Originally Posted by Jonnymac
Thanks for the speedy reply,
The majority of times I travel no more than one mile out to sea to wakeboard or to fish.
In theory that should be no problem with a handheld. But beware that you wont be 1 mile from wherever the CG mast is. That said it would probably be fine.
However during the summer I had a couple of fantastic trips to the Isle of May from North Berwick and would like to start venturing out more like this.
The Isle of May was approx 10 miles away. Would a handheld radio have the range for this.
Tricky - as seaskills says a lot to do with transmitter aeriel height.
If you have two handheld radios at 1m height and clear sight then their horizon is both 3miles away so *theoretically* they could transmit 6miles. Stand up to get 2m of height and you might get 8miles (if both are stood up). Sitting down (50cm height) and it drops to 4miles.
But thats handheld to handheld. Handheld to a mast will go further...
You say you are travelling 10miles to Isle of May - but unless my geography is wrong Isle of May is to the Northern side of the Forth Estuary. The transmitters on the Forth are located North of the Forth until the Forth Road Bridge (its on the South Side) Since Fifeness Coastgaurd Station (Forth CG) is not far away and has a trasmitter mast I'd expect you would be working that. Can you see its mast on a clear day from North Berwick?
Fifeness mast is about 60m above the ground from the photo I saw. That would mean it can transmit to 0.5m handheld across about 22miles so you should be OK from an aeriel height. As said before - the aeriel height will be much the same for handheld or fixed unit. You may find WAFIs who say different - but they put their aeriel on top of the big stick. if you have an A Frame you might squeeze a few extra miles but the big difference will be from the CG Mast being as high as it is.
You may also want to monitor for port ops. Not sure where they transmit from? (?Leith ?Mast height).
A handheld radio can typically transmit at 1 and 5W, although some now do 6W. If I remember my physics right as the distance doubles from the transmitter the power quarters. A fixed unit will go to 25W which means its transmission will be the same strength as a 5W double the distance away. Most text books claim hand held to handheld of 5miles - so you *should* be able to get handheld to 25W fixed twice that distance (10m) but you might be able to hear and not receive...
SPR hangs round Ellie and may be able to comment what handheld comms are like locally which is fairly close to May.
As for which radio... ...you were brave to ask. 100 people... ...100 answers?
But I hear good things about Standard Horizons and have had good service from Icom. I know people who use Cobra, Silva etc with no issues. Beware the VERY VERY cheap - there is a reason check what its missing (3W max power?, No 37A/M1, No battery life?)
You want waterproof on a RIB (not water resistant). For HH You may want floating or you need to secure it ALL the time. For HH You need battery - Lithium has advantage of less memory issues and better results - I can run my Icom Euro M1 for 2 days on a fairly heavy transmit / receive ratio and still be showing full power (on d3 it will drop). On the other hand if I loose my battery power I am stuffed where most NiMH cells have a battery pack for AAs instead (but they need them as battery life is poorer!). As you have a 12V supply can you find a dry place that would let you charge from a cigarette type socket if your battery is dead and you need to get some juice for an emergency?
Fixed unit - 12V battery is great unless the reason you want the radio is your battery is flat. Added advantage of GMDSS - but if you don't have GPS then its not that useful, although GMDSS is quoted to send digital call up to 70miles.