[Icom] Pro2 question RTTY filter

[WA9ALS - John]

> Does the filter actually move?  If I do the same thing on a 
> PRO (not a II), as soon as I change the MARK frequency, the 
> RTTY Filter indicator goes off, and if I turn that filter on, 
> MARK goes back to 2125.
> 
> If the PROII behaves differently, that's a win.

It doesn't - behaves the same.  But why not set the LOW tones in the
menu if you want, leave the RTTY filter off, and adjust/choose filters
with PBT and filter button?  You just can't use Twin Peak Filters if the
RTTY filter is OFF.  I want to understand the considerations - I've
never used LOW TONES.  73