| Q: |
What is gain?
|
| A: |
Gain is defined as the compressing of the
vertical component of the antenna pattern, in effect causing the radiation pattern of the
antenna to reach out further toward a base station or cell site. |
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|
| Q: |
Why is gain important? |
| A: |
Gain is an important measure because certain
gain figures are better suited to particular usage environments. For strictly urban use, a
unity gain antenna is ideal. Because a unity gain antenna send the maximum signal above
the horizon at a high angle, it is excellent for areas where there are tall buildings and
for mountains as well. For people who live in
suburban or rural areas, 3 dBd gain is recommended. The 3dBd gain antenna concentrates the
maximum amount of signal at the horizon while maintaining a good high-angle signal. If you
are a cellular user, there is not need to buy an antenna stronger than 3 dBd gain as the
USA cellular infrastructure is designed for optimum performance using 3 dBd gain antennas.
If you are using a Land Mobile Radio (LMR) system and are
in a rural area, a 5dBd gain antenna is suggested as this will help to provide the maximum
amount of signal at the horizon with very little high-angle signal. |
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|
| Q: |
I see many other antenna
manufacturers offer antennas with higher gain than Antenna Specialists. Why is that? |
| A: |
Here is a case of "buyer be
careful". Gain can be expressed in many different ways. The two most common are dBd
and dBi. Gain expressed as dBd is a measure referenced to a halfwave dipole. The dBi
measure is referenced to a theoretical, dimensionless point source with a completely
spherical radiation pattern. Since it has no directivity, any real antenna without
excessive loss will provide some amount of gain when compared to the isotropic. Antenna
Specialists is now providing its gain measures in both dBd and dBi so buyers can have an
even basis of comparison. |
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|
| Q: |
I have a portable phone.
However, whenever I use it in my car, people say I sound fuzzy. I also drop more calls in
my car than walking down the street. Why? |
| A: |
Cellular and PCS phones operate on radio
frequency (RF) technology much the same as a car radio. The body of the car acts to block
the RF signal. Just as a good car radio still needs an external antenna or the radio
signal will be noisy cracked and broken, a cellular or PCS phone needs an external antenna
to provide better call quality. |
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|
| Q: |
What is the best mobile
antenna mount to buy? |
| A: |
There is no "best" mount. It all
depends on your use. The important thing is to ensure the whip extends above the roof line
of the vehicle. This will prevent the car from blocking, distorting or shading the signal
pattern of the antenna. |
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|
| Q: |
I don't want to install
an antenna as I use my phone in two different cars. Can I get by with only one antenna? |
| A: |
Sure. Either a window clip or magnet mount
antenna will meet your needs. Both are portable and may be moved from vehicle to vehicle.
Remember, though, a magnet mount antenna will adhere only to an iron/steel (OK through
paint) surface. |
|
|
| Q: |
I finally saved enough to
buy my first new car! No way do I want to drill a hole in it. What type of antenna can I
buy? |
| A: |
"On-Glass" antennas are easy to
install and do not diminish a vehicle's value by drilling a hole. Care must be taken
during installation to ensure that the antenna is mounted high up on the glass and not
over defogger wires or on reflective window tint and this could impede performance. |
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|
| Q: |
My new car has
Insta-Clear® windows and a fiber glass body. I still don't want to drill a
hole in my car but I can't use an "On-Glass" or magnet mount antenna. What can I
do? |
| A: |
You can have an elevated-feed trunk-lip
mount antenna installed. These antennas are designed to "elevate" the whip
electrically so that it is above the car roof. Elevated-feed antennas require no ground
plane so they may be used with fiber glass or plastic vehicles. |
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|
| Q: |
I have a pick-up truck
that I use for business. I really need to make sure I have good transmission and
reception. I know you said there is no "best" antenna but I need something that
will provide the "best" performance since my income depends on it! |
| A: |
Well, we did tell a small fib. The
"best" choice for optimum performance considerations is a roof mount antenna. At
this height the antenna is free from any vehicular obstruction. The roof also acts as a
ground plane for the antenna and actually becomes part of the antenna's electrical system.
Just remember, this antenna type does require drilling a hole in the vehicle. |
