Cordless phone buying guide

Which system?

There are different systems that cordless phones use for the wireless communication between handset and base. Probably the most common is DECT and its derivatives.

The DECT system was designed in Europe and is used by several manufacturers. The phones operate in a reserved 1.8GHz frequency band, so they don't suffer from interference from other wireless devices like WiFi networks. They are designed to have a range of around 50 metres.

We think the best system is DECT-GAP. This stands for – take a deep breath – Digital Enhanced Cordless Telecommunications, Generic Access Profile-compliant. The beauty of these phones is you can mix and match handsets and base stations of different makes and models, You can also transfer calls between handsets, and handsets can be registered to more than one base station. Not all DECT phones are GAP-compliant, however.

XDECT is a proprietary (Uniden) version of DECT that claims greater range.

5.8GHz phones use proprietary frequency-hopping technology. These phones are not related to DECT and often have a shorter range – especially through building obstacles.

A warning about DECT 6.0 imports
Because the 1.8GHz frequency band is used for other things in the US and Canada, the system was modified to use 1.9GHz in North America and was renamed DECT 6.0.

However, one of our mobile phone networks uses the 1.9GHz band – and privately imported DECT 6.0 systems can (and have) interfered with our mobile phone system.

Any DECT device you buy locally shouldn’t be a problem. But don’t use any DECT 6.0 device you’ve purchased overseas or through an overseas website.

Other factors

Type of batteries
We like standard-sized "AAA" (NiMH) rechargeable batteries. When the batteries finally fail, replacements are available in most supermarkets and other outlets. With a custom battery-pack, a replacement can be difficult to find – and possibly more expensive.

Extended range
If you have more than one floor or want to extend the range to cover a workshop or out into the garden, then a repeater could be useful. A repeater receives the signal, then amplifies and re-transmits it. Placing the repeater at a suitable distance from the base station makes it theoretically possible to double the phone’s usual range.

Talk time
Most handsets give between 10 and 20 hours of talk time. That's plenty, but make sure you replace the phone in the base station after a long chat. Standby time can be up to a fortnight or so.

Phone size
Small phones are easy to carry around, but larger models are more comfortable to use, especially for longer conversations.

Ease of use
Look for good-sized buttons, preferably backlit, with clear labels. Watch out for numbers made hard to read by a lack of contrast (for example, grey numbers on a grey background).

Try the handset to ensure it's not too heavy, is comfortable to hold, and fits well against your ear. Physical design is especially important for elderly or disabled users.

Electromagnetic radiation
Is radiation an issue for cordless phones? To date no clear evidence of a problem for mobiles or cordless phones has emerged. If you still want to limit your risk, use a wired phone for long conversations.

Interference
To avoid interference we recommend DECT phones. The frequencies they operate on are not used by other products and so they avoid interference from wireless networks, computers, home security systems and domestic appliances.

Analogue phones

Analogue models have been superseded by digital. They have fewer features than digital models, you won't get advanced options like multiple handsets, and privacy isn't guaranteed.

Tip: Cordless phones require mains power to work. Always keep an inexpensive corded phone for use if there's a power cut.

Features to consider

Depending on your needs, these features may be useful.

• Answering machine: The extra cost of a model with built-in answering machine can be recouped within a year compared with the cost of paying a phone company for voicemail.
• Message indicator light: If you use your phone company's message service, a message light is useful.

  

• Bluetooth connectivity: Lets you connect up to two Bluetooth-equipped mobiles to your cordless system – so you can use your mobile to make and take landline calls as long as it’s within Bluetooth range of the base-station.
• Speaker phone: This lets you use the phone hands-free - a good feature when you're hands-on in the kitchen. It's also handy if you've got a crowd who want to listen.
• Multiple handset option: Lets you register other handsets to the base station, though only one outside call can be made at a time. Multiple handsets can also be used as intercoms. With GAP-compliant DECT phones the handsets can be of different makes (see the 'Choosing the right phone' for more about DECT-GAP).

Sometimes you can get a "pack" with at least one extra handset for not much more than you'll pay for a single phone. If you have a two-storey house – or a home office or work area – having more than one phone can be handy.

• Corded phones: A corded phone in the base station lets you make calls during a power cut – useful if you don’t already have another corded phone or a mobile.
• Caller ID: Lets you see the phone number of the caller, before you answer. The caller's name can also be displayed, if their details are in the phone's directory.
• Headset port: Allows wearing a headset as another form of hands-free phoning.
• Baby monitor: Allows monitoring of sounds in another room, such as a baby crying.
• Adaptors: Most models come with a low-voltage, plug-in power adaptor. A safety approval number on the adaptor shows compliance with electrical safety requirements.
• Conversation recording: Digitally records conversation – especially useful for taking notes during phone meetings.
• Emergency alert: Emergency alert pendants can be worn around the neck, arm or waistband and are small enough to be unobtrusive. They're connected to the cordless phone’s base station and at the push of a button will call up to 5 user-programmed numbers one after the other until the call is answered. This system would be useful for anybody who might require emergency assistance at any time. It works as long as the user is within range of the base station – that’s usually inside the home and (maybe) in the garden.
• Smartphones: The Panasonic KX-PRW120 lets you connect up to 4 smartphones using your WiFi. This lets you make and receive landline calls from the connected smartphone(s).

Vision or hearing assistance

Some phones offer features for vision or hearing impairment, including:

• large buttons and display screens
• extra-loud audio
• hearing-aid compatibility
• slow replay of recorded messages.

Fibre and power outages

We’ve noted which cordless phone models still work when there’s a power outage. However, if you have changed over to fibre-only broadband there’s another issue - fibre services require mains power to operate.

This means when the power is out, even if your phone can work in a blackout, the phone line itself may stop working. You can solve this with a battery backup in your home. For more information about this, contact your internet provider.

Do you need a landline?

More people are using mobile phones instead of a landline. Spark said there has been a year-on-year decline of 15 to 20% in the number of landline calling minutes used. But there are advantages to landlines: free local calls; hearing aid compatibility; and a free answering machine.

You could bite the bullet and ditch your phone line. Most mobile phone plans have increasingly large amounts of free minutes.

The ultra-fast broadband (UFB, aka fibre) roll-out means the clock is ticking. When you upgrade to UFB, you’ll need to decide what to do with your landline. To keep using your current phones after your fibre installation, you’ll need to get integrated wiring. This may cost more, but you’ll get to keep your phone number. Note this works over fibre, not the old copper lines, so your phone won’t work during a power cut.

Some monitored home alarm systems and medical alert devices require copper lines, so you need to check this before installation and either upgrade the alarm system to a fibre-enabled version or pay extra to keep the existing copper line connected. Generally, upgrading is your best option.

Or you could bite the bullet and ditch your phone line. Most mobile phone plans have increasingly large amounts of free minutes — a Spark $19 pre-pay plan has the same amount of free New Zealand-only minutes (100) as a $60 pay-monthly plan did in 2012. There’s also free video-calling programs, such as Skype. At the very least, you won’t get telemarketers bothering you during dinner.