Maintenance Manual

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©2021 Broadcast Electronics
Pin 6, RF enable input. Base input of a common emitter transistor with a resistive pull-up.
A shorted circuit to ground disables RF. Maximum voltage and current available are roughly +10V
and 1mA.
Pin 7, Alarm output. Open collector transistor circuit with a resistive pull-up: logic low
signal means alarm condition. Correct functioning is signaled by +12V with10kimpedance.
Maximum current sinking capability <10mA.
Pins 4 & 9 Reserved for future upgrades.
GRX Parallel Remote
Pins 1 & 5 Ground.
Pin 2, “Modulation OK” output. Open collector transistor circuit with a resistive pull-up: a
low logic state signals modulation is present on the received signal. On the contrary, a high logic
state, + 12V / 10kOhm, warns on modulation loss. As alternate function the pin may be assigned to
signal “remote lock” status.
Pins 3 & 8, “Field Good”. The insulated contacts of a relay are wired to these pins: the relay is
default driven by the received RF. When the field exceeds the preset threshold, the relay is excited.
The contacts may be chosen through an internal bridge to be "normally open (n.o.)" or "normally
closed (n.c.)". Factory default is "n.o.". Alternatively, the relay may be assigned to “Alarm”
Pin 6, "LF Disable" input. Base input of a common emitter transistor with a resistive pull-
up. A shorted circuit to ground disables main LF outputs. Maximum voltage and current available are
nearly +10V and 1mA. Alternate function is “Remote lock”: when chosen, a shorted circuit disables
front panel setup functions.
-Pin 7, “Alarm” output. Open collector transistor circuit with a resistive pull-up: a logic low
signal means alarm condition. Correct functioning is signaled by +12V with10k
Ω impedance.
Maximum current sinking capability <10mA. This pin may be alternatively assigned to signal “Field
good”
-Pins 4 & 9: Reserved for future upgrades.
Battery or DC Supply
The Marti GTX/GRX include a low voltage d.c. power supply input with battery management, to
permit continuous d.c. power supply or back-up in case of mains failure. This input, whose nominal
voltage is 24 V negative grounded, accepts a dc supply which may range 22 - 28 V in absence of mains
supply. It delivers a regulated +27.6V to permit battery charging, when mains supply is present.
Front panel switch do not acts on d.c. supply, which is always on when applied to its terminals on the
rear panel. There is no switch in series to this supply but only a diode and a self-reset fuse to protect
from polarity reversal.
Voltage higher than 28Vdc applied to or current sunk from this input for different purpose than
battery charging may seriously impair the equipment power supply.
3.5.1 Notes on battery and wiring
Any kind of battery may be used, provided it has the correct voltage (24 V, nominal) and an adequate
capacity. Price / performance considerations may suggest plumb batteries, regular or sealed.