"I know the 401 cards are talk only, no dial capability."
Let me be mistaken the 401 cards are a family of cards..I don't get the question?
The Intercom card is simular to any 401. Although, one would need to wire talk batery in to the KTU 400 TR intercom card off a DC source from the power supply. Again we talk on DC supper imposed. Once you begin to talk the wave is now AC.
Hope this helps you?
