copied from UUCP:
>From: stan@hprpcd.HP.COM (Stan Witherspoon)
Newsgroups: rec.ham-radio
Subject: Re: Yaesu FT-411 mods?

To allow the FT-411 to recieve from 130 MHz to 174MHz and to transmit
from 140 MHz to 151 MHz, turn off the radio and hold down both of the arrow 
keys  and turn on the radio. Be sure to write down all of the contents of
your memories first as this will erase them ! This is the MARS modification. 
Repeating this procedure will turn the FT-411 back into a HAM only transciever.
Refer to the mods server for a more involved mod that will allow you to 
set the transmit and recieve frequency limits at will within the capability
of the rf deck. 

WARNING: Do not transmit over the air outside of the ham bands unless you have 
the appropriate MARS license! For other frequencies, don't transmit at all
because the FT-411 is not a FCC-Type-Accepted radio for the public service
bands! Also make sure that your radio can't accidently transmit  on a public
service repeater ( in case you are all thumbs, or your radio gets stolen!)

  Stan Witherspoon 
  RF: N6SCE        

Note: I haven't tried this, proceed at your own risk.  WA2ISE