The rate of mortgage application activity provided mixed results in two weekly surveys. The Mortgage Bankers Association (MBA) weekly survey of gross mortgage applications was down 2.1% on a seasonally adjusted basis for the week ending February 12, compared to one week ago. However, the Mortgage Maxx index (MAX) that’s adjusted to reflect the number of households applying for mortgages was up 0.4% for the same period. “[G]iven the weak start to the New Year, the MAX may be telegraphing that the extension of the first time tax credit is also providing diminishing returns.  If spring transactions turn into a bust, look out for a double dip below,” Mortgage Maxx said in its weekly report. The MBA said its seasonally adjusted refinance index was down 1.2% and its seasonally adjusted purchase index decreased 4%. Refinance applications took a 69.3% share of total applications, down from 69.7% a week ago. Adjustable-rate mortgages (ARMs) took a 4.4% share of application volume, down from 4.5% a week ago. Write to Austin Kilgore.