Given that the value of y = loga (3a-1) is always positive, then the value range of a is______ .
∵ loga (3a-1) is a positive number, or 0 ∪ a ∪ 13a − 1 ∪ 1, or 0 ∪ a ∪ 10 ∪ 3a − 1 ∪ 1, or & nbsp; 13 ∪ a ∪ 23
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