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Unleashing Remember our article on the (then new) “Unwired” wireless broadband system back in November last year? We liked it so much we signed up for a system. Ever since, we’ve wondered if it could be improved . . . E lsewhere in this issue, we report on a brief visit to the CeBIT show in Sydney. Like many of the exhibitors at that show, Hills Antenna & TV displayed a range of wireless equipment antennas and equipment. “Ho hum, not more . . . hang on, what’s this?” The item that caught my eye was a small (150mm square?) panel antenna, labelled “Show Special: 3.5GHz, 7dB External Antenna for Unwired modems. . .” Huh? How can you hook up an external antenna to an Unwired modem? When we looked at the Unwired broadband system we were reasonably impressed with its performance, if not its coverage. (I have to tell you that not much has changed in coverage, especially in our area). I have installed a permanent Unwired system and even though I pay for the top (1024) service, I have never found it to even approach that speed. Most of the time, it’s way under that. Apparently, the reason for the slow speed is that I am right on the edge of the Unwired service area. All I ever Here’s the Hills BC7243 13dBi flat panel antenna, similar to the smaller one that caught my eye at CeBIT. This one would be all most Unwired users would need. 14  Silicon Chip get is the “red” indicator LED – they say that means good, even though it’s the minimum usable signal level. An orange LED means very good, a green LED excellent. Not that I have ever seen those colours. (The LEDs would probably be better labelled marginal, reasonable and good). The antenna on the Unwired modem is semi-fixed. Called a “rabbit ear” for obvious reasons, it can rotate through 180° but that’s all. Unlike their opposition (iBurst) wireless modem, there is no provision for an external antenna on the Unwired modem. (While it’s true iBurst include an external antenna socket, so far noone has come up with the appropriate plug to actually connect to it!) I had toyed with Stan Swan’s idea of a WiFri antenna, mounting the Unwired modem so its antenna was at the focal point. Somehow, I never quite got around to doing it . . . At CeBIT, I got to chatting to Rolf Roelfsema, Hills Antenna’s Microwave Product Development Manager. I asked him about that external Unwired antenna and also about the apparent inability to plug it in! Almost conspiratorially, he replied “If you – ahem – remove the rabbit ear you’ll find it plugs into a standard MCX connector. So if you want extra range or a boost in performance, you can easily do it.” “How can you remove the rabbit ear? There’s not a screw nor a clip anywhere on the modem that I could find.” “It’s really easy once you know how,” he said – and then explained how to do it! “What do Unwired think of this,” I asked. “Unwired don’t condone it,” he said. “In fact they say you void the warranty if you remove the rabbit ear. . .” Incidentally, I understand that since CeBIT, Hills plan to start talking to Unwired to “legitimise” what is obviously a win-win situation for both companies . We then started chatting about other antennas they had which would do an even better job than the tiny panel antenna they were offering. “This panel (the one on display) gives a bit better performance than the rabbit ear but Hills has a range of 3.5GHz antennas which will give you siliconchip.com.au Unwired by Ross Tester The trade secret: how to remove the Unwired “rabbit ear” antenna to reveal the antenna socket underneath! Here’s the Unwired modem with the rabbit ear closed. See those two little raised marks on the seam . . . line them up by rotating the ear, just like this, and you should find that the antenna can be pulled out and off. . . revealing the standard MCX antenna socket inside. It’s a push-in type, not a screw-in type. far better results,” he said. “Once the madness of CeBIT is over, why don’t you come out to Hills and we’ll go through what is available.” So it transpired that a week or so later I made the cross country jaunt to Riverwood (a good hour’s drive away from the SILICON CHIP offices) and met up again with Rolf. There he showed me a range of antennas, some of which had started life as 2.4GHz WiFi models but had been adapted for the higher frequency (3.5GHz) Unwired. Two in particular stood out. One was not too dissimilar to the antenna I’d seen at CeBIT: a low-profile flat panel antenna, 190 x 190 x 20mm, suitable for outside or inside use, pole or wall mounted (or, as Rolf pointed out, can sit flat on a desk or filing cabinet, etc). With a gain of 13dBi, this antenna has a horizontal and vertical beamwidth of 35° so is not just high gain, it’s also rather forgiving of aiming errors – close enough is probably good enough. It has a UV-resistant ABS radome and aluminium backplate, mounted on a diecast aluminium bracket and is suitable for horizontal or vertical polarisation (though as an Unwired antenna would be vertical). An integrated type-N female socket connects to the outside world. The second antenna was a more traditional parabolic grid “dish”. This one, according to Hills, will normally lift your Unwired signal level up two LEDs and often gives you wall-to-wall signal even in otherwise dodgy areas. Hey, sounds like my Unwired service! The rugged, powder-coated grid antenna is actually available in three sizes, with 16, 19 and 25dBi reflector options. Naturally, the higher the gain, the less forgiving the antenna will be about aiming – the 25dBi model only offering 10° horizontal and 8.2° vertical beamwidth. Still, for someone with signal levels down in the mud, a few more minutes up a ladder getting the aim just right is hardly going to matter in the long term. And this is one of Hills’ big guns, a 16dBi powder-coated parabolic grid antenna (Part No KC4253) which plugs into the Unwired modem via a downlead (black) and patch lead (white in this case). Other (larger) models have even higher gain. This antenna is a little bent out of shape (it’s been doing the rounds of the shows). But it still works perfectly – in fact, I couldn’t stop it working no matter where I aimed it! siliconchip.com.au Connecting the antennas Connecting any antenna in the GHz range is always something of a challenge – and both these antennas proved to be just that. It’s a compromise between location (and that means distance) and loss. But, as they say in the classics, where there’s a will, there’s relations. Woops, sorry, wrong proverb. The panel antenna outputs to an integral “N” female connector. The grid antenna outputs via a 600mm coax downlead, terminated in an “N” male or female connector. The Unwired connector mates to an MCX plug and this, at the moment, can only be fitted to RG58 coax. Now as any amateur radio operator will tell you, RG58 is at best marginal at upper HF, very lossy at VHF frequencies. . . and at 3.5GHz it’s hopeless. So only a very short length of coax can be used (we tested it with 2.5m). That’s fine for one popular method of mounting: the antenna and Unwired modem in the roof cavity (ie, under shelter), with the modem connected July 2005  15 These two adaptors from Hills allow direct connection between the panel antenna and the Unwired modem. via a longer Ethernet cable. But it’s not too realistic if you want to mount the antenna outside and the modem inside. Hills are working on that little dilemma and expect to have a solution available even before this issue hits the streets. A possible alternative for the panel antenna is direct (ie, no coax) connection using a couple of adaptors which Hills have as standard stock lines. Just like WiFi access points which we talk about elsewhere in this issue, it’s no big deal to mount the Unwired modem in the ceiling and run a Cat5e patch cable back to your computer. You could even run PoE (Power over Ethernet) to the Unwired modem if you were really keen. You could do the same thing with the grid antenna by connecting the appropriate adaptors to the (fitted) coax cable. Of course, both of these options are null and void if you have aluminium-backed insulation in your roof/ceiling or you have a very old or very new house with corrugated iron roofing (isn’t it funny how we used to despise corrugated iron!). Doin’ it! First we will look at the panel antenna. As our close-up photos show, two adaptors are used to go from the male “N” connector to the Unwired modem. These are a MCXto RPSMA (Hills part no BC7240) and a RPMSSA to “N” (male) (Hills part no BC7263). Note that the Unwired socket is a pushin, not a screw-in type. Taking the mounting brackets off the panel antenna allows the Unwired modem to fit right in behind it. The modem could be packed up by a couple of millimetres if you wish; we didn’t bother as it seemed to be close enough. Now all you have to do is aim the antenna while watching the red/orange/green LEDs – unfortunately that’s no mean feat because the panel is in the way. But you can see them – just! When you get the best operation, set the antenna and modem in that position and you’re ready to see how much better/faster/both your Unwired signal is. The grid antenna is both a little easier and a little more tricky. Because it comes with both a downlead and a modem extension cable, siting it isn’t quite as difficult. But as we said before, it’s a lot less forgiving when it comes to aiming it. Still, 16dBi gain means you should have a lot more signal to play with – the optimum point of aim will just be that much tighter. External mounting If you need to mount the system outside, you may be able to get away with the 480mm downlead and the 2.5m patch lead we tried – especially if you mount the Unwired modem close to the point where the lead comes in from outside and run Cat5e back to the computer (similar to the panel antenna above). Otherwise, you’re going to need to With those two adaptors shown above, the Unwired modem can connect directly to the BC7244 panel antenna as shown here. They are not exactly in the same vertical plane – perhaps a milli-metre or two out – but they are close enough for us! This would obviously be an “inside” installation but if some form of suitable weatherproofing was available (only needed for the Unwired modem, not the panel), we might even be tempted to try this setup outside! 16  Silicon Chip get some very low loss antenna patch leads. They are available but they’re not cheap. Don’t go for any longer than you absolutely need because every extra metre means more lost signal. Remember too that while Nconnectors are designed to be low loss themselves, every extra connector in the system introduces more loss. Of course, you could ferret out some low-loss coax and connectors to make up your own patch leads – but that’s probably not worth your while. OK, how did they go? It is still early days yet but both antennas gave a significant boost to my Unwired signal. For the first time, I’m seeing signal strength LED colours other than red – the panel antenna gave me an orange and the grid antenna, aimed correctly and above the insulation inside the roof, always gave a solid green. (In fact, aimed anywhere – 180° from the nearest Unwired tower, even straight up in the air or straight down, it always gave at least as good performance as the rabbit ear!) And speed also seems to be increased. I haven’t really had the chance to review it for a long period nor in all weathers – the forecast is for a wet weekend (rain used to knock my Unwired around a bit!) so that will be interesting. I’m happy: the antenna investment is well worth it. Unwired isn’t the cheapest service so you really need to extract every bit of performance that you can. For the sake of well under $100 (panel antenna, including adaptors) or a bit over $100 (grid antenna and patch lead), your sluggish Unwired service can really start to sing. One other benefit which some readers might find attractive: following our Unwired feature, Av-Comm’s Gary Cratt wrote a coupe of articles about Unwired and similar wireless broadband knocking the stuffing out of satellite TV reception. With a highly directional antenna such as the parabolic grid, you just might be able to have the two services co-exist. No promises – but it could be worth a try! SC Contact: Hills Antenna & TV Systems 12 Wiggs Rd, Riverwood, NSW 2210. Ph (02) 9717 5290 Fax: (02) 9717 5298 (Or local offices in all state capitals) Web: www.hills.com.au siliconchip.com.au