Usually if you send a copy, via email is fine, of your mars license or even 
the email or letter saying you're application was accepted and you can go on 
with trial status, send that to the manufacturers via email is fine and 
they'll usually email you the correct mod pretty fast. That way you don't 
run in to that one wrong mod online that will give you problems. Not that 
usually there is one, but I've heard horror stories in the past. Also for 
future reference, I'm told when you order a new radio, more often than not a 
lot of the places, upon seeing your mars license again via email or what 
ever, will do it for you before shipping. Most 2-way radio shops will do it 
as well if you bring the radio and paperwork but the rates aren't worth it. 
Or, there's always someone willing to help you with in the MARS group too.
----- Original Message ----- 
From: "Steve Forst" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Wednesday, February 13, 2013 3:38 PM
Subject: Re: MARS question


> Albert,
>
> The MARS mod on the 590 is to open up a surface mount resistor.  I think
> it is R900, but you need to confirm that from a reliable source.
>
> While it is considered  a "resistor" it actually has zero ohms
> resistance and acts as a jumper.    Some guys cut it with an x-acto
> knife, or crush it with needle nose pliers.   Others will unsolder one
> end and lift it off the pad so it could be reinstalled later if you
> wanted to restore the radio to  ham band only transmit.
>  In any event, you will need sighted help on this one.
>
> 73, Steve KW3A