Cell signal amplifier

F

flapbreaker

New member
I don't see this talked about much but was wondering if anyone has any experience with cell signal amplifier/repeater like the digital antenna DA4000 or DA4000MR. I lose cell service at about 15 miles offshore and would like to extend my service out to about 40 miles. According to digital antenna you can extend your signal upto 50 miles if the right conditions exist. I'd probably go with an 8' cell antenna.

http://www.digitalantenna.com/prods/cel ... ifier.html
 
Some of the crusing trawlers have used this type of amplifier. It depends on a lot of factors. The power itself is not as much of a factor as one might think. Remember that with direct line of sight it does not take much power to send a dital signal--even thousands of miles.


But the UHF signal is line of sight--with some ducting occasionally. With a 100 foot cell tower and an antenna which is 8 feet and the benefit of a doubt if you put it on a radar arch which is 6 feet off the water (14 feet),
The "range" will be only 19 miles (by calculation). Also add in that for the most part, cell tower antennas are directional inland, rather than toward the water. (For example our home is only 0.7 miles from a cell tower, but it is inland, and has a marginal cell signal--yet I can get a good signal 4 miles inland off this same tower.) It will be difficult to get the 50 miles unless that transmitting antenna is way up--lets say 1000 feet--on a mountain by the sea, you will get that 50 miles. An example would be an cell tower antenna on the Palos Verde area in S. Calif. or Catalina Island--where this height may be achieved. At Lake Powell, you can get good cell signals when you can visually see Navajo Mountain. In this case as you get to the fringes of reception, an amplifier will help.

You can also improve the signal with a Yagi antenna, which will be highly directional. But again you have to have the line of sight to the tower. There are "home" and "marine" kits which have an external yagi antenna, and a repeater which will work in the home or boat. The home is better, since the antenna is fixed--the boat would have to have a rotor on the directional antenna.

I don't know how many of the cell towers are on moutains along the Oregon coast, but I suspect not too many. We use Verizon and looking at their coverage, there is cut off right at the coast in a number of areas. Ths corresponds with the experience of a friend of mine who is a delivary skipper and who has Verizon and experiences only moderate reception along this coast (He lives in the Portland area).

Jeff Siegel (Active Captain) is working on cell phone reception for coastral cruisers--he has used his cell phone and WiFi while full time cruising over the last 3 years. Cell phone reception is of concern, since Active Captain will be interactive for the various anchorages, marinas, ramps etc--and will be essential for the entire package to work well. I suspect he will have some very definate recommendations in a few months.

I suspect that you noticed the * at the bottom, which briefly gives mention of some of the above.
 
Thanks for the info. I might just have to try it for myself. I suspect that actual experience will vary depending on location. I get about 13-15 miles on my cell phone as it is so even if I could push it to 30 that would be good enough. I just hate not being able to let the family know all is well if I'm out there and running past my return time due to unplanned lights out fishing. I suspect the antenna will be more important however a little power couldn't hurt either.
 
Don't know about Verizon in Oregon but off the coast near Neah Bay, I get good signal about 20 miles out. It's very marginal at 25 miles. Anything but Verizon though and I don't even get signal in the "town" of Neah Bay.
 
thataway":2lokmy7g said:
Jeff Siegel (ActiveCaptain) is working on cell phone reception for coatral cruisers...
Click to expand...
Thanks for thinking of me. I'm a member of C-Brats and come here almost every day. My next boat is going to be a CD or TomCat.

I've experimented a lot with cell and WiFi amplifiers. Last year I kept detailed records of cellular access using different amplifier technologies between the Penobscot Bay in Maine and Vero Beach, FL. We used to have Cingular/AT&T and Verizon accounts. I found the capabilities along the East coast so similar that we cancelled the Verizon account. The only reason we selected AT&T was because we can switch phones easily by exchanging SIM cards (we have about 15 different phones used for software development).

Through the entire area between Maine and Florida, we only had one 20 mile area in North Carolina where we lost digital access. It was on that very straight land cut called the Alligator-Pungo Canal. There's just nothing out there.

We did a fair amount of offshore travel along the coast too. I found that we had 5 bars when we were 20 miles out. At 22 miles it would slip to 3 bars. At 25 miles, we'd lose the signal. We stayed at 20 miles or less which is pretty typical for coastal cruising anyway. It was very, very nice to be offshore answering emails and browsing web sites while the hours ticked by at the helm. I have shortcuts to all of the NOAA broadcasts pages on my phone so we can read any of the weather reports directly on the phone any time we want (no waiting for the forecast to come around on the VHF). The whole experience was excellent.

For cellular amps we tested direct wired amps and wireless/repeater amps. I am very sure that for any non-metal boat less than about 100 feet LOA, a wireless amp will not provide the results that you want. The problem is that there isn't enough separation between the inside and outside antennas. This causes a feedback loop as your phone signal gets picked up by both antennas. It's like the squeal that happens when a microphone is in front of a speaker. The wireless amps fix this by automatically reducing the amplification until the feedback stops. But the reason you have the amp is to get maximum amplification! So the big secret is to use a wired amp directly to your phone. Many phones plug in directly. Others still work fine with a proximity cable that uses Velcro to attach to the back of the phone. A jack is better - pick a phone that has one for maximum range.

And of course, when you have internet access you are also in range for voice calls. All of our friends and family knew when we were doing an "overnight" because we'd be calling them especially after 9:00 pm when the calls were free!
 
despite the fact that my father mother and brother all build or maintain cell towers and systems for various companies I don't know enough about it to help here. I will say that line of sight is the key to getting signal. You also have to take into account that cell towers are not set up for max range in most places. It does not good to have a tower putting out max power in line of sight if there is another tower three miles away. most of the antennas are pointed at the ground in their area not out ward for max range.

As for the sites on the oregon coast, those would be my brother pats. hes the site maintainer for the at&t in that area. All the sites are on mt tops but they are pointed up and down the coast not out to sea. Pat wishes he had a site at sea pointed into the coast. He would get better coverage that way. but he has told me while we were on on mt top that shooting a signal over water has problems of its own. the signal does not keep its strength over water very well. so if you are getting signal 20 mile off shore you are doing pretty well.
 
Thanks for all the good information. I think I am going to buy an 8' antenna and amplifier and give it a go. I won't know how it works until spring but I'll definately report my findings. I'm hoping for about 30 mile range but that may be optimistic. However I thinking the height of the towers along the oregon coast may benefit me.
 
I can't comment on the amplifier, but we have a 8' cell antenna on Discovery. The antenna will usually improve the signal (number of bars) by an average of two bars, over just the cell phone antenna.
 
Thanks to Jeff for his comments, and the point about a feedback loop is an excellent one!

I would think that you would get the most "bang for the buck" with a good 9 dB antenna, and that seems to be born out by some members observations. I would try the antenna first, then the amp. The question is also is a reception problem or a transmission problem? Tlhe antenna will help both.
 
Discovery":3szzevis said:
I can't comment on the amplifier, but we have a 8' cell antenna on Discovery. The antenna will usually improve the signal (number of bars) by an average of two bars, over just the cell phone antenna.
Click to expand...

I found this thread after reading about a yagi antenna elsewhere. Brent, details on your antenna setup, please?

Warren
 
Save yourself some money and get a used sat phone on ebay. When you have no signal on your cell phone there is no signal to boost. We have tried several combinations offshore and none produced a good result. We purchased a used sat phone and purchased a limited number of minutes. Before buying amps and such talk to some of your boat supply stores. They will also tell you the money you will spend just to get a stronger reception does not mean you will get reception further out.
 
cbull":3t72mg6w said:
We have tried several combinations offshore and none produced a good result.
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Yikes! You're amp isn't working or else you're going way further offshore than I've been...or perhaps you're using Verizon. It seems like you're even in Charleston where I have some direct offshore experience.

In November 2009, we went overnight, offshore from Beaufort, NC to Charleston, SC. At Frying Pan Shoals we were about 16 nm offshore depending on how you measure it. Out there, the cellular connectivity wasn't very good - it came and went. As soon as we rounded that and maintained about a 6 nm offshore range, we had continuous data and voice cellular access.

We left Charleston in January 2010 - 10 weeks later after planning to stay for 2 nights! Needless to say, we had an exceptional time in Charleston. We left through the inlet and went again offshore, overnight to Fernandina Beach, FL staying 3-6 nm offshore. We had full data and voice the whole way again. In my midnight-3 am watch, I passed the time by playing on the internet (and watching the radar).

We run with both Verizon and AT&T. What I've noticed is that AT&T does a better job offshore. The Verizon signal seems more focused on land (using more towers but smaller powered ones) and didn't do a good job offshore. That could be a big difference in experiences.

We have a normal 34 dB powered, direct connect cellular amp with a 4 dB antenna on our arch. Articles, how-to, etc. are all on our web site in the Articles/Mobile Phones section. We don't sell any cellular products - the products and uses that we discuss there are all based on experience - not because we're selling anything (you have to watch out for that).
 
Warren,


I am in Rockport, Texas...the TomCat is in Utah. I think the antenna is a Shakespeare 8', I don't remember the model #. It's not amplified, but has a direct wired connection to the cell phone, through a jack I mounted on the overhead. You need to buy the adapter cord that fits your specific cell phone.
IM000169.jpg
The cell phone to antenna jack is on the left above the AM/FM radio. The thin black cord goes to the cell phone.
 
flapbreaker said:

"I just hate not being able to let the family know all is well if I'm out there and running past my return time due to unplanned lights out fishing."
Click to expand...

If that is what you want, there is an alternative method/device available, and the family can not only get a "I'm OK" message, but see where you are, all the time or just when the message is sent depending on your choice of operation modes.

That is exactly why we purchased SPOT, and here is how we use it:

From a post on a thread about SPOT, a GPS/Satellite communication device:

We use SPOT also, A "Check in OK" when we leave the dock, and then we turn on the track mode. Track is then turned off when we reach our destination, and a "Check in OK" message is again sent. The "Check in OK" message is transmitted via e-mail or text message to the designated recipient. The track mode is available to be followed on the SPOT web site for who and when you provide access.

If the second "Check in OK" message is not received, then they can look up the tracking and see where it quit. A call to us on the cell will confirm we are OK, and "forgot" to check in. How ever, if the track ends half way across to Cattle Pass, and we don't answer the phone, a call to the Coast Guard would be in order, especially if there was some time delay and we had actually had the time to complete the trip.

Our Float Plan is updated to our contacts via E-mail, with general trip info and specific boat, gear and passenger info along with the CG local and 800 phone numbers. I have some hesitation in leaving a copy of the Float Plan form in the parked pickup for obvious reasons.

And that's the way it is, .....for now, for us.
Click to expand...

SPOT also has a family HELP button, or a Rescue Initiation button should those situations arise. SPOT is not an EPIRB, so we do not use it like one, but appreciate the multi-use possibilities. I have no idea how it would compare to a used sat phone and time for it's use.

Harvey
SleepyC :moon
 
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