TM-281 Mod


Hello.  Here are a few pictures of my TM-281 APRS mod.  All went smoothly and it works great.  I soldered a shielded USB cable that was small enough to fit through one of the two cutouts on top of the rear radio heat sink. 

At the end is a male USB, which plugs into my TNC that I built following these instructions: 

Using the PL tone of 100 for APRS voice, the radio is silent and does not emit received APRS data audio from the speakers.  The received APRS signal goes to the TNC, while I can monitor APRS for voice alerts and not have to listen to the APRS signals coming throug the speaker. 

Using the TNC, I can use APRS with my phone and APRSDroid or on my computer with APRSIS/32.  It works great.

Thank you to Lloyd for posting instructions ( ).
Thank you to Joe KQ4BX for additional info provided for this mod.

More photos here:


Excellent looking mod Arion, Thank you for sharing.
I really like you found a way without drilling the case making it easier to complete.
Lloyd Gregory