Problem with HP mini 1104 wifi card in Ubuntu 12.04

I have a HP mini 1104 with windows 7 installed by default. When I install Ubuntu 12.04 and try to activate the proprietary drivers, I only see the graphics card.

When you connect to the wifi wireless card is turned off and intermittently, if it detects networks but does not have a stable connection.

My network card is a Ralink RT3593

Does anyone know the solution to my problem?

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