Hi, I finally exceeded the range of my hawking 6db usb antenna and the the surplus sat dish I used to increase range. Dish can't be mounted high enough to avoid the foilage at my new location. I am hoping to stay low cost still using both active and passive usb extenders I would like to find a usb "dongle" that has an rf connector option to adapt to a pole antenna - yagi or lightweight sector dish. I have almost 40 ' of usb and can waterproof the dongle - pigtail connection on pole. trying to avoid cost of power over ethernets / amplifiers and signal loss over cable run on what will be only a 6 week deployment. Any suggestions?
You can only go so far with USB. Most (not all) USB amplifiers require a +5VDC power source at the radio end. I've done 80ft with and amplified USB extension, but had to run seperate power leads for the USB amplifier. Recently, I've seen USB extenders that don't require power at both ends. The are mostly made of USB cameras and therefore will not tolerate much of a power load. I have no experience with these and have no clue if they actually function. IOGear GUCE50 |
Startech USBthere (various models) |
However, prices are $80 to $200, so methinks that may not be a practical cheap solutions.
Of course, you could modify a USB radio radio and attach your own coax connector or pigtail. Look for one with a tilt-up 1/4 wave antenna as they invariably have a small length of coax going between the board and the antenna. Chop the coax at the antenna, attach a proper connector, and mount it inside the case.
Most of the USB "thumb drive" size radios use PIFA antennas. These can be unsoldered and replaced with a coax cable connector. See: |
's the inside of a Dlink DWL-122 showing the antenna. I unsoldered the PIFA antenna, installed an SMA connector, and used it much in the same manner as you're suggesting. The problem with this idea is that the DWL-122 proved to be a rather mediocre radio with the added enjoyment of a flakey USB driver. However, at $15/ea, these were difficult to resist.
I usually end up with an "EtherAnt" type of antenna using some form of PoE.
built-in 18dBi antenna should be more than adequate. However, you probably won't like the $350 price.
Another alternative is to use an ethernet client radio and PoE. Since cheap seems to be the driving requirement, I suggest a WRT54G router ($70 list or $45 after rebates) with alternative firmware that has a client mode:
nice thing about this particular radio is that the has a very wide range of useable power supply voltage. Therefore, you do not need the fancy PoE devices, with it's low copper loss 48VDC power supply. I don't like butchering the CAT5 cable, so I just run a seperate pair of wires for power. You can use the supplied 12VDC wall wart, tolerate whatever copper losses are involved, and still end up with enough power at the radio. The range of input voltages is approximately 4VDC to about 18VDC. This is my BEFW11S4, which has a similar power supply arrangement, running on 3.5VDC:
rest, I think you may have some experience with. Find a decent antenna for your pole, and deal with the water proofing, packaging, mounting, alignment, etc.
Also, you mentioned yagi and sector dish. I don't like yagi's for
2.4GHz. They have the highest cost per dBi of gain. They are fairly difficult to build, have lobes in weird places, and become very long at gains over 14dBi. Also, there's no such thing as a "sector dish". Most dish antennas have a beamwidth (depending upon gain) of 5 to 20 degrees, which is hardly a sector. For do it thyself, I prefer: Patch or Biquad 8-10dBi gain Panel antenna 10-18dBi gain Dish 18dBi to 24dBi
Search eBay for "usb orinoco" and you will get what you need but not exactly what you ask for in the subject. See item 5782381006 where they opened one up - you get a USB interface and a PC Card client but the pigtail is not SMA (or more accurately the RP-SMA often used in Wi-Fi) but nevertheless it is readily available.
Thanks Jeff, My usb2 active extension is only $25 but it is also only 16'
. I put 2 10' passive extenders downstream and it still runs the hawking hwu54d. I'll have to look up its power requirements to see how it compares to a $57 buffallo client I found on the net that appears to come with rf connector for external antenna. I should be able to get away with another passive in front of the active extender if i need more length but my main reason for looking at the yagi or what I mistermed a sector dish (meant grid antenna) was light weigh and low wind resistance. I haven't selected a mast but again looking for low cost simple installation - maybe pvc - the yagi looked lowest in weight of the directional type - but the grid type or cantenna might also fit this requirement. Frank
The official maximum USB cable length for USB is 16ft. Two things will fail if you go farther. The data waveforms get "smeared" and the
+5VDC power drops below where the device fails to function. I've tried longer lengths of cables and had random success. Some things worked, some didn't. If you can get away with it, by all means, use it. However, don't count on it working with every USB device.
Some of the devices were original made for a connector. For example, this ancient Linksys WUSB11 radio has pads and holes for an SMB connector.
the pads in the upper right.
I like to call it a "barbeque grill dish". If wind resistance is a problem, then large panel antennas will be a problem.
PVC will sag and move around in the wind. Think Radio Shack steel pipe and tripod base. They're cheap, strong, and easy to install.
Well, if weight is an issue, try carbon fiber tubing. Costs a small fortune but is really strong and light. |
1.120 OD and 72" long, only $318.
I have a bad attitude about can antennas. They work and are usually good enough. However, I prefer a biquad antenna, which methinks is better, has more gain, more bandwidth, etc. If you can live with
8-10dBi of gain, then a coffee can or biquad will work. If you need more, methinks a dish will be best.
Coffee Can: |
I did this chart a few months ago from the
web site prices. They're probably somewhat cheaper these days, but I'm too lazy to do it again. Note that the yagi is the most expensive in cost per dB of gain.
Type specified -3dB bw Cost Cost per gain dBi degrees $US dB gain