main - mech
- main
- main access
- main amplifier
- main beam
- main board
- main busway
- main cable
- main call-signaling assembly
- main carrier
- main communication center
- main conference communication
- main control board
- main control unit
- main distributing frame
- main engineering communication
- main exchange
- main exciter
- main fax unit
- main feed
- main feed center
- main feedback
- main feeding center
- main lead
- main left speaker
- main level
- main line
- main lobe
- main memory unit
- main network
- main network node
- main processor card
- main profile
- main radio communication
- main radio relay line
- main right speaker
- main route
- main scanning
- main service
- main ship antenna
- main short-circuit delta
