[Elecraft] K2 KSB2 low output

[gt-i at gmx.net]

Hello list,
I recently tried to use my K2 on SSB. To my suprise, there was very 
little output. Even with full power it only showed the first bar. I did 
some SSB QSOs during the first years...
Digging deeper, I found the DSB signal showed a Vpp of ~1V, but after 
the filter the SSB signal was only 20mV or so. Is this kind of loss 
normal for a 7-pole filter? If not, any hints how to repair the filter?
tnx es 73
Gernot DF5RF