Question on D-Link ANT24-0600 2.4GHz 6dBi Indoor Directional Antenna

The antenna is apparently a patch antenna, which has a gain of about

6dBi. However, Dlink (and most others) do not seem to find it necessary to include the coax cable and connector losses in their specifications. The data sheet shows 1.5meters of ULA-316 coax cable which has a loss of 2.5dB/meter. The connector and adapter are good for another 0.5dB loss. So, the real antenna gain is: +6dBi - 3.7dB - 0.5dB = 1.8dB or about the same as the stock antenna. I wouldn't expect to see any improvement (except by improvment in location or line of sight).

Specifying the gain of an add on antenna without including the cable and connector losses is deceptive advertising and apparently epidemic among antenna vendors that include pigtails. Will it really require a hint by the FTC to get their attention?

Jeff,

Thanks for your reply, and I think your input/info on the unit's coax cable and connector losses does make sense.

Maybe I shall forget about it!

James

Whether it works for you depends upon what problem you're trying to solve. An omni antenna will spray RF in all manner of undesireable directions, createing reflections and receiveing interference. A directional antenna, with the same amount of gain will reduce these reflections and interference. Lots of other possibilities. One is if you're using a PCI 802.11 card with the antenna mounted on the back of the computah. Not a great location as it's usually low towards the floor, behind the computer case, which acts as a shield, and mixed in with a mess of cables. By moving the antenna away from the nighmare that was behind the computer. an external and properly located antenna is a good thing.

Incidentally, I was wondering about the 6dBi gain. A full size air dielectric patch antenna has a gain of about 8 dBi. I'm guessing that the DLink antenna is a ceramic backed patch and is therefore smaller, with a lower gain. Unfortunately the data sheet for the Dlink does not specify the patch diameter making guesswork difficult.

Also, apparently not all such antenna manufacturers are clueless. SMC mentions the coax cable attenuation in:

has the same specs as the Dlink.

A WAP54G setup as a repeater on the main floor should help Or you can move the WRT54g to the main floor and that will center the signal distribution, but if you can not move the WRT54g then the WAP54g in repeater mode will do the same job wirelessly. TeddyBare

Jeff,

Again thanks for your reply.

I returned that D-Link ANT024-0600 antenna.

In my case, I have a Linksys WRT54G 802.11g wireless router in the family room on the 2nd floor beside a destop machine and the cable modem at home. I have a laptop mostly used on the main (1st) floor living room, and another desktop machine in the basement. The laptop has built-in 802.11.g wireless, and the desktop machine in the basement has a Linksys external USB-interface wirless network adapter. My problem is that the laptop in or around the living room or in the backyard or the desktop machine in the basement does not have enough wireless signal strength. So I am looking for a relatively powerful wireless antenna extender...

Thanks, James

Jeff,

Thanks again for the detailed info.

One problem with running whatever cables from the 2nd floor (where the cable modem sits) to the main floor or to the basement is, it requires drilling holes and running cables behind the wall, above the ceiling or below the floor, which is a bit hard...

At a local Stamples/Business Depot store here I just saw this wireless repeater from D-Link (High-Speed 2.4 GHz 802.11g Wireless Range Extender WDL-G710:

, perhaps I shall give it a try (placing it somewhere on the main floor). But this WDL-G710 is not cheap at the moment, for $99 Canadian (about $82U.S.)! The unit looks like this:

Regards, James

USB-interface

There are plenty of solutions available:

1. Run CAT5 wire to the desktop in the basement. If CAT5 is not available, borrow 4 telco wires, or use a 10baseT to 10base2 converter over coax cable. Details on request.

1. Run CAT5 to a 2nd access point on the 1st floor. Setup the access point on the same SSID but a different channel (1, 6, or 11). You can use a wireless router as an access point if you: - Disable the DHCP server in the router - Setup the IP address for something in the same class C network as the router, but on a different IP address. - Ignore the WAN port. - Run the CAT5 between LAN ports on the 2nd floor WRT54G and the 1st floor router.

2. Use another WRT54G as a WDS repeater on the 1st floor. Run CAT5 from this router to the 1st floor desktop. The catch is that the wireless bandwidth will be cut in half, but that should not be a problem if your cable modem speed is much less than the wireless speed.

1. Some exotic kludges that I don't wanna mention (i.e. using the heating duct as a waveguide between floors).

Coverage to the backyard may be a problem. Try to place one or more access points in windows that face the yard.

Bah. I knowledgeable electician can do it. It's not easy and there will be some effort involved, but it's not impossible.

besides the obvious danger involved in drilling through existing electrical wiring, be sure to seal the hole between floors to prevent the air draft from propogating a fire from below. (That's why they call the short horizontal studs "fire breaks"). General advice: the section on flexible drill bits.

Any chance that you also have CATV cable on the 1st floor and basement? If so, you can "piggy back" data on top of CATV. See:

've done the same thing using do it myself baluns, with tolerable results. 10mbits/sec maximum.

If you're into do it thyself, it is also possible to use the exiting coax cable to shovel 2.4GHz between floors. The losses with RG-6/u will be horrible, but probably less than free space loss plus wall attenuation. You'll need to build a splitter (hi-pass/lo-pass at about 1.5Ghz) to seperate the signals. This isn't easy, but it can be done.

Bad idea for several reasons.

1. DLink and Linksys generally do not mix. The problem is that for a repeater to work correctly, the chipset generally needs to be the same between the router and the repeater. Linksys WRT54G uses Broadcom. I'm not sure what DLink uses in the DWL-G710. I could look it up on the FCCID web pile, but I'm lazy tonight. Check the data sheet on the repeater to see what devices are supported before buying.
2. You already have half the puzzle for doing a repeater. WDS (wireless distribution service) is a repeater. All you need is another WRT54G running WDS and you have exactly the same thing as the "range extender" contraption.
3. WRT54G routers sell for US.
4. There are a variety of alternative firmware packages available for the WRT54G which add many useful features.