[Yaesu] FT-900 CW Problem

[Darryl J. Kelly]

I have an FT-900CAT with personally installed 250 Hz CW filter, Yaesu stock.
On the low bands when I switch in the narrow CW filter, the noise jumps up
measureably.
It's just much quieter copy with the stock Collins SSB 2.8 KHz filter. Of
course I then hear everything nearby. I also am using a Timewave DSP-59Y
digital filter in an SP-6 speaker box. I have tried all kinds of
combinations IPO on/off, Noise blanker on/off, noise blanker on DSP59Y
on/off, bypassing DSP59Y, in/out AGC on both 900 and DS59Y. Any hints as to
what is going on, and any corrections, like an INRAD filter, preferably
another 250 Hz filter? TIA.
73,
Darryl, KK5IB