[Elecraft] RTTY filter shift

[Peter]

Hi

Just did some playing with rtty and the K2.
I have a strange  thing with the filter setup

I have set my filter for rtty in 1,5, 1, 0.5 and 0.25 kc. Using 1275/1440 tones.
I get the filter setting ok for all beside the 1 kc. When I use this filter I notices a
jump of the center freq for about 40 hz lower.
When set to rtty reverse this is not happening.

Any idea how to tweak this?

Peter