Handheld VHF Marine Radio

[Richard Mason]

Well, I 've just got my new inflatable , divers for the use of, set up.

I'm looking at getting a VHF radio, something like this, although not necessarily this model. I won't have a big battery on board the boat, nor a charger in the motor, so the conventional wired in job isn't an option.

It seems that these things will only have about 5kms range at full power, and given the waters I inhabit and the small numbers of boats around, I'd like to improve this so I can reach more boats and the coastal repeater stations etc, so I was mulling over the idea of fitting a folding antenna to the transom of the boat, with the capability to plug this in to the handheld, if required.

Does anyone know of any models of handheld marine radio that provide for an auxilliary antenna input capability?

[Hazel W]

Icom used to do a model that you could replace the whip ant with a bigger one ...dunno if they still do


H

[NeilB]

Correct me if I am wrong (probably are) but......

Increasing the height of the antenna only helps a little bit. The wired in sets transmit at a higher power thus have a longer range. Handheld jobbies transmit at a lower power and thus the size of the antenna is largely imaterial.

[Twinsetmad]

A mate of mine broke to antenna of his rib under the peir at Anglesea a few weeks back....his replacement antenna is shorter than the one on my handheld....its only about 4 inches high...

I think its more to do with the power out than the size of the antenna.

[Adrian Kelland]

Originally Posted by NeilB

Correct me if I am wrong (probably are) but......

Increasing the height of the antenna only helps a little bit. The wired in sets transmit at a higher power thus have a longer range. Handheld jobbies transmit at a lower power and thus the size of the antenna is largely imaterial.

I seem to recall that height of transmission point does matter as the system is essentially line of sight. Else the CG would not have tall masts on the tops of cliffs where possible.

Wired sets tend to have a power rating switch - low power is usually enough as a CG area has several masts.

Adrian

[Phil Laughton]

Most hand held radios have two power settings, one and five watt transmitting power. Fixed transceivers with DSC can have twenty five watt transmitting power. An arial fitted as high as possible will allow the signal to travel beyond the visible horizon and be picked up by an equally high mast on an earth / MCG station.
To get the best from your radio join a training course to obtain your operators short range cerificate, a legal requirement to operate any radio without supervision.

Phil

[stevechesh]

just to add. . .

You can also alter the range of radio transmitters, by simply changing the angle you hold the transmitter/receiver and the aerial.

I seem to recall in my radio/radar training years ago, something to do with dipole effect. However, it is also weather/atmospheric condition dependant. . . .

[Richard Mason]

Originally Posted by stevechesh

just to add. . .

You can also alter the range of radio transmitters, by simply changing the angle you hold the transmitter/receiver and the aerial.

I seem to recall in my radio/radar training years ago, something to do with dipole effect. However, it is also weather/atmospheric condition dependant. . . .

Yeah but that's HF, VHF is line of site, the HF stuff gives you differing ranges etc dependent on the condition of the ionosphere. We used Raven HF sets when I was in sig platoon too. (ok so I was a shirtlifter) and did a lot of that stuff but I don't think it applies so much to modern vhf antenna.

The difference in military use is that you are often trying to minimise range of radiation emissions and making it asa directional as possible to avoid unauthorised eavesdropping. With this, I want everyman and his dog within bulls roar to hear me and hoping to make bulls roar as big an area as possible.

I've transmitted for a couple of clicks or so from an ANPRC 77 vhf set using an ordinary pencil as an expedient antenna, buton water, you need to get the tip of the antenna as high as possible to maximise surface wave effect. I can imagine losing a lot of the signal just from the swell if reliant on the hand held radio built in antenna.

My best transmission on the HF Raven was on a trip up north to an Exercise near Alice Springs from Adelaide, in a FFR Landrover, We'd just got the Ravens and had done a bit of work on expedient antennas and wanted to see what it'd do, so I hung a piece of DOM10 K-Phone wire out of the antenna socket and attached it to the chainlink mesh fence around the local football ground, cranked up the power and managed to talk to a bloke in Papua New Guinea. Only trouble is, it probably gave the Indonesians a good idea of what they'd do too. Now that's what I call an antenna.

[Richard Mason]

Originally Posted by Phil Laughton

To get the best from your radio join a training course to obtain your operators short range cerificate, a legal requirement to operate any radio without supervision.

It isn't if you don't get caught.

There's actually not that much to remember; mainly don't use 16 for anything other than establishing comms, don't use 16 on the hour and half hour, don't turn a radio on unless the antenna is connected and the difference between Pan and Mayday.

[Rookie]

Originally Posted by Richard Mason

It isn't if you don't get caught.

There's actually not that much to remember; mainly don't use 16 for anything other than establishing comms, don't use 16 on the hour and half hour, don't turn a radio on unless the antenna is connected and the difference between Pan and Mayday.

I believe you are legally alowed to have a hendheld radio on a boat, without a licenced operator, as long as it is only used for monitoring or Emergency transmissions. You just can't chat on it. I can't see somone putting out a valid distress call, then being prosicuted for not having a radio licence.

Phil