boat's auxiliary cellphone antenna seems to extend my range in some
places but makes little difference in others. How come? C.K., via
cell service issues are multiple, complex, and wicked hard to nail down.
Here are a few factoids I've picked up that might relate to your
cell areas are pretty tightly controlled. When the tower gives your phone
an electronic "handshake" every 30 seconds or so, it checks
your transmission power and drops service if it doesn't meet a pretty
high threshold (-65 DBi or less, to be technical). Putting a better antenna
higher up will help in fringe areas but won't in itself create more
transmit power. Analog systems are more forgiving, which may account for
the increased range you experienced in some places.
· Many marine
cell antennas do attempt to create more power, measured in DBs, by flattening
radiated transmissions toward the horizon. That works fine until your
boat starts rolling, which can cause what techies call "packet crashing"
and loss of service. Hence, more DBs do not necessarily produce better
results (and the correct balance is a bone of contention among the marine
cell service is getting worse in some areas because tower clusters are
fully populated and all their ranges are reduced. In other areas service
maps are occasionally more wishful than factual. I can testify that some
all-digital phones with "nationwide" service plans are useful
only as paperweights along the midcoast of Maine.
abound that some financially distressed cell providers are quietly reducing
the roaming choices available to their clients with free roaming plans.
I've spoken to a technically inclined fellow who swears that he's
now experiencing dead spots in places where his phone used to happily
roam to one of his provider's "partner" services.
the slight power of a modern cellphone, antenna placement and cable quality
are critical to performance. NMEA's new Installation Standard, discussed
in my column, has extensive guidelines and test procedures for antennas.
your question rather vaguely, but I do plan to test some of these auxiliary
marine cellphone antennas as well as the amplifiers that are increasingly
available. Hopefully I'll turn up some more definitive information.
a marine electronics question? Write to Electronics Q&A, Power
& Motoryacht, 260 Madison Ave., 8th Fl., New York, NY 10016. Fax:
(917) 256-2282. e-mail: PMYElectronics@primediamags.com.
No phone calls please.
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