|
|
04 January 2012, 00:10
|
#1
|
Member
Country: UK - England
Town: LONDON
Make: SR4/ZODIAC/3D
Length: 4m +
Engine: 30T/40T
Join Date: Oct 2011
Posts: 1,433
|
Handheld radios
I'm re-radioing and given the recent upgrades and power increases am seriously considering a switch from a fixed+hand-held way of life to getting two hand-held devices. There will be 12V charging off secondary battery, obviously.
The idea being that there are a number (4) boats used and if I can take both handhelds onto each vessel every time, that may save me about £5K.
Furthest from coast would be ten miles for two hours. There is an arch on two of the boats.
One main question is, does any manufacturer offer a hook-up to an external aerial from a handheld that is worth it's while? Or is there a way of amplifying handhelds?
__________________
|
|
|
04 January 2012, 01:28
|
#2
|
Member
Country: UK - England
Town: London
Make: Ribcraft
Length: 8m +
Engine: 250hp
Join Date: Jan 2011
Posts: 196
|
sorry I am a bit confused, how would you save £5000 when buying 4 fixed VHF radios (a decent brand i.e. ICOM) would only cost you less than £700?
or am I missing something?!
I have not seen any handheld radio being connected to an external antenna other than its own built it antenna. You can not and should never attempt to amplify the strength of a handhelf VHF radio; two reasons:
1. It is illegal. You are not allowed to transmit over 25W unless you have license.
2. It is dangerous for the user. Handhelf radios are normally operated close to your body so the top of the antenna on the VHF radio has the highest amount of power and it is very harmful if used close to brain. Similar effect of conventional radars on body; more or less, although VHF signals have different wavelength.
Most VHF radios operate between 2-5W, I have seen a 6W model recently, which I think is the max you are allowed as VHF.
__________________
|
|
|
04 January 2012, 07:56
|
#3
|
Member
Country: UK - England
Town: Sussex
Make: RIBTEC 655
Length: 6m +
Engine: Yam 150
Join Date: Oct 2007
Posts: 1,160
|
A decent hand held can be twice the price of a fixed, I have a Standard Horizon DSC HH that outputs 6w and expect I could swap the antenna over but it would really struggle to get anyway near 10 miles, with interrupted light of sight I don't hear Solent Coastguard from Chichester harbour.
__________________
|
|
|
04 January 2012, 09:11
|
#4
|
Member
Country: UK - Channel Islands
Town: jersey
Boat name: Martini II
Make: Arctic 28/FC470
Length: 8m +
Engine: twin 225Opti/50hp 2t
MMSI: 235067688
Join Date: Jun 2005
Posts: 3,030
|
You can hook up a handheld to an external aerial, you just need the right plug on the end or an adaptor, PL259 to BNC for example, depends on the handheld.
You can also get amplifiers that will take you up to 25W.
Agreed though, what's the point? You can buy a decent fixed VHF for £150-200.
|
|
|
04 January 2012, 09:14
|
#5
|
Member
Country: UK - England
Town: York
Boat name: Sugar Free
Make: Tornado
Length: 5m +
Engine: Yam 115
Join Date: Sep 2009
Posts: 119
|
Quote:
Originally Posted by Vandad
2. It is dangerous for the user. Handhelf radios are normally operated close to your body so the top of the antenna on the VHF radio has the highest amount of power and it is very harmful if used close to brain. Similar effect of conventional radars on body; more or less, although VHF signals have different wavelength.
|
Are you sure about that? My understanding is that Marine VHF signals even at fairly high power would not harm anyone. If there is some evidence then It would be worth sharing.
Energy in an electromagnetic wave is proportional to frequency. This is why you can stand next to a 2 meg long wave transmitter without issue, but a few watts of microwave can fry you.
Marine VHF is sort of in the middle.
Gary
__________________
|
|
|
04 January 2012, 09:36
|
#6
|
Member
Country: UK - Channel Islands
Town: jersey
Boat name: Martini II
Make: Arctic 28/FC470
Length: 8m +
Engine: twin 225Opti/50hp 2t
MMSI: 235067688
Join Date: Jun 2005
Posts: 3,030
|
Quote:
Originally Posted by Vandad
You are not allowed to transmit over 25W unless you have license.
|
Quote:
Originally Posted by Vandad
VHF radios operate between 2-5W, I have seen a 6W model recently, which I think is the max you are allowed as VHF.
|
You need a license to transmit at any power level up to 25W. Anything over 25W is illegal, whether you have a license or not.
|
|
|
04 January 2012, 10:41
|
#7
|
RIBnet admin team
Country: UK - England
Town: The wilds of Wiltshire
Boat name: Dominator
Make: SR5.4
Length: 7m +
Engine: Yam 85
MMSI: 235055163
Join Date: Jul 2005
Posts: 13,069
|
Quote:
Originally Posted by martini
You need a license to transmit at any power level up to 25W. Anything over 25W is illegal, whether you have a license or not.
|
Does that mean 6w is just a sensible limit for battery life with a normal duty cycle for handhelds or is part of the limiting factor the small ariels making it impractical to transmit at more than 6w on a handheld?
__________________
Need spares,consoles,consumables,hire,training or even a new boat?
Please click HERE and HERE and support our Trade Members.
Join up as a Trade member or Supporter HERE
|
|
|
04 January 2012, 11:27
|
#8
|
Member
Country: UK - England
Town: LONDON
Make: SR4/ZODIAC/3D
Length: 4m +
Engine: 30T/40T
Join Date: Oct 2011
Posts: 1,433
|
OK, so the idea was to have two handhelds and not four fixed plus one handheld, including fitting and re-aerialing.
Plugging into a fixed, and hence taller, antenna was an idea.
I am licenced.
Don't forget that there is a 12V power supply.
I was kicking this idea around simply because two of the boats are nearly permanently 200 miles apart. The thinking being that having the hardware with me in HH form is handier also from a security perspective.
Some handhelds come with external antenna plugs, thanks MARTINI......do you know which to steer for? I have a preference for ICOM but haven't started tyre kicking yet.
__________________
|
|
|
04 January 2012, 12:13
|
#9
|
Member
Country: UK - England
Town: Norwich, Norfolk
Length: 5m +
Join Date: Apr 2010
Posts: 8
|
I know someone who wanted to do a similar thing with his amateur radio transceiver and he found a cradle which could be connected to a 12v supply and be placed on the back of the radio in the place of the battery. I'm not sure Icom do something similar because I know it says to turn the radio off when charging. maybe it is worth emailing some manufacturers or going to the Boat show and asking there if you can.
You can get connectors for anything on the internet, I've got mini-SMA to PL-259 to connect mine to external aerials. I would suggest a hand mic though because plugging the handheld in can make it awkward to use
__________________
|
|
|
04 January 2012, 15:01
|
#10
|
Member
Country: UK - England
Town: yorkshire
Boat name: little vicky
Make: avon ex RNLI
Length: 3m +
Engine: tohatsu
Join Date: Mar 2008
Posts: 2,310
|
i ran a hand held on a fixed airiel until last year since my base unit was stolen from my fishing boat around 1995,and i never got around to getting another base set ,granted i only ever went out about 6 miles or so using crab pots /long lines .
only thing that i was told by a proffesional radio engineer {guy who repaired and set up ship radios in the local port is that a bit of loss would occour through having an extra unf connecter and extra cable and best not to use it during a thunderstorm .
suppose biggest problem is a lot of newer sets dont have detachable airiels ,
Dont know if the regulations have been changed the maximum power that could legally be used in the uk was for normal marine vhf is or was ,
Hand held /transportable , 5 watts max ,
Fixed base station 25 watts ,
one advantage was the airel was mounted 12 foot up ontop of the wheelhouse/short mast rather than me stood up at 6ft above sealevel ,so i did gain a little .
__________________
|
|
|
04 January 2012, 15:33
|
#11
|
RIBnet admin team
Country: UK - Scotland
Boat name: imposter
Make: FunYak
Length: 3m +
Engine: Tohatsu 30HP
MMSI: 235089819
Join Date: Sep 2005
Posts: 11,632
|
mister p, can you explain your £5k saving figure?
Assuming you already have good cables/aerials in place then a fixed VHF will cost you less than £150 for a respectable unit from a well known brand. (If budget is priority you can buy for just under £100, from less well recognised brands - these may be less suited to the weather onslaught on a rib though). You can spend much more, but there is not really a need to for most users. If the aerials need replacing - the cost will be the same regardless of 25W proper fixed or 5/6W handheld on a fixed aerial.
You can get perfectly reasonably handheld for less than £100, but it won't be all singing all dancing. If you want floating etc - you will pay more. At the very bottom end antennae may not be removable.
Since you are "all legal" I assume you are familiar with the benefits of DSC radio, including touch of a button distress calling - which means anyone can be taught to make a distress call in 5 seconds! Assuming there is already some sort of GPS on board almost any new radio will wire right in very simply and give you DSC benefits. DSC in a handheld will cost you something more like 3x the price of a standard handheld. Beware some really good priced units may not include a 12V charger/craddle to enable you to "wire it in" to the boat, so you will have to pay extra for these.
DSC actually had some other benefits which are skirted over because the red button advantage is so compelling on its own - but group calls, calling the CG without clogging Ch16, being able to position poll a (willing) friend etc - are all useful features; as is the "audible alert" when someone else want to talk to you.
__________________
|
|
|
04 January 2012, 16:07
|
#12
|
Member
Country: UK - England
Town: Dorset & Hants
Boat name: Streaker/Orange
Make: Avon/Ribcraft
Length: 4m +
Engine: 50Yam/25 Mariner
Join Date: Apr 2007
Posts: 5,551
|
As an extra bit of info , I used to fly several aircraft where I used one ICOM HH on a set up with the external aerial & 12v supply. The aerial was just a coax to replace the stubby HH aerial & the 12v supply via a specific ICOM base that the radio clipped into.
No reason why a boat should be differant ( apart form the harsher environment) ?
__________________
|
|
|
04 January 2012, 16:11
|
#13
|
Member
Country: UK - England
Length: 6m +
Join Date: Jan 2011
Posts: 55
|
The type of aerial connector you need at the radio varies with brand. Some take an SMA, others have a proprietary connector, but will supply a "radio to ships aerial connector". This usually gives you a BNC male to which you attach the 'big' aerial.
Don't try to transmit with the aerial disconnected, it can damage the radio.
__________________
|
|
|
04 January 2012, 21:19
|
#14
|
Member
Country: UK - England
Town: LONDON
Make: SR4/ZODIAC/3D
Length: 4m +
Engine: 30T/40T
Join Date: Oct 2011
Posts: 1,433
|
Quote:
Originally Posted by Polwart
mister p, can you explain your £5k saving figure?
Assuming you already have good cables/aerials in place then a fixed VHF will cost you less than £150 for a respectable unit from a well known brand. (If budget is priority you can buy for just under £100, from less well recognised brands - these may be less suited to the weather onslaught on a rib though). You can spend much more, but there is not really a need to for most users. If the aerials need replacing - the cost will be the same regardless of 25W proper fixed or 5/6W handheld on a fixed aerial.
You can get perfectly reasonably handheld for less than £100, but it won't be all singing all dancing. If you want floating etc - you will pay more. At the very bottom end antennae may not be removable.
Since you are "all legal" I assume you are familiar with the benefits of DSC radio, including touch of a button distress calling - which means anyone can be taught to make a distress call in 5 seconds! Assuming there is already some sort of GPS on board almost any new radio will wire right in very simply and give you DSC benefits. DSC in a handheld will cost you something more like 3x the price of a standard handheld. Beware some really good priced units may not include a 12V charger/craddle to enable you to "wire it in" to the boat, so you will have to pay extra for these.
DSC actually had some other benefits which are skirted over because the red button advantage is so compelling on its own - but group calls, calling the CG without clogging Ch16, being able to position poll a (willing) friend etc - are all useful features; as is the "audible alert" when someone else want to talk to you.
|
Polwart, the 5K figure came from a supplier asked to quote for 4 fixed units........supply and fit with rewire and antennae, this included travel to boats and also the price of a handheld.
For me the figure is a bit tongue in cheek and as yet I haven't got the itemised bill as I have no intention in dealing with these people........someone somewhere must have been expecting another Christmas a few hundred days early!
But it got me thinking and I have yet to make my mind up.
DSC has indeed many underlying advantages. I am also one to always want to double-up on safety equipment, so my thinking was that if I was have two handhelds anyway........is there a way to make one punch above it's weight.
But the more I think about it, the more I am inclined to believe that a fixed plus at least one HH is the way forward. Even if the original idea might throw up some Heath Robinson inventive corner-cutting.
The right gear is already out there (from the right supplier).
So I reckon on four M411 and a couple of M71's. I want to stay with ICOM.
There, decision made. Earlier than I had predicted!
__________________
|
|
|
04 January 2012, 21:27
|
#15
|
Member
Country: UK - N Ireland
Town: Rostrevor
Boat name: Ricochet
Make: Redbay
Length: 7m +
Engine: Twin F115 Yams
MMSI: 235083269
Join Date: Oct 2011
Posts: 930
|
Quote:
Originally Posted by mister p
So I reckon on four M411 and a couple of M71's. I want to stay with ICOM.
There, decision made. Earlier than I had predicted!
|
Good decision
__________________
Maximum Preparation - Maximum Fun
|
|
|
04 January 2012, 21:36
|
#16
|
Member
Country: UK - England
Town: Up Norf
Make: Avon SR4,Tremlett 23
Length: 4m +
Engine: Yam 55, Volvo 200
Join Date: Apr 2007
Posts: 5,217
|
Quote:
Originally Posted by Vandad
2. It is dangerous for the user. Handhelf radios are normally operated close to your body so the top of the antenna on the VHF radio has the highest amount of power and it is very harmful if used close to brain. Similar effect of conventional radars on body; more or less, although VHF signals have different wavelength.
|
Who told you this as it sounds like bollocks to me.
A radar is transmitting all the time it is turned on, even IF a VHF did cause a health hazard it would only do this when it is transmitting.
__________________
|
|
|
04 January 2012, 21:44
|
#17
|
Member
Country: UK - Scotland
Town: Central Belt of Scotland
Boat name: Puddleduck III
Make: Bombard
Length: 5m +
Engine: 50 HP
Join Date: Mar 2009
Posts: 2,066
|
the new icom range will be announced at London boat show....I believe a DSC handheld radio
A bit of googling will find the specs, since icom France have published it in their website!
S.
S.
__________________
SPRmarine / SPRtraining
RYA Training Courses & Safety Equipment Sales
|
|
|
04 January 2012, 21:51
|
#18
|
Member
Country: UK - England
Town: England
Boat name: n/a
Make: n/a
Length: no boat
Engine: n/a
Join Date: Jul 2009
Posts: 368
|
My fixed antenna is on the console. Is this slowly frying my brain?
__________________
|
|
|
04 January 2012, 21:53
|
#19
|
Member
Country: USA
Town: Seattle
Boat name: Water Dog
Make: Polaris
Length: 4m +
Engine: Yamaha 60hp
Join Date: Apr 2007
Posts: 1,152
|
Quote:
Originally Posted by maxhar
My fixed antenna is on the console. Is this slowly frying my brain?
|
Yes, did you expect to live forever?
__________________
|
|
|
04 January 2012, 21:53
|
#20
|
Member
Country: UK - Scotland
Town: Central Belt of Scotland
Boat name: Puddleduck III
Make: Bombard
Length: 5m +
Engine: 50 HP
Join Date: Mar 2009
Posts: 2,066
|
Quote:
Originally Posted by maxhar
My fixed antenna is on the console. Is this slowly frying my brain?
|
yes - and that mobile phone you use, x-rays and microwaves are not helping much either....
not forgetting the Wi-Fi and Cordless phone waves....
hence I wear a tin foil hat!
S.
__________________
SPRmarine / SPRtraining
RYA Training Courses & Safety Equipment Sales
|
|
|
|
|
Posting Rules
|
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts
HTML code is Off
|
|
|
|
Recent Discussions |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|