is power and height.

 

If you dont have enough power the signal will not reach, if you cannot 'see' the ariel, it doesnt matter how much power you have!

 

Ever wondered why when listening to an emergancy call on Ch16 - you can always hear Portland Coastguard - but often not the other vessel? Portland Costguard are loacted some 500ft up on the cliff face!

 

If anyone wants to know more - I have a very basical - but informative book on VHF you are welcome to borrow - handy if you have a VHF, but not yet a licence!

 

Adam

[Bob F]

Yep, both the height of the aerial and the power of the transmitter are the important factors.

 

A VHF signal is "line of sight", so the higher the aerial, the further you will be able to transmit and receive signals.

 

Handhelds are typically limited to around 5 watts for a few reasons, 1) 5 watts uses considerably less power than 25 watts, therefore your battery will last longer, 2) there is little need to have 25 watts on a handheld because the typical aerial height restricts the distance the signal can travel anyway, 3) I wouldn't like the idea of 25watts of VHF signal being blasted into my brain when it's right by my ear.

 

If you have to use a handheld, go for a model where you can plug in an external aerial that is fixed to a high point on your boat.

 

But if your budget allows, and you have sufficient protection from the elements, I'd always go for the fixed unit.

 

DSC is an important consideration. Don't buy a VHF unit unless it has full DSC or is DSC compatible (i.e. you can buy a DSC controller later to upgrade it). Non-DSC VHF's will be virtually obsolete in a few years time when the Coastguard start reducing the monitoring of channel 16. This will not happen for a couple of years yet, but it's worth protecting your investment.

 

You can buy an ICOM DSC compatible unit for around

[Newboy]

If your budget can stretch to

[Maverick Martin]

I think Bob means the 7100

 

Try here:

http://marinestore.co.uk/Merchant2/merchan...tegory_Code=esv