Genesys GDR- COM Series, Installation Manual, Page: 36 / 62

GDR-XXXX NAV/COM INSTALLATION MANUAL
CHAPTER 2 – SYSTEM INSTALLATION
64-000109 Page 36 of 62
Conn Pin Description
P1 2 S
P1 3 SIDETONE-
P1 5 UHF AUDIO-
P1 6 UHF AUDIO+
P1 13 VHF AUDIO-
P1 14 VHF AUDIO+
F. PTT and TX INTERLOCK
The VHF and UHF transceivers have separate Push-To-Talk (PTT) inputs, except
when configured for single radio mode. Each PTT input has an impedance of 7.9k
Ohms and requires a voltage below 2.0 VDC to be active.
The Transmit Interlock discrete input is available in installations where a co-located
transmitter’s noise floor opens the receiver’s squelch during transmit. This can
occur when COM to COM antenna separation is limited. If this occurs, all
receiver’s TX interlock may be diode ORed with the PTT to the audio panel. This
feature is also available in select audio panels.
When the Transmit Interlock input is pulled low, this inserts a 10 dB pad at the
input of the COM receivers and enables the TX Squelch level settings. This
reduces the sensitivity of the receiver during transmit and allows an alternate
squelch setting during transmit when required. The need for this feature is
determined by the location of antennas and the noise floor of the offending
transmitter.
CAUTION: The TX Interlock pin of all radios cannot sink any current otherwise TX
Interlock will be permanently active unless an external pull up resistor
is installed.
Conn Pin Description
P1 4 VHF PTT
P1 12 UHF PTT
P1 15 TX INTERLOCK
G. NAV and MB AUDIO
The NAV (VOR/LOC) and MB receivers each have separate balanced audio
outputs. Each output can generate 100 mW into a 600 Ohm load at 7.75 ± 0.5
Vrms. Normal production setting is for 100 mW into 150 Ohm load at 3.87 ± 0.5
Vrms.
Conn Pin Description
P2 20 NAV AUDIO-
P2 23 NAV AUDIO+
P2 24 MB AUDIO+
P2 25 MB AUDIO-