Quick Review, Teardown: Uniden DECT 1015 Cordless Phone

Since I’ve been playing around recently with running my own Asterisk server at home and having many ATAs to create internal extensions to create virtual POTS lines to play with modems and other telephony devices, I desperately needed some nice cordless phones to go with it. Just as luck would have it, it seems the cordless phone market is pretty saturated and probably slowly shrinking, so a basic single handset DECT unit can be had for anywhere from AU$20, which is miles better (sound quality and security wise) than the 30Mhz analog NFM unit we still have and still use from time to time.

Which got me thinking … just what is inside this $20 unit?

The Unit

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The unit in question is Uniden’s DECT 1015. Uniden has been known to confuse users with their branding and this unit is no different. I love how the front says “DECT Digital Technology Phone System,” where DECT actually stands for Digital Enhanced Cordless Telecommunications.

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The unit is emblazoned with the DECT 6.0 logo on the box, as well as on the unit, but guess what? This unit IS NOT DECT 6.0 at all! A close read shows that it is derived from the cutting edge American DECT 6.0 technology. In reality, DECT 6.0 is a marketing term for the frequency-shifted European DECT to meet US bandplan requirements, and thus DECT 6.0 is just DECT running at 1920-1930Mhz with reduced power output. European DECT, which is the only flavour we are permitted to use runs in 1880-1900Mhz band. I did check the unit with a spectrum analyzer and I can confirm it is just plain DECT.

The only reason they like to have the 6.0 on the box is that consumers often associate higher numbers with better products, and they wanted to have an edge over the 5.8Ghz cordless phones … but hey, this is an adaptation of an inferior adaptation of the original for Australian and New Zealand conditions. I’m sure if that was written on the box it would sell like hotcakes!

Uniden’s been guilty of this sort of misinformation before with their own WDECT handsets (which I also own one of) which are not DECT at all as they operate on 2.4Ghz and trample over Wi-Fi transmissions. Worse still, as it’s not DECT, it is not GAP capable and thus cannot be interoperated with other DECT equipment. But consumers see the DECT in WDECT and don’t know any better …

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2016022415512539Inside, you get a base which is designed for wall hanging as well as sitting on a desk with specially recessed charging terminals to keep them clean. All standard features on late-model cordless phones.

Of course, you also get the handset itself, with hard plastic keys and a backlit LCD display. There is an LED to indicate charging, and a ringer on the rear of the unit.

The unit supports caller ID if your line has the feature, and intercom calls if you have multiple handsets registered to the same base (up to six).

The speaker can go quite loud and exceeds NZ Telecom standards. It also has a T-coil option which makes it better for those with hearing aids but can compromise battery life.

Unfortunately, there is no fancy LED backlit keypad and the hard plastic keys are a little slippery and provide less tactile feedback than I am used to.

The design of the handset also suffers from a somewhat critical flaw, in that it is shaped fatter at the bottom tapering to a very thin shape at the top. This makes it quite difficult to securely hold inbetween your ear and shoulder for “hands free” operation.

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Also of note is that there is no external headset options for this particular model – but what can you expect for AU$20?

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Also included is a power adapter, although in my multi-unit purchase, it seems that there are (at least) two variants, one being slightly more efficient (rated with an efficiency category of V, versus IV) than the other. The dates indicate that these units were made in Week 47 of 2013, making this stock over two years old just “sitting” in the distribution channel.

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It also comes with a basic two-conductor telephone cable and a 2.4v 300mAh Ni-MH rechargeable battery, code BT-694m.

Teardown

The fun part, when it is cheap, is that I don’t have any fears about taking it apart, voiding the warranty and potentially breaking it on day 1. The unit itself is Made in Vietnam and is fairly light, so I suspect a large amount of integration exists and the number of components inside is very few. Lets see if that’s correct by starting with the base.

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The only things holding the base together is two screws next to the square feet. Once they are removed, the unit can be pried apart.

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From the underside, we can see that the unit is comprised of mostly a single PCB, with a radio module attached to it on the rear. A few debug terminals are seen at the botton, marked VRDP GND URX and UTX, which is likely to be a serial interface of some sort maybe for programming base firmware/numbers. A printed antenna can be seen at the top area, but there is also a wire antenna on the side. Once the screw is removed, the PCB can be freed.

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Once freed, we can see the protruding wire antenna which is basically vertically oriented inside the case. This provides both antenna diversity and polarity diversity ensuring good reception if you should wish to go from “standing up” with the phone to “lying down”.

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The top side has the find button and very few other components bar a gob topped chip on a PCB carrier module soldered to the PCB. This is the first time I’ve seen something like this – namely a gob top on a carrier with engraving on it. A version label claims it is V10.34. The board has many vias placed around it to maintain good ground plane impedance and shielding.

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With the label removed, the chip is marked 19912D2 041213V 2389. Given how few components there are, it seems it is a highly integrated design to the point there isn’t even a discrete hybrid transformer of the classic sort.

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The handset is a similar story, with the exception that the programming terminals are exposed through a hole in the casing. Two screws hold it together, and once removed, the casing can be pried apart.

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Like the base, it too also consists of a gob-topped chip (v10.24) on a PCB carrier and an RF module on a PCB soldered to a main PCB. Here we can see the rear ringer speaker connected to the board by soldered wires. The antenna is a printed trace on the PCB near the earpiece, but it doesn’t seem like there is any antenna diversity on the handset which is a bit of a shame. Again, one screw secures the PCB to the casing.

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Underneath the label, the chip is marked differently to the one in the base – this is marked 19852D2 131213V 2418. It’s likely where all the phone’s features and crypto power is housed.

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On the other side, we can see that the hard plastic keys are just a cover over the rubberized membrane style of keys used in remote controls. The membrane is made to surround the mic as well to minimise echo from the audio from the speaker getting picked up by the mic.

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Underneath we find the keypad traces which are coated in some sort of carbon black (?) as opposed to remaining metallic which can oxidise on exposure to moisture.

General Comments

On the whole, the unit does work quite well with a tested range easily reaching 40m through the house to the neighbours’ house and slightly beyond. The audio quality is very acceptable, and relatively clear, although the handset can get a little too loud even at the minimum setting. Having just two ring-tones to choose from is a little annoying when you’ve got more than two units and two lines, and the menu response speed for the redial option is quite slow (as it contacts the base to retrieve the redial information).

While the units are probably GAP compliant, I did not find any information on how to pair them with other bases. In fact, you can pair multiple units with the one base to share the same line and have intercom calling, but the manual does not tell you how. This may be because they want you to buy the (potentially) more expensive multi-handset packs, but you can just pair a handset from another pack into your existing set-up and use the original base as a “dumb” charging stand.

To do this, you can follow these instructions:

  • Press and hold END and # until the <SYSTEM RESET> menu comes up.
  • Choose BaseUnavailable to deregister a handset belonging to a new base that hasn’t been powered up
  • Place the handset into the base you wish to register with when not in a call.
  • Wait until the registration is complete (20 seconds or so).
  • You can choose to Deregister HS to remove a handset already registered to a base you are connected to (e.g. you joined another two handsets and you suddenly decide that one should be removed to go into its own independent system).

I also discovered that you can retrieve some information about the handset and base (firmware revision?) numbers by holding the END button for 5 seconds, although the format of these numbers are not known.

When the handset was tested for endurance, it did exceed the claimed 7 hours of talk time, reaching 8 hours before shutting down completely. This is rather remarkable as it implies an operating power of just 90mW (considering the batteries are 2.4v 300mAh = 0.72Wh). Even with larger cells, the older analog phones rarely reached more than three hours and with a shorter range.

As with any handset, there was some level of echo especially at louder volumes, but not more than any other average handset.

Conclusion

The landline phone is slowly dying, and sales of corded and cordless phones are probably on their way down. As a result, we have cheap products which offer all the basics and more, and perform decently well. This Uniden is cheap and no-frills but still has caller ID, intercom and phonebook features. The audio is clear and quite loud, and the battery life is more than adequate. It makes you wonder why you’d even buy a replacement battery for many existing units given this whole unit costs about as much as a replacement battery.

As expected, its internals are simple and integrated, leading to few potentials for component scavenging and reuse. It does however imply potentially better reliability.

I suppose one thing it doesn’t have is an answering machine … but who needs that … and who expects that in a unit for AU$20?

About lui_gough

I'm a bit of a nut for electronics, computing, photography, radio, satellite and other technical hobbies. Click for more about me!
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