Remote control encoder

What is the voltage logic level (eg >2.5 V for logic 1 and <1.5 for 0)for the remote control encoder PT2262? The datasheet didn't state it.
I'm using a 315Mhz RC module. The signal is fed to an antenna, and I need to know whether resistive networks in the encoder circuitry affect the transmission strength?

Check the schematic. Does it say 0V low and 12V high?
[edit] I think it depends more on your transmit module than on the encoder chip. [/edit]