I have a couple questions concerning antennas.

VHF: I am going to replace one and add a second radio this year. what is the way to go for a cabin top mounted VHF antenna. I know taller is better and I know about gain but can/should you mount a 14' antenna on the roof? I was thinking about a couple 8'ers with 6db gain. But I would get a little more distance with a 14'er. But do these need support midway or can they be base mounted like the 6 and 8'ers. I think the formula for range is something like sqrt(height in feet above water) * 1.42 = range in miles
or something like that so we are talking in the 5-7 mile range.

There is a guy who fishes near me who has amazing strength and range. I can hear this guy clear as day 25 miles away, and I can't figure out what he has. I have even spoken to him (saw him in west marine one day) and asked him directly. He says it is his antenna...I think he has is radio jacked up and is pumping out more that 25 watts...


Cell phone antennas. Exactly how do these work? I see cell phone antennas that can boost your rangeon the water to 20-40 miles in some cases. Do the cell phones need to be directly plugged in to the antenna or is there some magic going on between the roof mounted device and the phone locally that boosts the range somehow?

I have a 10 foot Shakespeare galaxy on top of an 8' extension on a vintage regency polaris direction finding radio and can talk over 20 miles. They need support brackets or it'll break the antenna eventually. I think also important is extremely good connections.

I think cell service is network dependent. AT&T works well offshore around here Verizon does not.
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IMHO anything over 8 feet needs support. Check out the commercial quality antennas (I forget the brand names) they get better than average range. Same for cell phone antennas.

On the VHF antenna. Most important thing is a decent radio that's of recent vintage, a minimal number of perfect connections, good quality wire/wiring, and good quality recent antenna's. Then if you've got all that start thinking about going taller. Anything over about 9 feet needs support so depending on your craft its not always practical.

I'd look into Satellite Phones and SSB (single side band) radio's. Both are accepted methods for going the distance.

Cell phone antennas are "repeaters". It's the equivalent of standing in between two people who are nearly deaf and lost their voice, then parroting their conversation back & forth at a high volume.

"cell phone" service is limited by a certain distance, depending on the mode your carrier and phone supports (some modes and frequencies go further), and possibly power of signal at the towers (which is probably regulated by the FCC so all providers may use the same limited power)..

With RF (radio frequency, anything transmitted over the air or cable) technology there's a concept of upstream and downstream, upstream being what you transmit, downstream being what you receive..

Repeaters are designed to provide a better quality service in a non ideal building, and secondly on the road, not sure how much they really can add when you get completely outside of coverage due to the downstream part.. and the cheaper the repeater the poorer its gonna work. First one I pulled up was > $1000.. probably not practical for something that's only gonna add another 5 miles or so to your cell range (if that)..

When I say downstream part it's what the repeater "hears" from your perspective. If the signal is faint (what happens over a distance) it basically disappears into the inherent background noise like a drunk girl with big tits droning on about her boyfriend at the bar. The repeater probably beats a regular phone at "hearing" due to advanced filtering and a taller antenna but there's limit to it's capability due to signal strength and SNR (signal to noise ratio, which decreases as signal strength does).

Jon

Thanks for the feedback ( pun intended) guys...I am going to replace the antenna and wiring with fresh gear and was thinking getting a backup as well. My radios works OK now but I do not get 20 miles...probably about 1/2 that.

Yea, a sat phone is on my list. I've used them offshore on other peoples boats and they are wonderful. They are well worth the $ esp in an emergency.


I just wondered about these cell phone antennas and how they worked. I have no plans to get one unless they really did wonders.

Check this out. Google Sat phone store


Globalstar GSP1600 Satellite Phone
$399.00
SKU:
GSP-1600
Brand:
Globalstar

Thanks for the feedback ( pun intended) guys...I am going to replace the antenna and wiring with fresh gear and was thinking getting a backup as well. My radios works OK now but I do not get 20 miles...probably about 1/2 that.

Yea, a sat phone is on my list. I've used them offshore on other peoples boats and they are wonderful. They are well worth the $ esp in an emergency.


I just wondered about these cell phone antennas and how they worked. I have no plans to get one unless they really did wonders.

Yep agree, Sat Phone will work and is the most practical for occasional or emergency use.

Two radio's is the way to go. Had to put out a mayday a couple years ago with a boat filled to the gunnels with water from a rouge wave, picked up radio #1 and it was shot due to getting blasted with water, radio #2 worked and I got in contact with the coast guard.

Also VHF radios are the most likely electronic item to fail on a boat, between antenna's and radios they aren't all that reliable so having a backup is good, with two you can tell when one of them isn't up to snuff.

Jon

Had to put out a mayday a couple years ago with a boat filled to the gunnels with water from a rouge wave, picked up radio #1 and it was shot due to getting blasted with water, radio #2 worked and I got in contact with the coast guard.

Jon

Yikes! That sounds like a nightmare...not that you want to re-live it but I (and others I would guess) would like to hear the details on this. where,when what kind of boat did she sink etc
Feel free to go off topic....

Check this out. Google Sat phone store


Globalstar GSP1600 Satellite Phone
$399.00
SKU:
GSP-1600
Brand:
Globalstar

Globalstar has had huge problems with the reliability of their service. Most guys wouldn't touch them and use irridium instead.

I've heard guys that tried the cell phone antennas say they sucked and were a waste of money.

I have a new SH Quest radio and 8 ft Shakespeare galaxy antenna on my small cc and get great range. This galaxys outperformed digital antennas in a powerboat test. Also used a gold solderless connector by Shakespeare recommended by Dale on another board. He stated just changing this connector made a marginal performance to very good performance.

Off of block island I hear guys in the canyons sometimes, granted I can't transmit that far. Sounds like you just need new equipment and good connections. They have a fairly cheap device to check your equipment.

Panbo: The Marine Electronics Weblog: Shakespeare's ART-3, check your transmitting power! (http://www.panbo.com/archives/2006/04/shakespeares_art3_check_your_transmitting_power.ht ml)



For disaster time, losing electrical power, I have a floatable handheld with gps to call for help.

I have been looking at these (sat phones) for a couple years now....
Globalstar has been struggling with putting up new satellites for years...Most people I know who bought them gave up, threw them in the trash and went to iridium. If they ever get it fixed, they will have to give the phones away to re-attract the customer who is fed-up with them.

However, there is a newer alternative to consider...inmarsat . They use a different technology and from what I hear it sounds like it actually performs better than iridium in many cases. iridium works well but does drop calls from time to time.(but I like the design of irridum better) They use a lot of satellites, like 60, in a low orbit. inmarsat uses 3 sat's up very high that orbit around the equator. So this phone will not work very well if you are at the poles but in the lower lat's it works well as the sat's appear stationary because they are up so high (like 22000 mi.) They have very few dropped calls.

I will be getting either the inmarsat or the iridium this spring. I have not decided. I really only want it for the boat and so the plan is to get a charging cradle for it and get a plan that allows me to use it seasonally if I can. I think I will only use it a couple hundred minutes/year. The one nice thing about the inmarsat is that it has amazing battery life. I think they both do texting and can receive email/web stuff if you hook a computer to it but I only want to use it to make a few calls/texts when I am out of cell phone range or in an emergency.

I have used globalstar and the new iridium offshore. The iridium is way better but I would like to see an inmarsat before I buy anything. Inmarsat has very attractive pricing.

Actually I had an iridium phone when I was doing some classified work with the Service but we were using military sats for the comm and that's a whole different story. The iridium phones are the balls but they are expensive.