Cellular Antennas
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Most chasers are currently using Internet data cards to gain access to a variety of products while in the field. Since much chasing undoubtedly takes place in more rural locales, the issue of poor signal quality will indubitable plague your chase at some point in time. Merely relying on the stock antenna with your data card is not the best solution; you can boost your signal reception with a relatively inexpensive external antenna.
The most important component to use for improving the signal reception of your cellular device is an external antenna. These external antennas can be used in conjunction with an inline signal amplifier or a repeater; it can also be connected directly to the data card itself.
Due to the higher frequency of cellular signals (800 MHz and 1900 MHz), your data card’s signal reception is very much a line of site communication, adversely affected by your presence within or near buildings, inside of motor vehicles, traversing through mountains, hills and valleys, and even by tree foliage. The quality of your reception will be determined by the presence of any obstructing factors, in addition to your distance from the nearest cellular tower.
The use of an external antenna is highly recommended, as a good antenna, positioned properly, will greatly improve your range of service. Any antenna that you choose to use should be mounted on the roof of the vehicle, preferably in the center, or on the rear of the vehicle. The biggest impact on the performance of your antenna is LOCATION, LOCATION, LOCATION!! A cellular antenna will best perform in the center of your vehicle’s roof.
Arguably the best performance comes from a permanently mounted, NMO style antenna. Not willing to turn your vehicle into a piece of swiss cheese to gain a little extra performance? Your next best option would be a trunk lip mount; various mounting styles and options are available to suit your vehicle.
If you’re still a bit worried about scratching your vehicle’s paint, you can opt for a magnetic mount cell antenna or even a glass mount cell antenna. Note: It is the author’s professional opinion that a glass mount antenna should be a last resort, due to potential performance issues with these antennas. Part of the antenna is mounted on the exterior of the vehicle’s window, while the other part of the antenna must be mounted inside of the vehicle, creating a separation between the two components. Performance of the antenna can thus be hampered by factors such as certain window tints, along with various types of automotive glass that contain RF-impeding metallic components.
Choosing An Antenna That’s Right For You
So how does one go about choosing the proper cell antenna? One caveat: more gain does not necessarily equate to superior performance! The job of the antenna is basically to concentrate any radiated RF energy into more channeled patterns s0 that a greater degree of RF power is being emanated from your antenna in a desired direction.
Antenna gain and effective angle of use is an inverse proportion: the higher the antenna’s gain, the lesser effective its angle of use becomes, simply because the higher gain antennas concentrate the signal output in a much more narrow direction. You can consult this diagram for a visual example of antenna gain vs. the concentration of the RF beamwidth.
A 1/4-wave (0 dB) ‘unity gain’ antenna effectively radiates most of its RF energy within a higher vertical plane, with the intended purpose being to reach sites that are located higher in altitude. This type of radiation pattern is most useful in a prenominal, upland or otherwise craggy terrain. They also perform well in metropolitan areas, where cell antennas are often located atop urban structures.
A 5/8 wave (3 dB) antenna or a given variety of a multi-element gain antenna will tend to radiate more energy toward the horizon compared to the unity gain, 1/4-wave models. These antennas will work just about as good as any on the market. This allows the user to connect with cell sites that are further apart and with fewer obstructions between the site and the user. For the chaser, these antennas tend to perform best on the open terrain of the plains and in other flat land areas. The radiation pattern of each antenna will vary, as it is decided by both the pattern and the number of elements on the antenna. Antennas with a greater number of elements will generally radiate closer to the horizon.
You will want a dual band antenna that covers both the 800 MHz and the 1900 MHz bands; 800 MHz has better range in the rural areas, most common to chasers, whereas the 1900 MHz bands tend to be more heavily used in metropolitan areas. Some of the new low profile cell antennas pack a powerful performance for a relatively low price; a personal favorite of the author is the Antenex/Laird Phantom line of cell antennas. Note that two different designs are pictured, and several of the antennas are multi-band, covering cell and wifi frequencies.
Once you’ve added an external antenna to your collection of chasing gear, should you still notice poor cellular performance in certain areas, you may wish to consider purchase of a cellular amplifier to boost your signal even further. However, the addition of a quality external antenna will negate the need for an amplifier in many cases. You will also need to consider that nearly all antennas will require the purchase of an additional cable and/or connector to make the antenna compatible for use with your data card.
Jesse L. Risley, K9JLR
