Frequently Asked Questions/ Technical Information

We at E-mobile provide you as best, a solution as possible with all the testing, (former & continued) customer data and research we have compiled for some time now.

Many times selecting the right antenna for many people is a bit of a guessing game. There are so many variables that, it's difficult to determine what is going to work best in all of the locations you live, work and travel. Geographical layout, atmospheric conditions, obstructions and operating frequencies are just a few things that need be considered when choosing the right antenna for the job.

Sadly, many people have allowed the type of antenna they "like" to be the deciding factor on what they should purchase and not the "terrain" of the desired application. This includes hidden, portable, magnetic-mount on your car, glass mount, pole mount etc. The lack of conclusive information or knowledgeable advice on the part of many "cell phone dealers" today, have not made things any easier for the customer who needs to maintain a sure link of communication on a daily basis.

Many have tried several options before finding something that works for them while others are in locations that nothing will help. We have provided this information to help you understand a bit more why getting the "right tool for the job" is so necessary.

Many times just selecting an antenna that is convenient for the way you plan to use it (hidden, portable, magmount on your car, glass mount, pole mount etc.) works just fine. Most customers use the few tips we have here and select an antenna that works for them on the first try. A few customers have tried several options before finding something that works for them while others are in locations that nothing will help. We have provided this information to help you make an educated guess on what type of antenna might work for you.


1. What does Omni directional mean?
It means that the antenna will recieve signals from all possible directions for the mobile phone to work at its best. The original mobile phone stub antenna is nothing but an Omni antenna. (Followed by Image with Phone & Internal Stub Antenna)

2. What is dB gain?
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 the horizon. It is not the creation of power, but rather a simple refocusing of energy from all directions to a specific direction. Gain is measured in decibels (dB). Vertical antennas are in fact quite directional, except in the horizontal or azimuth plane.

3. What is the difference between dBd & dBi?
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 half wave 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. E-MOBILE antennas are all rated in dBd measurements.

4. What's the difference between 0db (unity), 3db, 6db gain?
0-dBd gain antenna radiates more energy higher in the vertical plane to reach radio communication sites that are located in higher places. Therefore they are more useful in mountainous and metropolitan areas with tall buildings. A 3-dBd gain antenna is the compromise in suburban and general settings. A 5-dBd gain antenna radiates more energy toward the horizon compared to the 0 and 3 dBd antennas to reach radio communication sites that are further apart and less obstructed. Therefore they are best used in deserts, plains, flatlands, and open farm areas.

5. My Mobile phone shows 1 or 2 bars but I still can't make a call. Why?
Although the phone shows some signal, it isn't strong enough to make a connection due to congestion in the network.

6. I can sometimes make a call but at other times I cannot connect at all. What do you recommend?
You might just need a little help. Try a Omni Power Antenna. Search for your phone's make and model (using the menu on the left) to see if one of these kits is available for your phone.

7. I live in a rural area and have to travel a Km. or two from home to be able to make a call on my phone, will an antenna help?
An antenna might help. If you're in an area with large hills or mountains, it's most likely nothing will help. But if the terrain is flatter, we would recommend a Omni Power Antenna or a Yagi antenna. The 6db is easier much easier to set up than the Yagi and most people get great results with one. Analog phone and service is your best bet in rural until more digital towers are installed. A Yagi antenna is your best bet in rural areas alongwith a very high pipe or a tower taking full advantage of height.

8. I used to be able to make calls with my old phone from home but now I can't make any with my new phone.
An Yagi Antenna will help, If your old phone was a GSM phone with a Stub Antenna and a External Antenna Adapter you have the advantage of an Antenna Adapter which would physically connect to your mobile phone without any signal losses. However, with the new trendy phones, most of which have internal antennas and no sockets for external antenna the only way out to connect an External Antenna is by using a Plastic Adapter which is not so efficient as compared to the older connector. Here the signal transmitted from the external antenna to the mobile phone is indirect and therefore only 80 to 90% efficiency is achieved.

9. I want something portable that will improve my signal strength and I can use in my home or office.
Try the Omni Power Antenna with the 2.5 metre cable.

10. I want an antenna that I can hide. What do you recommend?
In reality there are sticker Antennas available in the market costing from 50 to Rs. 500/- and improving the signal from 0 to 3% only, which is negligible as compared to our Omni Power Antenna giving 80 to 100% increase in signal strength. Our company believes in delivering real quality and performance and therefore we only deal in Omni & Yagi Antennas.

11. How do I connect an external antenna to my phone?
You can connect most phones to an external antenna by using an installable hands free kit that comes with an external antenna adapter. You can also purchase an external antenna adapter that allows you to connect the antenna directly to your phone. Some phones have an external antenna port. Other phones require that you remove your fixed antenna and insert an external antenna adapter to that port. Still other phones have no way to connect an external antenna to it at all. Read more here...

12. Can I improve my signal without connecting an external antenna to my phone?
Not to our knowledge.

13. Reception is poor inside my home or office. Can I use an antenna made to mounted on a car?
Yes, most cellular and digital antennas are manufactured for use on cars and trucks. The car or truck acts a ground plane for the antenna. To get the most from your antenna, you should supply a ground surface if using the antenna away from the vehicle. Many of our customers have had good success using these car antennas inside their home without a ground plane but we recommend providing a ground plane such as putting the antenna on top of a piece of metal (about 8 inches x 8 inches would be fine) and placing outside or near a window.

14. I'm in a basement with no windows. What are my options?
Some of our customers have seen increases in signal strength by just connecting an antenna to their phones and placing the antenna as high as possible. We would recommend getting it as close to the outside as possible without adding to the cable length.

15. I need an antenna with a 100 foot cable?
Adding to the cable length will greatly reduce the signal getting to your phone. As a general guide, you'll lose about .1db gain for each additional foot of cable with analog networks and .15db gain in digital. You'll also lose about .1db gain for each additional connector you use. You will compulsorily have to use the 15db High Gain Yagi antenna.

16. How does a glass mount antenna attach to the glass?
One portion of the antenna is glued to the outside of the glass and another is glued right behind it on the inside of the glass. The signal is transferred through the glass.

17. Since the glass mount antenna has to transfer the signal through the glass, does that mean it is not as powerful as the magnetic mount antenna?
No, the glass antennas are rated passing the signal through the glass.

18. I have window tint on my rear window. Will this interfere with the antenna?
If metal is used to tint the glass, it will interfere. Many professional installers will cut off a piece of the tint so that it does not interfere with the antenna.

19. Drill a hole… Not on my vehicle! What options do you have?
"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.
"Rear-Dash" is also another option, however performance losses will occur. "Magnetic-mount" This step-up, allows the easy placement and removal of your antenna on the rooftop of your vehicle. Very useful for multiple vehicle applications.

20. Where should I place my antenna?
In applying all the information provided for the maximum benefit of the radiating pattering of your antenna it would be wise to position the whip as vertically and as high as possible.

  • If the antenna is tilted, some of the signal will be wasted because it will be directed up to the sky or into the ground.
  • If the antenna is much lower than the vehicle's roof, the signal will be blocked and the radiating pattern will be distorted.
  • E-mobile customers may direct any further questions to:

    21. Can I use a Vehicle Magnetic Mount antenna anywhere else?
    Yes, most magnetic mount cellular antennas are manufactured for use on vehicles, as the roof of the vehicle acts a ground plane for the antenna. However to get the most from your magnetic mount antenna, you should place it on a metal ground surface when using the antenna away from the vehicle. These antennas work great indoors once a sufficient ground plane is provided, such as placing the antenna on a filing cabinet or on a piece of metal (about 8 inches x 8 inches) and placing it outside or near a window.

    Some Final Observations
    You can experience choppiness in the audio even when your signal indicator is reading 2 or 3 bars.

    If you are presently in the market for a new phone, our advise to you is to ignore the hype surrounding the technologies and look at service provider instead. Judge each with an eye to price, phone choice, coverage, and reputation. Technology should play a very small roll in your choice, as the products we carry at E-mobile will more than likely overcome any of those problems. If you follow this advice, you'll probably be much happier with the phone and service you inevitably wind up with.

    General Information
    External Antennas connected to portable cell phones, (CDMA and GSM) greatly increase signal output, or propagation to the cell site tower. The improvements in signal pattern, strength, and effective range can be dramatic. Using an external antenna adapter will allow connection to any external antenna. The portable phone can be connected to an antenna on top of the car, SUV or even a filing cabinet at the office. Or connect to a marine antenna up 20 feet on the boat. Or connect to a directional antenna outside the home or factory to beam to a distant cell site. Plus, battery power is extended and radiation is kept away from the user. Below, in various paragraphs are the details wanted by users so they can also improve their antenna performance.

    Most phones on the market today may have a very well designed antenna on top of them but they are usually performing with a gain of -3 to as much as -15, that's negative 3 to 15 dBd using a dipole or quarter wave as rough reference point. The lower number could be the phone as a stand alone item and the highest negative numbers come when the phone is in your hand and one inch from your head. Not to mention the radiation pattern which is far from omni-directional, PLUS the polarization is not vertical, which is what the cell site prefers. And don't forget, on top of all that you may be inside a metal roofed car!

    As we can see, signal propagation off the top of a portable phone can be pretty bad. Fortunately though most users are working well with on-phone antennas because of the supreme cellular coverage enjoyed in the US and some other highly developed countries. Today, cell sites are covering the land and providing a nice blanket of signal coverage. BUT, there are lots of exceptions to this good coverage.

    The antenna placed away from the phone and in the clear will provide enough performance to increase usable distance between 2 and 50 miles. Small 3" tall magnetic (0dB gain) antennas are at the low end of this distance estimate and 8-element Yagi directional (10dBd) can be at the high end. See the Yagi tech info page for more info on those. While the Yagi or Panel antennas are for fixed locations and provide terrific gain in one direction, the popular external antenna is a magnetic based or glass mounted antenna on the car. This type will be address here.

    We would never really state an exact distance increase because it is all very dependent on conditions that are changing constantly. For example cell-site tower distance, site antenna height, design, type of terrain and placement and efficiency of the external antenna. We can safely say that, the external antenna will provide a vertically polarized, omni-directional signal at 0 (zero or unity) gain up to 7dBi (6dBd) which will be a noticeable and effective signal increase. Depending on the phone and what antenna is used outside the car, signal improvement should be on the order of 6 to 20dB less approximately 1 dB for cable losses to the antenna. This equals, anywhere from triple to 5 times the power (on the horizon) that was being radiated by the phone-top antenna!

    Use of an external antenna will keep the signal radiation away from you. Instead of radiation 1" from your head (ruining the signal pattern) you will be sending your signal out to where it works best. This also addresses the safety concerns of radiation so close to the head.

    Use of the external antenna can greatly increase battery life! Your phone has 7 output power steps. It is instructed by the cell site how much power to put out between approximately 1/20th of a watt to the full power 6/10ths of a watt. If you are using the external antenna in a moderate to good signal coverage area, your phone will power down because of the increased antenna efficiency.

    The best way to get the signal out of the portable phones is by using the manufacturer's "Car Kit" or "Hands Free" kit selecting the model with RF out or RF interface for antennas. Sometimes the RF version costs substantially more or is not offered, or the user wants total freedom instead of placing the phone in a cradle or holder. carries cables (external antenna adapters) which can connect directly to the phone. These cables, approx. 8" - 24" thin cable where one end plugs into the phone's antenna and the other end provides a popular coaxial connector (TNC, FME, Mini-UHF are examples) receptacle to allow a thicker, lower loss cable going to the cellular antenna, to be connected. The thinner 1/8" (RG-174) cable near the phone allows free movement and is not as restrictive as the 3/16" (RG-58) cable supplied with most antennas.

    Some phones have the tiny "coaxial" jack as part of the multi-pin connector block inside the bottom of the phone. Our connector will plug into that and use only the coaxial pin while the other pins are blank and not used. In this case you would not be able to connect another one there to access audio, charging or data pins. For some phones we offer a combination charging/antenna plug as a unit. But remember, external antenna usually means longer battery life due to lower RF output in moderate to good coverage areas. Phones in this category are the families of Nokia 2120/2160 etc., Mot StarTAC, Elite, Ericsson 738, Sony 100 etc.

    The other type of output on phones places the RF jack all alone usually on the back near the top but it can be on the bottom or side near the bottom. This stand-alone RF jack will not interfere with the multi-pin at the bottom. Examples of this are the Ericsson 300 or 600 (non retractable antenna types) and the Nokia 6100/5100 series.

    Read our Recommendations page for more information on the cellular phone antenna that's right for your situation.
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