FAQs

+ I have seen these stickers you put on the back of the mobile phone to improve coverage - do they work?

(Yeah right - this has to be a good add for a Tui bill board.) Sorry but we have to be careful here as to what we say as we have seen these on-line too. What is even worse is they claim to have a "testimonial' page detailing satisfied customers! So lets answer this diplomatically. If a sticker you placed on the back of your phone for <$5 data-preserve-html-node="true" really improved coverage don't you think the manufacturers of the phones would include such a sticker? We are not going to write anymore here, but please be warned these stickers DO NOT WORK and add no value AT ALL to improving coverage to your mobile phone.

+ What are the benefits of external antennas?

External antennas provide better call quality, less dropped calls, provide your phone with much improved coverage range, and remove RF (radio frequency) emissions away from your body.

+ Can my phone connect to an external antenna? And can I damage my phone when connected?

We can improve coverage to all phones and modem devices with an external antenna. Ideally the best connection for optimum performance improvement is choosing a phone or data card that has a direct connection. If your phone or data card does not have a direct connection then you can use a passive connection. One of our most popular products is our passive repeaters. When connecting your phone or data card to an external antenna with a direct plug-in connection you must use caution. Some phone and data card manufacturers do not expect people to regularly connect and disconnect their phone or data card to an external antenna. As such you must make sure you plug the connection on "squarely" to the connection point. Do not pull on the cable or drop the device when connected. Any excessive force on the connection point can be damaging to both the device and the data card. It is therefore recommended that when connecting a phone to an external antenna you use a hands free ear piece and operate the phone while it is lying down on a desk or centre console. Another useful tip is if you are using a USB datacard, connect the data card to your computer by way of a small USB lead (many USB datacards are supplied with such leads). This has the advantage that if you move your computer abruptly the cable will tension first rather than pulling the datacard out of the computer by the antenna adaptor cable. Cellutronics takes no responsibility or liability if phones, data cards, or adaptor cables becoming damaged.

+ How do I connect an external antenna to my phone?

This can by done using an antenna adaptor cable. The adaptor cable is a cable which has a special connector on it which is specific to your handset. It plugs into your phone and then connects to the external antenna. See → Connection types for Mobile phones/data cards. Or use a passive connection adaptor cable.

+ I have intermittent coverage outside my home and no coverage inside. Do you think an external antenna will fix my problem and if so which antenna should I use?

Yes, an external antenna will fix your problem so you can receive reliable good quality coverage inside your home. We would recommend a Yagi antenna, starting at the AY9-12 right up to the AY12-12, or AY15-10 (AY15-10 if you want to make sure you cover all services available). Most NZ rural locations are served by 800/900 MHz so AY9-12 or AY12-12 are best. However, both Telecom and Vodafone are expanding the use of 2100MHz from the main cities. So in peak demand (heavy customer usage) your device maybe capable of switching to 2100MHz). If you are not sure please email us and we can advise further sales@cellutronics.co.nz

+ What is a Yagi antenna and should I use the Yagi AY9-12, AY12-12, or AY15-10?

The name "Yagi" is given to this antenna from one of the Japanese inventors. It is antenna which has a series of 'Elements' connected to a 'Boom'. Some people refer to them as looking like a fish skeleton. Your TV antenna is similar to a Yagi, except the TV antenna is wider as it operates on a lower RF (radio frequency).

The AY9-12 Yagi antenna is our most popular high gain antenna. It is intended for most users who want a high gain antenna at an economical price. The AY12-12 is a stainless steel antenna and is long at 1.5m in length. The AY12-12 has even higher performance than the AY9-12 . The AY12-12 is recommended for user's wanting maximum coverage, or customers who have poor to no coverage at their house or office location.

The AY15-10 is a dual band antenna or wideband antenna 700-2700MHz. Choose this antenna if you know your device and location is using 800/900MHz and 2100MHZ. Not sure? No problem just email us and we can advise sales@cellutronics.co.nz

+ What does the term 'Gain' refer to?

(Be careful - use high gain antennas for stationary generally line-of-site applications, however for moving locations such as vehicles or applications where you don't have line-of-site to the base station you need low gain antennas.)

Gain is the term used to measure the effectiveness of an antenna in one direction. It is usually measured in decibels (dB). The higher the antenna gain the higher the intensity (or ability) of the antenna to receive and transmit a signal in one direction. For example consider a light bulb in a house. The light bulb radiates light waves generally in all directions (omni-directional). This is ideal for lighting up a room.

Now consider the light beam from a lighthouse. The light from a lighthouse is intense and directional. It needs to go as far as it can to warn ships from hitting rocks. You can think of the lighthouse as having high gain. This is similar to a Yagi antenna. The lightbulb in the house you can then think of as having lower gain. They both have their applications. For example if you want an antenna for a vehicle you will require a low gain omni-directional so you can always get coverage as the vehicle changes direction. However, if you have a stationary object such as a house you can install a directional antenna such as a Yagi antenna. The Yagi antenna will point towards the strongest signal source (usually the closest cell-site) and direct the mobile phones RF energy (such as a light house) in that direction.

+ Can I improve coverage to my phone without connecting an external antenna to my phone?

Yes. You can use a repeater. We have 2 types of repeaters, that we refer to as passive and active repeaters. Passive repeaters are the most popular due to them being less than half the cost of an active repeater and work on all NZ Telcos at once. Whereas activer repeaters maybe more expensive and Telco specific (either Spark, Skinny or 2degrees) but they do have the advantage that you can walk around your house with as many devices as once and not have to place your device (smartphone of wifi/hotspot) on the passive radiator. Go to this page to learn about repeaters.

+ I have lots of questions about repeaters? Are they legal? Which ones cause interference? Can I buy one from Trademe? How do they cause interference?

We have a whole new section on this. Please refer to Repeater Help

+ I have installed a AY12-12 on my roof and it has now given me excellent coverage. I would like to connect a second phone to this antenna. Can this be done and if so can we use both mobile-phones at the same time?

Yes, by installing a mobile phone splitter you can have two mobile phones connected to one antenna and the mobile phones can be used at the same time. Please be sure you use a splitter which has higher directivity such as the Cellutronics 'SPL-2-50NF', otherwise the phones will interfere with each other.

+ I would like to purchase a Yagi antenna for my home. Can I install this myself?

Yes you can install the antenna yourself. The antenna kit comes complete with installation instructions. You will need to have access to your roof and follow the instructions to align the antenna in the best direction to give maximum coverage. If you are not comfortable in installing the antenna yourself we recommend employing the services of your local TV antenna installer. They will have the necessary equipment and training to get to your roof and will know how to align the antenna.

+ Why is this antenna small? And shouldn't I install a large long antenna?

There are two main factors which determine the length of the antenna. Firstly frequency. The higher the frequency the smaller the antenna. So for example a TV antenna or car radio antenna, the frequencies are lower, generally VHF (very high frequency) antennas compared to mobile phones which operate at UHF (ultra high frequency) and above. The second reason is if you stack mulitiple dipoles on top of one another the antenna becomes longer and the antenna is said to have greater 'gain'. People then interpret higher gain as having greater coverage. This is true if your location is fixed, such in a house. In this case you can install one of our Yagi antennas and point this at the far away cell site and get fantastic results. But high gain antennas become a downfall for a moving mobile user, which is the case for a vehicle. What happens is a vehicle will move in and out of line-of-site (LOS) to the base station (cell site). When the vehicle moves out of LOS the antenna picks-up multipath signals which are reflected off buildings, hills, roads etc. These radio paths will hit the antenna at all sorts of azimuths (directions), so it is important that your vehicle antenna can 'see' these signals from everwhere and not just in the main horizontal beamwidth of the antenna. Remember to achieve gain you are directing the pattern to be stronger in one direction, and to achieve this you are taking the signal away from another direction.

A good analogy is to consider the way vehicle driving lights work. The way the headlight is made is it has a small bulb incased in a highly reflective casing which concentrates the light waves in one direction. If you imagine yourself standing in front of an on-coming vehicle at night with it's lights pointing towards you, you should see the vehicle approaching you from very far away. So this is similar to installing a Yagi antenna to your house and pointing the Yagi to the Base Station. If however you are behind the vehicle and the vehicle is reversing towards you, you will not see the vehicle until it is really close to you (ignore the vehicles tail lights). So the point here is a high gain antenna or headlight is directional, and the problem with a high gain antenna on your vehicle is sometimes you will be in front of the cell site, sometimes it will be behind you, and sometimes you will be above or below it as is the case when you are travelling over hills.

So if this all sounds too long winded and complicated, just remember two things. For fixed non-moving locations such as a house, office use a high gain Yagi antenna. For any moving locations such as vehicle or boat use a low gain omnidirectional atenna, such as the AM1-5 and AM1-6 mag mounts, AFM1-3 vehicle mount, and AFM1-5 marine antenna