>From a sheet that I got from a vendor, here 'tis:

MARS/CAP (Wide band transmit)

1. Remove battery and antenna.
2. Remove front case assembly block by unscrewing.
3. Remove tthe copper plate around the back side of the display section.
4. Remove the diode indicated by D2, and add a diode 1SS301 leaving other
   components intact as per the following drawing.
5. Reassemble radio and install battery.
6. Turn on power and execute master reset.

---------------------------------------------------------------------
------------+             +------------------------------------------
            !             !
            !           +------+         (PC board "donut")
            !           !      !                /
            +-----------+      +------+        / 
                        !      !      !   /---\
   PC board trace/      !   D1 !      +--+ +++ !      +-----+
   component layout     !      !      +--+ +++ !      !     !
            +-----------+      !      !   \+-+/ +-----+-+   !
            !           !      +------+    ! !  !       !   !
            !           +-+----+         +-+ +--+       +---+
            !             !              !      !       !     <<< ---- CHANGE
            +-------------+              !      !  D2   !
                                         +------+       +---+
                                                !       !   !
                                                +-----+-+   !
    "Not to scale"                                    !     !
                                                      +-----+ 
                                             **
                                             **
                                            \**/
                                             \/
               +--------+                 (about here)    +------------+
               !        !                                 !            !
               +--+     !                  +----+         !            !
  PC board locator!     +-----------------/------\--------+            !
               +--+                                                    !
               !                                                       !
               !                                                       !
               !                                                       !
               ++                                                +-----+
                !                                                ! 
               ++                                              +-+
               !                                               !
               !                                               !
               !                                               !
               !                                               !
               !                        Opening for            !
               !                        speaker about          !
               !                        here (funny            !
               !                        shaped opening)        !
                ...............................................

I received the diode yesterday, and installed it.  The mod DOES work!!!!
I have not tested the ranges, but it DOES cover the entire 420-450 band
now, which is what I was most interested in.  
 
73/Kurt
-- 
Kurt Freiberger, wb5bbw   kurt@cs.tamu.edu