Actiontec GT701WG & new antenna help?

[middlefinger]

Hi all.

I've had this router since NTL advertised it on their website, the router has been decent with no problems at all over a good few yrs.

Recently we've had an extension built on the side on the house and im struggling getting a signal on the lower floor in the extension from the router which is based in the attic.

I was thinking of buying a new antenna for the router but wasn't sure if this model of router would allow this. Im at work at the moment and I cant check so here's my question.

Do any of you guys know if this can be done with the GT701WG?

I was hoping a new antenna would help send the signal further and stronger than the standard antenna that came on the router.

Was also going to try the cantenna trick but i'd prefer a good strong antenna if possible.

Thanks for any help