This is the largest device on the Oric motherboard and modulates the Final screen signal output from the UHF circuit with a UHF (Ultra High Frequency) carrier in order for it to be an acceptable signal for a normal TV. The UHF modulator may, in itself be considered a transmitter.
Other computers, like the Commodore 64 and Spectrum +3 generated sound through the TV. This is not supported on the Oric although replacing the existing UHF modulator with the type that supports a separate sound Input signal is quite feasible. The only problem is that the latter modulator is about 1.5 times larger (physically) than the existing.