This communications system is used when the telepathic circuits are unsuitable or unavailable.
It gathers non-telepathic signals through the Receiver Grid. The sensitivity is such that the Emergency Transceiver can receive TV broadcasts from anywhere in 20th Century Earth.
The Transceiver can be used to "hack" into
wireless computer networks,
satellite communications, and cell phone networks.
This device also allows
a TARDIS to jam all but the strongest non-telepathic communications signals.
With the right attachment, a radio communications transceiver (such as a cell phone) can be patched into the TARDIS's communications circuit. This can allow someone with a cell phone to contact a network in another time zone that the TARDIS had previously visited or to interface with local networks in new Time Zones.
A TARDIS can also route cell phone signals through local satellite networks.
However for the augmented radio transmitter to access all of these capabilities it must remain within transmission range of the TARDIS.