Thread: wrt54 antennas
View Single Post
  #6 (permalink)  
Old 07-26-2008, 07:13 PM
Jeff Liebermann
Guest
 
Posts: n/a
Default Re: wrt54 antennas

On Sat, 26 Jul 2008 11:02:17 -0700 (PDT), jimmie68@gmail.com wrote:

>Interesing, this has got me wondering how hard it would be to alter
>the software to use the the switch as a T/R switch.


Fairly easy. If you lift the metal shield from the RF section, and
follow the RF path inside, the first part it hits is a 2.4GHz ceramic
bandpass filter. The next part is the T/R PIN diode switch, which
should be the same chip as the diversity switch. A bit of creative
wiring should be able to make it do what you want. No sofware
required.

>My thought is to
>use one antenna for Rx with an antenna mounted LNA. I think I need to
>check in with the guys over at DD-WRT.


The diversity algorithm is part of the firmware for the Broadcom
chipset. I think (not sure) that the interface is supplied as a
pre-compiled linkable library and cannot easily be tweaked. That's
also why you don't much in the way of MAC layer (RF) statistics from
Broadcom. There was some effort made towards reverse engineering the
interface library, but I have no clue what's happening.

--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

Reply With Quote