– Last Updated: Jun-17-09 6:29 AM EST –
This is your original post..
"For example the Icom 36 does not have great battery life relative to non-floating radios...
Personally I like the Standard HX-270 since it is bullet proof and inexpensive. The Icom M-72 is nice too."
So your vhf that gets 13 hours and the M34 gets 12 hours?
Yet yours is bullet proof and the Icom M34 could ruin someone’s day?
Your reasoning doesn’t make sense and the facts don’t support your claims. Yet you keep on pushing this misinformation.
By the way your battery cost $70 to replace and the M34 is $50 and the I72 is $130. You do the math. Which vhf has a battery issue?
I have nothing else to add.
Edit: the M34 has excellent range. I live on one of the major US ports, 5 miles from CG and 10 miles from Sea Tow. Icom is very rugged. All vhf have limitations, but the M34 also has the advantage of a longer antenna. It also floats so I can hand it to someone else if the group decides to split up, or I have to perform cpr, etc.
This is p.net so sometimes it gets personal, but congrats to all for making that help rather than hinder getting out some good information.
some of the posts have shed some new light on manufacturer claims and real world differences. Thanks, I learned some new things.
The M88 battery “compartment”…
…is not sealed, per se. Actually, it’s not a “compartment”, either. The sealing system is different than you might expect - it’s essentially triple sealed - and here is how it works:
The body of the radio is sealed and the sealed battery attaches to the back of it. The only vulnerable point on the radio back is the battery contacts. They are sealed internally (seal 1) to prevent water from entering the radio body and that area is also protected by an external O-ring seal (seal 2) to prevent water from reaching the contacts. The tight-fitting battery acts as a labyrinth seal (seal 3), preventing most water from getting to the O-ring, but it’s normal for a drop or two to get between the battery and the body and it can’t do any harm there. If Sea Kayaker saw that as a problem, it’s due to a lack of understanding of how the M88’s sealing system works, not a flaw in the design of the radio.
It’s a very smart design, as the labyrinth seal reduces exposure of the O-ring seal to water and using a small O-ring to seal only the area around the contacts is much more effective than trying to seal the entire back of a radio with a much longer O-ring, which is what some other manufacturers try to do, often unsuccessfully. It’s also much less prone to contamination from sand/grit/salt, and much easier to clean if it it does become dirty. If anything, radios that use only a single perimeter seal between the battery and an unsealed radio body should be viewed with suspicion, as they require extra care in assembly to keep them clean and watertight. The O-ring on the M88 prevents water from getting to the battery contacts, but even if it does, it still can’t get into the radio due to the internal sealing. However, salt or mineral buildup can cause problems with with the spring-loaded contacts, so the O-ring is necessary.
In use, I have never seen more than a drop or two of water get between the battery and radio body and I don’t recall ever seeing any reach the O-ring around the contacts, let alone penetrate it. This includes a lot of time spent swimming and rolling with the radio on my PFD.
The only maintenance required is to keep the O-ring clean and lubed occasionally with silicone grease, which is what you should do with any O-ring seal on any radio. Putting a little grease on the contacts provides further insurance against salt/mineral encrustation if water should happen to get past the O-ring.
IIRC, the M88 is the only marine VHF of it’s type that is used by the US military. That should tell you something about the robust nature of its design.
DSC will be important
Once the CG’s Rescue 21 is operational, it is in some locations now, DSC will be a very nice if not important feature for a VHF marine handheld radio. I expect more models will be on he market soon and may justify getting a new radio. With DSC your accurate position and type of distress situation will be sent to the CG without the need to say anything and you will be notified if they have received you distress call. This sure beats being asked to slowly count to ten or whatever so they can attempt to get a rough radio fix on you which is the procedure used without DSC.
it’s just an info thread…
– Last Updated: Jun-17-09 12:45 PM EST –
No hard feelings.. ;)
The CG tower here can pick up a handheld from at least 30 miles away. there was a kayaker last year that put out a mayday when they were capsized about 30 miles away. No one knew where they were and I assisted in helping triangulate the location. I was able to confirm that a second mayday call was not from the same location, as my handheld couldn't have picked that up 30 miles away. As it turned out someone else was relaying the same mayday call. The kayaker was rescued by another power boat.
At any rate I know the CG can hear me and I feel secure in the 30 mile range. There is also a lot of other boats with vhf. I carry a GPS to let them know the exact location.
On the first day I turned on my VHF there were 5 rescues that I monitored, two of them serious.
I'm also looking at a PLB now that good ones are down to $300.
Edit: If out solo in the ocean I stay within 5-10 miles of the CG tower. They did say they picked up the handheld from 30 miles away, though that was just one rescue. I also haven't scratched my first layer of defense and have successfully rolled up after capsizing, also within swimming distance of a sandy beach etc.
– Last Updated: Jun-17-09 2:40 PM EST –
"The CG tower here can pick up a handheld from at least 30 miles away."
It is often said Marine VHF Radio is a line of sight system. This is not absolutely true of signals in the VHF range, but regardless of the propagation issues; the CG's system has far better coverage than the "line of sight" mantra suggests and more in tune with Yakwise's post. The Rescue 21 system is designed to provide communication with a 1 W radio at 20 NM. Whether that is 1 W handheld or portable makes a big difference and I forget which it is.
about the The Rescue 21 for the Coast Guard. As far as the line of sight for portable, the sail boats mount their antenna up on the top of the mast for increased range. I would guess the CG use the same four feet above the ocean surface for range of sight for markers. If it’s lower than that, of course, the range decreases. I don’t even consider 30 miles to be a good range, and that’s the rule of thumb I use in this particular area, mostly because there are a lot of other boats as well in the same area, and 30 miles south or north gets more remote. Other boats that drift out to sea, actually can see a lot of other cargo ships pass but the cargo ships don’t see them. Those two kids were brushed by a cargo ship but no one saw or heard them. They finally got spotted by a fishing boat after over 10 days with no water in the summer.
A good $100 waterpoof vhf and a $300 plb with gps seems like a good combo.
Couple of details
According to some documentation on the system, the 20NM range is based 1 watt six feet above water and that is minimum spec for system. Found nothing about assumed radio. 1 watt into a large antenna on boat is very different than 1 watt from handheld. In some tests a Rescue 21 system was able to communicate with commercial vessels at 100 NM offshore.
“In some tests”
“In some tests a Rescue 21 system was able to communicate with commercial vessels at 100 NM offshore.”
Likely marine layer signal trapping (you SoCal guys may understand as it is common there). Nice when the atmospherics are in you favor…
Ah, what do I know? In a former life I was just a squid wx guesser trained in EM propagation and such…