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Old 15-01-2016, 10:32   #16
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Re: What is the range of a handheld vs an integrated DSC VHF?

All other things being equal, antenna height is the critical factor. VHF radio waves travel in a mostly straight line. Thus, anything that can be seen from the antenna can receive the signal.

Longer distances can be covered by raising the height of both the transmitting and receiving antennas. That's how the CG can get 300 mile coverage. Put the antenna on a 100 ft tower on top of a 200 ft hill and the receiving antenna 50 ft above the water and you can communicate a long distance.

AIS receivers can see beyond the visual horizon because most ships put their antennas at the highest point on the ship which may be 100 or more feet above the water. While you can't see the ship from the boat, the antennas on both boats can see each other.

Power counts to punch though other noise and static and to compensate for poor antennas and cables.

See also: Marine VHF Radio - Radio Range How Far Can I Transmit?

And this link has a drawing of antenna to antenna line of sight: Transmit Ranges of VHF Marine Radio
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Old 15-01-2016, 10:51   #17
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Re: What is the range of a handheld vs an integrated DSC VHF?

We have a handheld DSC that the person who takes the dingy to shore carries. We also use it when taking the canoe up rivers away from the anchored boat. The longest distance we've used it in the SF Bay area was when my husband sailed our dingy from Aquatic Park to the Santa Fe Channel (Richmond). Broken reception but he'd check in every 30 minutes with a DSC waypoint that was being logged on our boat anchored in Aquatic Park. Couldn't talk to him after he was behind Angel Island but could get the waypoints the whole way.

I've used the same handheld to check in with the VHF morning cruisers net in San Diego--I was sometimes down at Fiddlers' Cove (South of Coronado) and while I could always hear others on the net including ones way over in Mission Bay, only the boats within about 3 miles of my position could hear me.

I'd go with the fixed antenna and fixed VHF radio.
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Old 15-01-2016, 11:12   #18
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Re: What is the range of a handheld vs an integrated DSC VHF?

It's better to get a base station with a good mast head antenna. I have very limited reception distance, even in the bay, on a handheld, but CG has Rescue 21 so theoretically they should be able to pick up a handheld a ways offshore. I think there's also a tower on the Farallones, but you'd need to confirm this. I did the BAMA Doublehand Farallones race one year and I know they test a lot of this stuff. Get in touch with the Race Committee there and find out what their results have been. And you might want to read the rules again. I'm pretty sure a handheld is not allowed....you need a fixed station. Ideally, in my opinion, this would include a remote mic to the helm.
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Old 15-01-2016, 11:33   #19
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Re: What is the range of a handheld vs an integrated DSC VHF?

If possible, get the fixed mount radio. But it will only be as good as the antenna and cabling installation.

A handheld makes a good backup. However, a handheld is only as good as its batteries.

I have "broken squelch" with a handheld radio (5watts) from 20 miles away. So it really is about line of sight, not power. When using a handheld, get as high as possible. Some handhelds allow you to insert a cable between the radio and the antenna, allowing you to boost the antenna up a little higher. There is no rule saying you can't use a handheld radio connected to your masthead antenna, if you have the right connections. I've done this myself with excellent results.

I have had great success buying good quality used radio equipment very cheap at yard sales and kijiji.

A good quality handheld is a great thing to have. I have found that most of my vhf use is short range...entering a marina, going through a canal, or calling a nearby boat. The convenience of the handheld is wonderful.

I would suggest you splurge and get a fixed mount set, and a handheld. They are both quite cheap (especially used) and give you a lot of functionality for your dollars.

I use a pair of these I bought used for about the same price as buying one new...and they work great: Uniden Atlantis Hand-Held 2-Way VHF Marine Radio - Walmart.com
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Old 15-01-2016, 12:23   #20
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Re: What is the range of a handheld vs an integrated DSC VHF?

Quote:
Originally Posted by MatthewDurst View Post
I've been trying to figure this out, but to no luck. I understand that an integrated DSC VHF will have a longer range (and by integrated, I mean one that uses the VHF antenna in the mast), but what's the range on a handheld?

Long story short, I'm planning a trip around the Farallon Islands off of San Francisco Bay. But I want to make sure I have all the necessary safety equipment first (ePirb, Liferaft, and DSC). The nearest Coast Guard station is around the Gate, shielded by a mountain. Would the DSC signal still get through if we're out by the islands 23 miles offshore? Would a handheld VHF DSC still make it through?

And if I have the DSC, would I even need an ePirb or is that overkill?
Oh sorry, I just equated "trip" with a race. Another thing to consider is that the lee side is where most sail boats get in trouble, if you are planning to round Southeast Farallon. That's also where "line of sight" is going to be a problem. I think the islands are also more like 27 miles from San Francisco than 23. You might want to check that as it could add a couple of hours to your trip.
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Old 15-01-2016, 12:36   #21
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Re: What is the range of a handheld vs an integrated DSC VHF?

You might want to double check, but hand-held dsc mmsi is linked to an owner, and not to any particular vessel which could add slight complication in an emergency. Also many second hand dsc stuff will need the mmsi changed which might require a visit to the service department or dealer.

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Old 15-01-2016, 12:40   #22
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Re: What is the range of a handheld vs an integrated DSC VHF?

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Originally Posted by Sandero View Post
VHF is line of sight... and then consider the power output.
So if you climb to the top of your mast when using your hand held it would be better but still have less range than your mounted VHF due to lower power.

I believe hand held transmit range is around 5 miles....
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Old 15-01-2016, 12:44   #23
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Re: What is the range of a handheld vs an integrated DSC VHF?

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Originally Posted by thomm225 View Post
So if you climb to the top of your mast when using your hand held it would be better but still have less range than your mounted VHF due to lower power.

I believe hand held transmit range is around 5 miles....
The gain of the antenna is a factor as well.

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Old 15-01-2016, 13:19   #24
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Re: What is the range of a handheld vs an integrated DSC VHF?

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Originally Posted by estarzinger View Post
...On the more general question, I have always been interested and somewhat puzzled by the 'vhf range' question. On the one hand people say it is all about radio line of sight and that you can hear a 1 watt signal back from the moon. But on the other hand, we all know that the low power setting on our radios does in fact seriously cut their range (even using the same masthead antenna) and handhelds typically have really limited range. So, it has always seemed to me that it is in fact not 'all about line of sight' and that power (including antenna gain) does in fact matter significantly to effective transmit range. But I have never seen a range calculator that captured this.
You're absolutely right, & it's an excellent question. The part most folks don't understand is that the signal strength from a "point source" radio signal expands spherically, so it decreases by the square of the distance. So a signal received at 20nm is only 6% as strong (1/(4x4)=1/16) as that same signal received at 5nm (other aspects being equal).

Our VHF antennas are not quite "point sources". The radiated signal isn't spherical - it's more like a doughnut around the whip antenna, with little or no signal going out along the axis of the antenna, & most signal going out to the sides. Higher gain (longer) whip antennas squash this doughnut, putting more signal out to the sides, but less vertically. Monohulls need the shorter (lower gain) whip antennas because they need the signal to go out to the side even when they're heeled over, so they need more vertical signal than powerboats. (Interestingly, this means that most multihulls CAN use high-gain powerboat whips, which can increase their VHF range considerably - but watch out for mounting issues, as there's a lot of whipping motion at the masthead of a multihull.)

If we assume that all the VHF signal went out in a plane perpendicular to the axis of our whip antennas, then the signal would only decrease linearly with distance. So the signal strength at 20nm would be ~25% (1/4) of the strength at 5nm. In practice, the signal drops off somewhere between linearly & the square of the distance.

The point is that while VHF radio signals continue to travel outwards through line-of-sight, at some point the signal strength becomes too weak for domestic radio systems to detect. So while it's true that you can receive a 1W signal from the moon, that signal is very weak - you need a concentrating dish & a very sensitive detector to hear it.

Those folks who have commented that the antenna system is more important than the radio are absolutely correct. The small incremental gains you get by going to an expensive radio (more sensitive, since we're all limited to 25W) are nothing compared to spending a bit more on a good antenna & low-loss cabling (which improves both xmit & receive).

VHF antennas should be connected with RG-8 coax, not the thinner, less expensive RG-58. Poor cabling (or water leaking into the cable at the antenna connection) can easily cut your signal in half (on both xmit & receive). Use RG-8 coax for any runs over ~30' (10m), use good quality connectors (soldered if possible, & the fewer the better) & wrap the antenna connection with self-amalgamating tape (available at most hardware/electronics stores) to seal it from water getting in.
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Old 15-01-2016, 13:39   #25
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Re: What is the range of a handheld vs an integrated DSC VHF?

Quote:
Originally Posted by MatthewDurst View Post
I've been trying to figure this out, but to no luck. I understand that an integrated DSC VHF will have a longer range (and by integrated, I mean one that uses the VHF antenna in the mast), but what's the range on a handheld?

Long story short, I'm planning a trip around the Farallon Islands off of San Francisco Bay. But I want to make sure I have all the necessary safety equipment first (ePirb, Liferaft, and DSC). The nearest Coast Guard station is around the Gate, shielded by a mountain. Would the DSC signal still get through if we're out by the islands 23 miles offshore? Would a handheld VHF DSC still make it through?

And if I have the DSC, would I even need an ePirb or is that overkill?
Lets make this really simple.

Install a station radio for safety. If budget permits, add a handheld for convenience.

If your life depends on it, you want the maximum VHF range achievable.

Full disclosure: I sell and install VHF equipment. This advice is offered free and not intended to solicit business.

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About Sheen Marine
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Old 15-01-2016, 14:17   #26
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Re: What is the range of a handheld vs an integrated DSC VHF?

Quote:
Originally Posted by MatthewDurst View Post
I've been trying to figure this out, but to no luck. I understand that an integrated DSC VHF will have a longer range (and by integrated, I mean one that uses the VHF antenna in the mast), but what's the range on a handheld?

Long story short, I'm planning a trip around the Farallon Islands off of San Francisco Bay. But I want to make sure I have all the necessary safety equipment first (ePirb, Liferaft, and DSC). The nearest Coast Guard station is around the Gate, shielded by a mountain. Would the DSC signal still get through if we're out by the islands 23 miles offshore? Would a handheld VHF DSC still make it through?

And if I have the DSC, would I even need an ePirb or is that overkill?
Transmission rule of thumb is one mile per watt. Handheld at 5 watts is 5 miles. Ship Station VHF at 25 watts is 25 miles. This is line of sight, higher the antenna, greater the range. VHF signals are received by aircraft from a boat 200+ miles away and have been known to assist in rescues.
An EPIRB is a must on any vessel navigating offshore.~~PERIOD>
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Old 15-01-2016, 14:48   #27
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Re: What is the range of a handheld vs an integrated DSC VHF?

Having for years used cheap radio gear because of budgets I finally got fed up with all the problems and splashed out on a top quality Icom unit. What a revelation, double the range and withe a good aerial I have often had clear com's at 30-50 miles. Don't get seduced by the bells and whistles you want solid industrial quality electronics and casing with big simple buttons. Also ye the aerial is vital to range, for the price replace it, again with good tinned cable. Good com's turn disasters into incidents
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Old 15-01-2016, 15:39   #28
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Re: What is the range of a handheld vs an integrated DSC VHF?

its only 26 miles, you cell phone works out there so don't worry about the VHF, sector san Francisco will be able to hear you even at 3 watts


you can smell the islands before you can see them
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Old 15-01-2016, 16:38   #29
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Re: What is the range of a handheld vs an integrated DSC VHF?

Quote:
Originally Posted by MatthewDurst View Post

The nearest Coast Guard station is around the Gate, shielded by a mountain. Would the DSC signal still get through if we're out by the islands 23 miles offshore? Would a handheld VHF DSC still make it through?

And if I have the DSC, would I even need an ePirb or is that overkill?
Great question! You're not actually talking to the Coast Guard stations, but rather to an antenna on the top of Mt. Tam, and an operator who is at Yerba Buena Island in the Bay. The Coast Guard's Rescue 21 system will pick you up at the Farallones (not on the back side, but either side) with a handheld radio that's 2m above the water, or so the specification says. So, if your only task was to talk to the Coast Guard, then a handheld VHF especially with DSC, would do the job.

However...

If you want to talk to other vessels, or shore stations that don't have an antenna on Mt. Tam, you'd be much better off with a fixed mount radio and a quality antenna installation on your masthead. Figure 2 miles transmission with the handheld to another sailboat, and perhaps 20 miles with your fixed mount antenna.

And the vessel that comes to your aid might be just another gal or guy who's taking a sail about SE Farallon and Maintop Islands.

Finally, yes, there is a good reason to also carry a PLB or EPIRB, and that is their independence from all of your vessel systems. You can sink, lose your mast, have a fire, run your batteries down, etc and the PLB or EPIRB still works.

Cheers,

Chuck Hawley
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Old 15-01-2016, 17:05   #30
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Re: What is the range of a handheld vs an integrated DSC VHF?

I have been able to converse with traffic control out beyond the San Francisco TSS and near the Farallons using my ship's VHF/masthead antenna radio. Using the same radio I cannot reach a race committee VHF (with whip antenna) located at the Golden Gate Yacht Club (just inside the Golden Gate) until near the eastern end of the shipping channel.

Before recently installing the present ship's radio and masthead antenna, using a handheld I had difficulty talking to another nearby sailboat (less than a mile) in sporty weather also near the Farallons, I think because line-of-sight was being blocked by large swells. In this case, probably the other boat was also using a handheld.

Obviously, the ship's radio is going to be better. Best to have a remote in the cockpit so when stuff hits the fan you don't need to go below to use the radio.
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