On 9/12/2013 6:24 AM, Geoffrey S. Mendelson wrote:
rickman wrote:

Yes, that is why I want to support the kayakers on the paddle next week,
as a safety measure. Last year we had a stiff wind from the north which
created significant waves at the start and a number of paddlers were not
able to make it all the way. I was part of the team which tracked their
progress and got them off the water. Cold was not an issue in this
case. Cold water makes such events much more dangerous. That is why I
want to have good radio communications.

IMHO you would be far better off having them get cellphones with GPS
in them and have them phone in with their exact location if they need help.

You don't need a waterproof phone, if you double bag it in one of those
plastic bags sold to boaters to keep things dry, you should be ok.

I don't know how close to the shore they intend to stay, but if they get
far enough out, the conversation about where they are is something like:

"What do you see in front of you"? "Water".
"What do you see behind you"? "Water".
and so on.

Or even worse, when the answer to that question is "Fog".

I take it you have not read the full thread, that's ok. Cell phones
only work within range of a tower. The bay is miles wide and many areas
where we paddle have little or no cell phone coverage. Lake Anna is the
same. I have needed to use my cell phone while paddling only to find it
can't dial a number.

We always carry cell phones because they are useful when they work, but
we never rely one them. In fact, we never rely on any one safety
mechanism working. We always have a backup or two. That's why the
radio is useful. It can work when the cell phones don't and it can do
things a cell phone can't, like reach someone close by without knowing
their phone number.

--

Rick

rickman wrote:

I take it you have not read the full thread, that's ok. Cell phones
only work within range of a tower. The bay is miles wide and many areas
where we paddle have little or no cell phone coverage. Lake Anna is the
same. I have needed to use my cell phone while paddling only to find it
can't dial a number.

Why are you so belligerent? Yes, I have read the entire thread, and I am aware
of the size of the bay.

GSM cell phone coverage is limited by timing to 35km, about 5-10 times the
range of a VHF handheld. If an 850 mHz GSM phone is not going to work
where you are then a handheld won't reach land either.


We always carry cell phones because they are useful when they work, but
we never rely one them. In fact, we never rely on any one safety
mechanism working. We always have a backup or two. That's why the
radio is useful. It can work when the cell phones don't and it can do
things a cell phone can't, like reach someone close by without knowing
their phone number.


But that was not the point of this whole ****ing contest. It was based upon
your mistaken understanding that you could put a 25 watt boat radio in
your truck ON LAND and reach kayaks in the water.

The laws of physics being what they are, yes you could probably go fairly
far with a 25 watt radio, a good antenna and height and with a receive
preamp and a beam antenna be able to hear across the entire bay and
possibly be heard.

Since that is not an option, you are stuck with a handheld radio and a
rubber ducky, which will get you a couple of miles on a good day if you
are on land, and more if you are on water.

Come to think of it the best suggestion was to have someone build a decent
listening post on high ground (or with a tower) and relay information
to someone via cell phone on the water.

The are AFAIK no restrictions on land based fixed receivers and you could
take old Motorola Maxtracs (available for almost nothing these days),
connect them up to 3 element beam antennas, add a cheap receive preamplifier
and hear everything on the bay if you had enough receivers with their
antennas spread in an overlapping pattern.

Geoff.
--
Geoffrey S. Mendelson, N3OWJ/4X1GM/KBUH7245/KBUW5379

On 9/13/2013 3:59 AM, Geoffrey S. Mendelson wrote:
rickman wrote:

I take it you have not read the full thread, that's ok. Cell phones
only work within range of a tower. The bay is miles wide and many areas
where we paddle have little or no cell phone coverage. Lake Anna is the
same. I have needed to use my cell phone while paddling only to find it
can't dial a number.

Why are you so belligerent? Yes, I have read the entire thread, and I am aware
of the size of the bay.

I'm sorry. I didn't think I was being belligerent. You make a
suggestion that has been offered several times and has been explained
how that is not a viable solution several times, so I assume you have
not read these. Where was the belligerence?


GSM cell phone coverage is limited by timing to 35km, about 5-10 times the
range of a VHF handheld. If an 850 mHz GSM phone is not going to work
where you are then a handheld won't reach land either.

You are making false assumptions. First, the cell phone doesn't need to
reach *me* a mile or two away. The cell phone has to reach the cell
phone *tower* which is in an unknown location. You are trying to
guesstimate where cell phones will work and I have been there and found
where they wont work as have others. Proof of the pudding... Also,
this isn't just about the trip on the bay, I am looking for a general
solution which applies at Lake Anna and other locations as well.


We always carry cell phones because they are useful when they work, but
we never rely one them. In fact, we never rely on any one safety
mechanism working. We always have a backup or two. That's why the
radio is useful. It can work when the cell phones don't and it can do
things a cell phone can't, like reach someone close by without knowing
their phone number.


But that was not the point of this whole ****ing contest. It was based upon
your mistaken understanding that you could put a 25 watt boat radio in
your truck ON LAND and reach kayaks in the water.

I have not seen anything that says I can't do that. I have been told
that I must get a license for land operation. I'm still not clear on
just what type of land operation I am allowed to use.

I don't consider this a ****ing contest. If you are getting torked off
about it, why do you respond? Please, I genuinely am just trying to
discuss this. If you think I am being belligerent and want to **** off
people, you are mistaken. It might be best if you didn't continue the
conversation.


The laws of physics being what they are, yes you could probably go fairly
far with a 25 watt radio, a good antenna and height and with a receive
preamp and a beam antenna be able to hear across the entire bay and
possibly be heard.

Since that is not an option, you are stuck with a handheld radio and a
rubber ducky, which will get you a couple of miles on a good day if you
are on land, and more if you are on water.

Come to think of it the best suggestion was to have someone build a decent
listening post on high ground (or with a tower) and relay information
to someone via cell phone on the water.

The are AFAIK no restrictions on land based fixed receivers and you could
take old Motorola Maxtracs (available for almost nothing these days),
connect them up to 3 element beam antennas, add a cheap receive preamplifier
and hear everything on the bay if you had enough receivers with their
antennas spread in an overlapping pattern.

Thanks for your input.

--

Rick

On 9/13/2013 7:29 AM, Jeff wrote:

GSM cell phone coverage is limited by timing to 35km, about 5-10 times
the
range of a VHF handheld. If an 850 mHz GSM phone is not going to work
where you are then a handheld won't reach land either.


That is not correct of course; as it depends on where the cellphone
towers are located wrt to the user, and the terrain in between.
The OP has already stated that there is no cell phone coverage in the
area, so the 35km range is a moot point. He may only wish to talk to the
kayaks a few hundred yards away, but if you don't have any cell phone
signal you can't !!!

Yes, the issue is not how close land or the other kayakers are, it is
the distance and terrain to the cell tower.

Just for the sake of accuracy... If I said there was *no* cell coverage,
that was a mistake. Cell phones work in some areas and we *do* have
cell phones with us when we paddle. But the coverage is spotty and we
can't rely on them just as we can't rely on marine VHF radios.

Cell phones are also very difficult to operate compared to a push to
talk radio. If you are in a situation where the wind has picked up and
you are fighting waves you don't have the opportunity to pull out a cell
phone and dial up numbers. You are lucky to be able to take one hand
off the paddle long enough to push the talk button.

--

Rick

rickman wrote:
snip

Just want to say, this has been an entertaining thread to read!

--
If the above message is full of spelling mistakes or the snipping is duff,
it's probably because it was sent from my iPhone, likely whilst walking.
Apologies!