Uniden MHS050 ok for 2km offshore?

BoatFisho

Petty Officer 1st Class
Joined
Oct 12, 2013
Messages
249
We never venture further than that in our boat, it has switchable 1w to 2.5w, is that enough to reach 2km?

It suits our limited budget and is waterproof and supposedly floats.
 

Bob_VT

Moderator & Unofficial iBoats Historian
Staff member
Joined
May 19, 2001
Messages
26,084
Yes .21/2 watts is plenty of power for 2 KM provided you are holding it upright. The antenna must be verticle...... you should not hold it sideways to talk like some people do with cell phones.

The other biggest complaint I have with ANY radio (Yes I am a lisenced amature radio operator too) is the volume from a tiny speaker. If you have a motor running or are underway you will find it VERY hard to hear. The older I get the worse it is for me but even younger people have complained about volume.
 

BoatFisho

Petty Officer 1st Class
Joined
Oct 12, 2013
Messages
249
thanks. what do you think the maximum range of 2.5w would be out of interest. where we boat there are always at least 8 boats within site, sometimes 30 lol.
 

Bob_VT

Moderator & Unofficial iBoats Historian
Staff member
Joined
May 19, 2001
Messages
26,084
The key to proper radio distance is the antenna. I would strongly suggest that you seek out a Ham radio operator and ash them for set up assistance with a good antenna for marine bands. The 2.5 watt with a proper antenna will out perform a larger wattage radio that is not set up right.
 

jhebert

Ensign
Joined
Jul 24, 2005
Messages
903
If you are in the USA, you are most likely operating your boat in a coastal region of the USA that is covered by the Coast Guard RESCUE 21 radio system. The RESCUE 21 radio system was designed with a MINIMUM performance goal of communicating by VOICE and by DSC with a 1-Watt VHF radio that is six feet above the water to a range of 20-miles offshore. This coverage is provided in 98-percent of the shoreline.

On the basis of RESCUE 21 coverage and performance, it should be possible for you to very reliably communicate with the Coast Guard using a 2.5-Watt VHF radio held at six-feet above the water at a distance of 1.3-miles (2-km) offshore.

Exactly how far you can communicate with other stations is impossible to know. The reliability of any radio path is determined by the capabilities of both stations. The distance you can communicate with other stations will depend on the capabilities of those stations. The capabilities of the Coast Guard stations have greatly influenced the range at which a 1-Watt radio with a six-feet-high antenna can communicate with them.

The RESCUE 21 coverage is designed to provide detection of a one second transmission from a one watt transmitter with an antenna two meters above the water for minimum range of 20-miles. Anecdotal reports from the Coast Guard have mentioned receiving one-watt radio transmission from ranges far beyond the 20-mile minimum.

For more discussion see

http://continuouswave.com/ubb/Forum6/HTML/003322.html
 
Last edited:

BoatFisho

Petty Officer 1st Class
Joined
Oct 12, 2013
Messages
249
No in Aussie but we must have a similar setup re coastguard, but that gives me a good idea of how far in fact transmission can go.

So why do people on Amazon complain about poor reception etc, user error?
 

jhebert

Ensign
Joined
Jul 24, 2005
Messages
903
No in Aussie but we must have a similar setup re coastguard, but that gives me a good idea of how far in fact transmission can go.

Check with the Australian Coast Guard or equivalent agency to find their radio coverage contours. If you are in sight of other boats, you are in radio range. Radio waves always travel beyond the range of light waves due to atmospheric refraction. See

http://continuouswave.com/whaler/ref...ioHorizon.html

For a good discussion of radio range, see

http://continuouswave.com/whaler/reference/VHF.html
 
Last edited:

BoatFisho

Petty Officer 1st Class
Joined
Oct 12, 2013
Messages
249
well that sounds like quality over quantity. im never out of site of other boats thats for shore, usually there will be one within 500m max.

cellphone still works fine, but im wanting a back up system. i considered an auxillary but not very practical on a 13ft rib.
 

UncleWillie

Captain
Joined
Oct 18, 2011
Messages
3,995
The distance to the shore or other boats is irrelevant.
It is the distance to the receiving stations that counts!

30 boats within a mile doesn't help if they don't have radios, or they are not turned ON.

Coast guard stations in my locale are 20-30 miles apart on average.
It is possible to be beached and still be over 10 miles from a shore station.
In some situations, being near the shore is worse for reception than being far out in open water.
 
Last edited:

BoatFisho

Petty Officer 1st Class
Joined
Oct 12, 2013
Messages
249
yeah. im going to go with a 6w handheld as a backup. just not worth the risk.
 

jhebert

Ensign
Joined
Jul 24, 2005
Messages
903
The distance to the shore or other boats is irrelevant.
It is the distance to the receiving stations that counts!

30 boats within a mile doesn't help if they don't have radios, or they are not turned ON.

You are introducing non-technical considerations into the discussion. When one inquires about making radio contact with another boat, there is an assumption that the other boat has a radio, and is monitoring. If you have a radio on your boat, in the USA you are required to maintain a radio watch on Channel 16, and, if a DSC radio, the radio also maintains a radio watch on the DSC channel. When you install a VHF Marine Band radio on a boat, even as a voluntary installation, you are still subject to the regulations to maintain a mandatory radio watch.

Your argument that there is no relevance to the distance between your boat and other boat for radio communication is wrong. Your argument is based on human elements. One could invent all sorts of human elements that could preclude communication taking place. For example, the other boat might not understand the language you are speaking. That does not mean your radio signal did not reach his boat.

Radio coverage for shore stations for an agency like the Coast Guard of the USA is clearly shown in their coverage maps. The goal of the RESCUE 21 project is to provide coverage to at least 20-miles offshore. If you have knowledge of a gap in that coverage that occurs within 2-kilometers of shore, you should point out that location. Otherwise you seem to just be inventing out of thin air the notion that it is possible for a gap in the coverage to exist when very close to shore. Your invention of that claim does not really substantiate it. After spending almost $1-billion on this radio system, I doubt there are any coverage gaps because a boat is too close to shore.
 

BoatFisho

Petty Officer 1st Class
Joined
Oct 12, 2013
Messages
249
Im now looking into a proper VHF fixed mount radio and battery system as i just need to finish the loop from the engine. then i can have lights as well. ill still get a 6w handheld as a back up though.
 
Top