Cell boosters and antennas?

[thoward]

I picked a cell antenna this past weekend and wanted feedback on the boosters that go with them. I have heard they will boost anywhere fron 20-50 miles offshore. Who has them and what do you think? Also, did you hook direct to the phone or did you go to a remote telephone?

 

[(Nobody You Know)]

Though I have not done this yet I read in a popular boating magazine (can't remember which one) that tested several booster systems. This, a lower cost unit, got rave reviews:

http://marinetechnologies.net/

Hope this helps.

 

[Mike53C]

I have the Wilson amplifier and what they call a trucker antenna. I bought two spring mounts, and take both amplifier and antenna when I go to the marina. I use a rural road with marginal or non existing signal. While in the car, the connected cell picks three strenght bar signals. While at the boat I some times anchor close to the marina, but behind a mountain that blocks completely the signal. No problem with the combo now mounted in the boat. I have not tried it offshore, but I would say that obstructions in the line of sight of the cell repeater are worse than open sight distance.
Now that I know it works I plan to get another amp and antenna and have both mounted in a permanent way, SUV four wheeler and boat. I use a direct connect, not the wireless.
This guys attend the Miami Boat Show, I got it there at a better price than thru internet. Quite helpful people too.
http://www.wpsantennas.com/index.asp?PageAction=VIEWPROD&ProdID=3
Miguel

 

[JLR]

Keep your eye on your wallet. I am sorry to say that when I looked at these several years ago, I came to the unfortunate conclusion that most were snake oil. Be careful and clearly define what you are looking for.

 

[Nonchalant1]

I installed the Digital Antenna DA4KMR-30U on my 53MY 2 years ago and I can not say that it improves performance. I asked Digital Antenna about it at the Miami boat show and they said I had to have 40 ft. of separation between the bottom of the high antenna and the top of the indoor repeater antenna in the boat, which I don't, because the installation instructions said I only had to have 20 ft The installation instructions also say that the indicator light on the amplifier will glow green if everything is OK, which it does. It further states that if the antennae are too close, the indicator will glow red, which it doesn't.

Either way, I have an expensive system, difficult to install, and I can't see any improvement in the performance. At the show, a salesperson told me I should try the new directional indoor antenna, for more money.

Based on our forum policy, I have just stated the facts as they apply to me with first hand experience. I let you draw any conclusions you want.

Doug Shuman

 

[Genesis]

Cell signals are line of sight.

Period.

Therefore, you need to know what height the tower is at which you're trying to talk to, etc.

The higher your antenna the better, and an amp helps but its not a panacea.

 

[Boss Lady]

You have to deal with the curvature of the earth since cellphones operate at microwave frequencies and are purely line of sight. Also the cell phone companies use antennas with down tilt to minimize the footprint of each tower, so anything beyond 5 miles from the tower is either the result of a mis-aimed antenna or a reflected signal. The towers are high enough to provide roughly 14 miles of line of sight coverage but microwave signals are very weak signal strength at this distance. I have a cellphone range extending amplifier (repeater) and high gain omni antenna. We have gotten coverage out as far as 18 miles. You can improve the range with the use of a bi-directional amplifer and a high gain antenna. Not all electronics are created equal and neither are antennas. There is a lot of garbage on the market both expensive and cheap, there is also some really cheap equipment that can best the most expensive. If anyone is interested I can go look up and post the stuff I am using. It cost $450 bucks, not cheap but not too expensive. It is also dual band so my guests can use it as well. It is a repeater. The high gain antenna is the real key to the system working so well, the low noise amplifier boosts received signal strength and the amplifier ensures adequate transmit power.

 

[ThirdHatt]

I did some research on this TODAY. It seems that Digital Antenna makes the best quality marine antenna's out there. I have been looking into their systens for over a year now and I have seen several updates/improvements and new antennas come out. They also make some excellent complete systems, but they really have to have AT LEAST the specified separation between inernal and external antenna's to get any "boost" at all. That is why I have decided to get the wired version, not the wireless. I don't need to walk around my boat when I talk, I can sit at my "desk" to the left of the helm. For $20 you get the adapter for your cell phone, ~$250 for the amp, $150 for the antenna and $75 for the cable. $500 total and you have a direct connection to and through the booster to the 9db gain antenna on the flybridge. With a wired system there is no doubt if you are getting the amplified signal, so Doug I would call them and get the adapter for your cell phone that connects to the amp. I bet you notice a huge improvement! You can even get a splitter and connect up to four guests cell phones (with appropriate or universal adapters) to the booster/antenna as well. This system should serve me well in the Bahamas where GSM coverage is widely available, albeit spotty due to large distances between towers.

For much better use of the many wifi hotspots in the Bahamas, I plan on buying a 10db gain 2.4ghz Wifi antenna from Digital Antenna. I will connect it to their low-loss cable (same as cell booster to antenna cable), then to my laptop aircard. In testing they got just over 1 mile line of sight. $150 for the antenna, $75 for the cable and a $60 wifi card that will take an external antenna. This system should prove to allow wifi usage AT ANCHOR, not just in the marinas.

 

[Boss Lady]

The seperation requirement is for when the two antennas (the high gain and the repeater antenna) are in the same horizontal plane. If your high gain is mounted up high, like on the radar arch and your small repeater antenna is mounted in the salon you will have enough vertical seperation that the amplified signals will not interfere with your handset. You can also put a ground plane beneath the high gain, by using aluminum paint or a small piece of sheet metal, this will further isolate the high power antenna from interfering signals below it. High dollar does not automatically mean high performance. The signal loses in the connectors and type of coax can be extreme at microwave frequencies. I would not necessarily rely on a magazine review of one of these systems, it can be a starting point, but I would ask fellow boaters to see their installation and what kind of performance they get. Also a poor installation can negate any performance increases.

 

[Nonchalant1]

Boss Lady and Third Hatt - Thanks!
My 1 ft. high gain antenna is mounted on a 6 ft. antenna mast above the radar arch. The bottom of the high gain is 14 ft. above and 8 ft. aft of the repeater antenna in the helm cabinet and they're both vertical. I used only the cables and connectors that came with the system from Digital Antenna.

D.A. says they have special key codes for every cell phone so you can get the phone to read out signal level actually received from the cell site. Then you can get a reading with the system off and with it on and compare. I may try that, or maybe I'll just not worry about it.

Doug

 

[Genesis]

I have "engineering mode" on my handset (I hacked the firmware) so I can see EXACTLY what is going on with signal strength and such.

Not all handsets have this enabled and available - but if it is, its a GREAT tool to figure out exactly what is going on.

 

[bobk]

I too tried a DA antenna and wired amp. The results were strange. I got more signal strength bars at Baltimore Yacht Club (a Verizon desert) but weaker voice reception and transmission. DA couldn't explain the phenomenon, but a knowledgeable member of another forum had what I think was the most plausible explanation. He said when the cell signal was strong enough to hit several towers at once, the tower would automatically reduce the cell signal. Go figure, but the result was a lot of time and money spent for nothing. I unfortunately didn't get around to installing the antenna until I had it a month or more, so the vender (CME) didn't want to take it back. It took a lot of hasseling to get a refund, and I was out shipping and restocking fees. Snake oil??

Bob

 

[60hatt]

what ever you do stay away from the digatl product line .i have tried one also and it does not work. they came up with every reason in the world why the amp did not perform . i now have a wilson works great.

 

[Boss Lady]

The signal strength bars measure field strength and are equivalent to the Fish Liar in reliability, LOL. The engineering mode that Karl refers to, is a real measurement on the actual channel pair you are working, and You can get erroneous readings from the user (what you and I see on our phones) meter, since it is reading all RF signal in the frequency band. For instance, if I am near you with my boat, "my" repeater will peak everyones phone and they would think they have excellent signal but may not be able to make a call, because my amplifier is actually jamming them. Unless they are within the very short radius of my indoor antenna, the outdoor antenna will give them the false impression that they are getting good signal from the tower, when in fact they are only getting strong signals from my repeater output. If your phone can be programmed into "drive testing" mode you can see a lot of information about the CDMA phone system.

 

[thoward]

I was thinking this was going to just be a plug and play deal . I got a Shakesphere antenna so my final decisions are amp brand and if I want to put an extention on the antenna to get it even higher(25')

 

[jim rosenthal]

Just a question...even digital cell phones are two-way radios, right? They transmit and receive on two different bands, even though they may be close together, I would think. So pushing out a strong signal is not the same as being able to receive signals from far away, isn't that right? As in: you can amplify your transmit signal, or use a better antenna to push it out, but you still won't be able to hear the other guy unless you have a better receiving antenna AND an amplifier and filter on the receive signal. Set me straight if I am mistaken...

 

[Boss Lady]

two way radio is like two tin cans and a string compared to the complex signaling going on to make a phone call on the CDMA cell system. The cdma system uses ONE BIG channel, and it is a spread spectrum wave form. You can also be communicating with up to 4 different cell towers simultaneously to support one call. All the cell towers are connected to a large switch center which decodes all the digital data packets from each of the cell towers supporting you call and rejects the bad packets and reassembles the good ones, the cell tower is also controlling the rf power output of all the phones which it is supporting active call connections, and it can increase or decrease your handset power output every 20 milli-seconds, Needless to say this is very complex. You can just about forget what you know about radios, except for the fact that you transmit and receive, radio frequency energy and still need antennas. If you want to know more I am sure that it is on the net.

Oh yea, the channel pairs are not seperate frequencies, but are time segments within the frequency hopping spread spectrum channel, which is kind of like encryption. This is the clep version of all of this. But I hope you get the picture.

 

[jim rosenthal]

Got it, or at least the part that lets me know I am not smart enough to get the rest....

 

[tomrealest]

I have the Digital Antenna cell phone amplifier products. DON'T WASTE your money. I started with the antenna, amplifier,and hard wired cell cable. NO IMPROVEMENT. Talked to them at the Miami Boat show and they gave me all kinds of excuses and reasons why. Like a fool, I had one of their dealers install in the V-berth another amplifier. Same run around as the first time. Great publicity but I can't get the products to help me.

 

[Boss Lady]

Tom, which company provides your cell phone service? You may have been sold a repeater that is not compatible with the frequency band of your provider. I see this a lot, Sprint is in entirely different spectrum, and so is Cingular. I have not seen a repeater system for their spectrum bands.