On Sun, 3 Apr 2005 03:03, Brian Reichert wrote: > Some cards have an antenna built right onto the card, and others > seem to come with a remote antenna that hangs off of a six-foot (or > so) cable. > > The vendors' arguments for the cable arrangment is that it allows > for a more optimal placement of the antenna, but other lore suggests > that the cable itself introduces loss of signal. > > Does anyone have a concrete opinion on this, or can point me in the > right direction for some research?
An onboard antenna will suck - if it's a Cardbus card it will be some dinky PCB dipole with minimal gain (which you can't reorient for your environment). If it's a PCI/mini-PCI card then it will be inside your PC and suck even more so they need an external antenna. (And I've never seen a [mini-]PCI wireless card without an antenna connector). Lots of cards have a diversity arrangement where they have 2 RF paths, 1 is on the PCB and the other goes to an external antenna port. If you plug in an external antenna it will almost certainly get more gain and be used in preference. While cable loss can be an important factor it is usually not an issue if you choose appropriate cabling and antennas. It may be a problem if you need to do a long run (>20m) but that is pretty rare, and in that case you might want to consider relocating the box to be closer to the antenna (or using a USB wireless interface :) I would guess most vendors reasoning for not putting an external antenna connector on a card is cost. Most people don't use them on Cardbus interfaces and they cost a reasonable amount. On my (terribly ancient) DWL-650 card it has PCB pads for a connector but it isn't used (the shell prevents it) but it was fairly easy to modify the card to have an external connector. (YMMV, fire/smoke warning etc) -- Daniel O'Connor software and network engineer for Genesis Software - http://www.gsoft.com.au "The nice thing about standards is that there are so many of them to choose from." -- Andrew Tanenbaum GPG Fingerprint - 5596 B766 97C0 0E94 4347 295E E593 DC20 7B3F CE8C
pgpb8XYOOLcPT.pgp
Description: PGP signature