[Elecraft] K2 Filter Question

[Curt]

I completed K2 s/n06424 about two years ago, the only option is the KSB2, 
rarely used.  The filters are OP1, 0.7, 0.4, and 0.1  The 0.7 and 0.4 
filters seem to exhibit what seems to me to be excessive signal attenuation. 
Strangely, this doesn't seem to be the case for the 0.1 filter.  This has 
always been true since the unit was completed.  Am wondering if somehow the 
passband is off.

Any advice would be appreciated.

73, Curt KB5JO