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Most hand held cel phones have a max transmit power of 0.6 Watts. The same, or less, is true for laptop mobile broadband cards and for 2G & 3G devices like the Blackberry and iPhone. A dual band 'booster' amplifier can increase the transmit output to 3 Watts. That's a 500% increase in ability to 'reach out' with good, clear signal. Dual band is critical as cel usually happens in the 800-1000 Mhz band as does 2G data. 3G data happens in the 1200-1950 Mhz band and defaults to 800-1000Mhz when only that is available.

The antenna of a current hand held phone is about 6 ft/1.8 m, or less, above the water's surface when in use. At this height the phone's visible horizon is only 3 mi/4.8 km away. Height above water matters for ability to 'see' and 'reach ou' to cel towers on shore. A high gain antenna, 5db or greater, also better squeezes down and 'pushes out' the signal to better 'reach' any cel towers the phone can 'see'.

The correct antenna, mounted as high as possible (masthead) 60 ft/18 m above the water also greatly enhances the ability to RECEIVE as well as transmit voice and data as the antenna is able to 'see' a visible horizon over 10 mi/16 km away.

A cel tower only 200 ft/ 61m tall that's on shore only 150 ft/46 m above water level 'sees' a visible horizon over 28 mi/45 km away.

Thus the masthead external antenna and the tower can 'see' each other from over 38 mi/61 km apart.

FYI . . .
Cel tower heights in most of eastern Canada range from 240-270 ft /73-82 m
Average cel tower height in the U.S. is 300 ft /91 m.


An onboard 'system' . . .
1. external high gain antenna is hardwired from masthead to the amp
2. best quality, most shielded, and lowest loss coax connecting cable
2. dual band amp is hardwired to an onboard 'local area' antenna
3. voice or data device communicates to and through the amp wirelessly via the onboard antenna


A high gain antenna can quickly lose range to port and starboard the more a boat heels when sailing. Fore and aft range will remain strong even when heeled, except in a very heavy seaway when the boat is pitching significantly.


So far . . . best affordable consumer equipment found in this field is from Wilson Electronics :

external antenna
301101 - US $40

suitable dual band amps . . .
811210 - US $160
801201 - US $280 - provides ability to get up to 100ft/30m from amp and still use your device

internal antenna . . .
301127 - US $20

internal antenna w. 10'/3m device to amp cable . . .
310143 - US $26

'System' results should be ability to usually reach about 40 mi/64 km to a tower onshore.


Anyone know any better gear?

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