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

At home just trried this D-Link antenna on my Linksys WRT54G Wireless Router
(replaced one of the two WRT54G's antennas with this D-Link ANT24-0600
antenna, with its included RP/SMA Connector), hoping to (as D-Link claimed
at its website http://www.dlink.ca/product.php?PID=182):

* Extend the Range of Your Wireless Device
* Improve Directional Coverage
* Provide 2 to 2.5 times the output over bundled dipole antennas (2dBi)
* Work with 802.11b & 802.11g Networking

But unfortunately I didn't see much improvement (if any at all) in wireless
signal strength and/or area of wireless coverage? Not sure if I didn't
install it properly or this this D-Link antenna simply does not do much at
all?

Regards,
James

 

DLink products suck and so does thier tech support.

 

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:
http://www.geeks.com/details.asp?invtid=SMCHMANT-6-N&cat=NET
which has the same specs as the Dlink.

 

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

 

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

 

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.

2. 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.

3. 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.

4. 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.

 

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: http://www.d-link.com/products/?pid=357), 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:

http://www.d-link.com/images/products/DWL-G710/DWL-G710_main.gif

Regards,
James

 

Bah. I knowledgeable electician can do it. It's not easy and there
will be some effort involved, but it's not impossible.
http://www.idealindustries.com/ht/DrillsAndBits.nsf
However, 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:
http://www.derose.net/steve/guides/wiring/
See 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:
http://www.multilet.com/us/baseband/index.htm
I'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.
http://www.cedmagazine.com/ced/2003/0603/id2.htm

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$70.

4. There are a variety of alternative firmware packages available for
the WRT54G which add many useful features.