My advice to you is to learn more than just being a "TCO". When you work as a TCO understand what exactly the phone installers are doing. Take a trip down to the switchboard and see what the civilians are doing and how they configure the DSN switch to allow and disallow certain user privileges. Ask them what certifications and/or degrees they have and follow that career path. It will all carry weight on a resume. But like chief said, you should get a lot of experience being a 25U dealing with Tactical Comms.