Transact SQL :: Grouping Similar Rows After Unpivot?

I've unpivoted some data and stored it in a temp table variable

idNumFreqDtFreqrn
16100120120101M2
16100120120101M3
16100120100101M4
16100120100101M5
16100120060101M6
16100120000929Q7
16100119990101A8
16100119970101M9

Using the above data, if two rows have the same FreqDt, I want to see the record with the lowest row number.

So it should look like the below

idNumFreqDtFreqrn
16100120120101M2
16100120100101M4
16100120060101M6
16100120000929Q7
16100119990101A8
16100119970101M9

I've used the below code to accomplish it

SELECT DISTINCT
CASE WHEN t2.idNum IS NULL THEN t1.idNum ELSE t2.idNum END,
CASE WHEN t2.FreqDt IS NULL THEN T1.FreqDt else t2.FreqDt END,
CASE WHEN t2.freq is null then t1.freq else t2.freq end
FROM @tmptbl as t1 LEFT JOIN @tmptbl as t2
ON t1.idNum = T2.idNum
AND t1.FreqDt = t2.FreqDt
AND t1.rn = (t2.rn-1)

After all this, I'm supposed to condense the result set to only include sequential frequency dates with unique frequencies.should look like below (this is where I'm stuck)

idNumFreqDtFreq
16100120060101M
16100120000929Q
16100119990101A
16100119970101M

answer is below:

SELECT T1.*
FROM @t as t1 LEFT JOIN @t as t2
ON t1.idnum = T2.idnum
AND t1.freq = t2.freq
AND t1.rn = (t2.rn-1)
WHERE t2.idnum IS NULL