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(More customer reviews)Hello,
I am a scientist in the field of Microwave/RF circuits and systems. I considered several but finally chose the Jabra A210 along with the BT250 Jabra headset. This review is for both items together.
A few things to note:
1) swithcing on and off is not very intuitive for the BT250, you have to hold down the power button for "n" number of seconds, the lights will flash in a certain pre-ordained sequence, but if you do hold down the power button more than what is required (this is sketchy), then the appliances enter set up mode, and the pairing between the adapter and the headset might be lost. The A210 is paired by means of a stylus pressing down a depressed switch on the body of the unit. So its pairing is not affected by the power button. BUT this set (headset and the adapter) have 8 hours talk time and 240 hours standby time (as per manufacturer's claim), even if it performs up to 80% of the reported claim, you wont have to mess around too much with the power switch. You can comfortably use it during the day and come home at night and recharge the set.
2) Quality of sent and received signals. Please note: The jabra A210 has a pin which can be put in to 3 settings. Setting # 1 is for motorola phones, Setting # 3 for all other phones and Setting # 2 is for when you feel discomfort in setting # 1 or # 3. I have a LG VX 6100 NON-BLUETOOTH phone from verizon. I tested the settings extensively by calling a friend. (Thanks Guddu.) I tried setting # 1, there were 2 noticeable problems: (a) My friend complained that the volume of my voice was low, but the clarity was good.
(b) I could not use the button on the head set to connect and disconnect calls.
But I must mention, I could receive my friend's voice in absolutely loud and clear tones.
Both the problems were alleviated when I used setting # 3 on the adapter. In fact, when I started using setting # 3, my friend complained that my voice was too loud! There werent any issues related to clarity.
3) Range: The manufacturer claims this to have a range of 10 meters (30 feet). But at the same time, in its manual, it is written that if there are objects in the wireless signal path between the adapter and the headset, the sound quality will suffer.
Now we have to consider 2 trade offs for every RF design. (a) power (b) size. We all want the smallest devices with maximum power and range. Well physics and electronics sharply put us back in our places. If you want greater range, you need to put out signal with great field strength. That needs higher battery consumption, high efficiency non linear amplifiers and large antennas. Microstrip patch antennas (generally used for their low profiles and small size) resonate to a particular frequency if their length is correctly defined. But with design modifications, this length can be shortened, but the gain suffers. Also, thanks to the FCC, we have very strict limitations on the frequency bands available (the higher the frequency, the shorter the wave length, and thus smaller the antenna and consequently higher the gain). FCC makes many RF devices work at lower frequencies than we RF engineers would like them to operate at. Also, due to fear of signal from one device interferring with other devices, FCC puts limits on the amount of power a device can put out.
Given these considerations, the A210 and BT250 which are required to have excellent power efficiency (8 hours talk time and 240 hours stand by time) and also small and compact size (very small batteries and small antennas) provide a range which is not quite satisfactory. I walked at a radius of 10 feet and even with walls, metal partitions, etc, the signal strength was not that affected. How ever more than 10 feet, the signal had so much noise in it, I had to move closer to the adapter.
To be honest with you, I am not happy with the range. I dont think the range is $130 worth (for the adapter and headset = $50 + $80). Period. For a 10 feet range the cost should have been more like $50 (for both).
So basically, we have reviewed some basic factors. However, there is one major design flaw that I would like to bring to your attention. That is: The head set and the adapter enter in to stand by mode after one minute of non-usage. So even when you are in the middle of a call and both parties keep silent for more than a minute, the head set and the adapter stop communicating. The call is NOT disconnected. You can either pull the adapter jack out of the cell phone and put it back in, or press the volume key on the cell phone (basically do some thing with the cell phone) and you will be able to resume the conversation on the bluetooth devices. How ever this is not voice operable. Meaning, if the adapter and the headset enter in to stand by mode during the conversation when both parties to the call are silent, even when they both start talking, the adapter and the head set do not start communicating.
This is extremely uncomfortable. If I have a blue tooth head set and adapter kit for which I have paid $130 or more, then I want absolute mobility with out any reason to come back to the adpater unless I do so from my own free will.
Lastly, here is a recommendation for the people who designed this set. You need to incorporate greater features in to this adapter and head set. It should be able to not only handle voice data but also music and other types of audio information. This means you might need to use a more efficient method of modulation. Maybe you are using FSK which is constant envelope modulation (I deal with military and radar communication, so I dont know what modulation is used for blue tooth), but you cannot include too much information in to the FSK signal. Try using QAM, maybe not a very high order QAM, but some thing capable of handling all audio information. All you will need to change in the design is: a new power amplifier which is high efficiency and linear. Probably a class E or Class F with feed forward or Envelope elimination and restoration (Kahn) or Doherty principles. It is simple. You will need a one time engineering development cost, but in the long term - with market domination and mass production, it will more than make up for it.
As for buyers. If you are rich, a techno geek or a business person constantly on the phone - Go for this. It is good.
But if you have limited resources (money) then buy a simple wired hands free kit. In fact at times when the battery is down or I have to move to get back within range, I long for the reliability of a wired handsfree kit.
Update: June 25th, 2005: By the way, I lost one A210 and recently purchased one more. I tried one more test on it recently. I got a adapter from radio shack (Part # 274-397) which accepts 3/32" submini stereo plug ( as is the plug of the A210) and fits a 1/8" mini stereo jack (as is the plug for all standard head phone jacks). Thus I connected the A210 to the adapter and connected to my new Creative MuVo MP3 player. Then put on my BT250. It worked!! I could hear the music through the blue tooth set up!
BUT the music quality was poor... this blue tooth unit probably has enough sampling rate for speech, it is not able to handle the sudden and faster changes in amplitude, phase and frequency of a music signal.
Nevertheless it works.
Kaushik.
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Jabra A210 Bluetooth AdapterDon't have a Bluetooth-enabled phone, but want all the convenience and freedom that Bluetooth headsets afford? Check out the Jabra A210, a handy Bluetooth unit that offers the perfect way to retrofit your phone for compatibility with the latest Bluetooth headsets. The device works with any cellular phone fitted with an industry standard 2.5mm headset jack. The A210's internal, rechargeable battery provides up to 8 hours of talk time and 240 hours on standby, so you'll have plenty of time to roam freely and enjoy the benefits of Bluetooth. In fact, you can make and receive calls from as far away as 33 feet!
The A210 supports voice dialing and a three-position setting switch provides optimum connectivity for your phone type. Meanwhile a blue LED indicates power status while a red LED indicates charging and low battery level. At a weight of less than one ounce, dimensions of 1.5 x 2 x .3 inches, and an included velcro attachment that allows you to affix the unit to your phone, the Bluetooth 1.2-compliant A210 is the perfect way to get new versatility and functionality from your existing phone.
What's in the Box A210 Bluetooth adapter, AC power adapter, belt clip, velcro tape, user's manual.
Click here for more information about Jabra A210 Bluetooth Adapter
