Convert UTF-8 string to ANSI

CREATEFUNCTION dbo.fnConvertUtf8Ansi
(
    @Source VARCHAR(MAX)
)
RETURNSVARCHAR(MAX)
AS
BEGIN
    DECLARE @Value SMALLINT = 160,
            @Utf8 CHAR(2),
            @Ansi CHAR(1)

    IF @Source NOTLIKE '%[ÂÃ]%'
        RETURN  @Source

    WHILE @Value <= 255
        BEGIN
            SELECT  @Utf8 =CASE
                                WHEN @Value BETWEEN 160 AND 191 THEN CHAR(194)+CHAR(@Value)
                                WHEN @Value BETWEEN 192 AND 255 THEN CHAR(195)+CHAR(@Value - 64)
                                ELSENULL
                            END,
                    @Ansi =CHAR(@Value)

            WHILECHARINDEX(@Source, @Utf8)> 0
                SET    @Source =REPLACE(@Source, @Utf8, @Ansi)

            SET    @Value += 1
        END

    RETURN  @Source
END