WRT54g Wireless Repeater
The Linksys WRT54G (and the variants the GS, GL and L54GS) was one of the more popular wireless access points. Unlike a lot of the newer routers and access points it does not come with a repeat mode by default but it is possible to re-purpose your old router to become a wireless repeater.
Making the WRT54G a Wireless Repeater
You won’t find an option for this in the setup but, if you feel up to the task, you can flash the WRT54G with a custom third party firmware which then gives you the option. Really this comes down to how comfortable you are working with computers. The guide is easy enough to follow step by step but I wouldn’t give it to my mother to do.
Once you flash it with the firmware you can configure it to repeat an existing signal rather than creating a new network as a router like it would normally do. It is a far cry from a simple setup of a standard wireless repeater and you also risk ‘bricking’ your router which basically means if something goes wrong while you’re changing the firmware the router becomes as useful as a brick.
Is it Useful?
If everything goes well and it is able to repeat a signal it can certainly be useful. You can swap in some high DBI antennas and it certainly will get you a better signal than using nothing at all. The flip side reports say it runs fairly hot so you do need to consider giving it enough time to cool off frequently. It seems to get a pretty solid signal but doesn’t really compete with some of the higher end repeaters out there for stability and signal strength.
In short I’d say it’s probably better than nothing and if you have it sitting around then sure, give it a try. But I don’t think it’ll be winning any awards as a repeater anytime soon. Personally I’d suggest going with a properly made wireless repeater which was made for the job, is easy to setup and gets a good strong signal and keeps it going.