Operation and Installation Manual
KRT2 VHF-Communication Transceiver
Doc.-No: KRT2.A-MAN.en
Rev. 0101
Page
35
6.7.1 Microphone connection
Both the L (left) and R (right) microphone input channels can either be connected to standard micro-
phones (standard signal level 1Vpp) or to dynamic microphones (standard signal level 5mV to 10mV).
Input R has less sensitivity (30mV).
For standard microp
hones a supply voltage of 8V at 330Ω is provided.
Elementary Electret microphones can also be connected. They have considerably lower signal levels
and therefore require an 8V supply voltage.
The microphone input channel amplifier gain can be selected via the MIC-Setup menu “4.4.11 MIC –
Setup”.
When dynamic microphones are used in gliders the 8V supply voltage is switched off for power saving
purposes.
Standard microphones normally used as in headsets, together with dynamic microphones generally
cannot be used at the same time, but instead alternatively. If input R is not used it should be loaded or
grounded and not be left unconnected.
Motor gliders should have a toggle switch installed to differentiate between motor less flight with dy-
namic microphones and powered flight with headsets.
When the AUTO mode is selected in the MIC-Setup menu the KRT2 automatically recognizes on
MIC-L (pin 3) which microphone type has been switched and acts accordingly.
Both inputs (L and R) must not be wired together. L is the master input.
Figure 6: Headsets
