[Kenwood] 'Tricking' the TS-440 filter selection

[Mike Besemer (WM4B)]

Greetings all,

Is it possible to 'trick' a TS-440 into going into narrowband by lying to it
about what filter is installed?  

I run a lot of PSK-31, and with NO filter installed on my rig, I've got too
many problems with QRM.  I'd like to put the narrowest filter possible into
the rig (the YK-88CN is 270 hz... which is really still pretty wide for
PSK-31... I'd like to go even narrower), but according to the chart in the
-440 manual, with a YK-88CN installed, the bandwidth is not affected in USB
mode (where you need to be for PSK-31).  Can I move the jumpers around to
make the radio select the narrow filter in USB mode as well as in CW?  What
about the INRAD filters (or any others)?  

Thanks in advance.

-- de WM4B
Mike
Kathleen, GA