FM Transmitter
Sistemas Electrónicos S.A EM 100 DIG
Technical Manual - v1.2 - November 2005
15
The first request it will do will be entering the password for the required level of
authorization/security.The equipment is factory pre-set with the first 2 passwords levels disabled: this
will allow to set most of the operating parameters, including power, frequency, input levels, clock
and date. Some more critical parameters it will require the upper 3
rd
level: be sure to know it if you
need this access.
EM-100 DIG WILL ALWAYS TURN-ON IN THE SAME STATE AS IT WAS IN THE LAST TIME IT WAS TURNED OFF
FROM MAINS,I.E.POWER,FREQUENCY AND EVEN ON OR STAND-BY CONDITION. AS SOON YOU TURN
ON THE REAR PANEL MAINS SWITCH BE PROMPT TO THAT, EVEN WHEN JUST FACTORY DELIVERED.
6 - The first task to manage when turning on the equipment as factory delivered is to set-up the
passwords. At least the 3rd (the highest) level must be immediately changed: because, if any
unauthorized people change it or you lose it, there is no way to change it for security reasons and the
equipment may become unmanageable.
Gaining again access to the equipment will require factory reprogramming or changing of the
internal Microcontroller unit.
For this reason be sure to write down and keep it immediately in a secure place:there is no way to
read it after you have programmed down and confirmed.
For practically any parameters that may require some setting in the field, the 2nd level password is
enough and may be used for any standard service requirement . The main purpose of the
existence of the 3
rd
level is a security assurance for the user if he loses control on the lower password
levels.
7 - If not already done,adjust frequency and RF power as required and check reflected power on the
transmitter's display.
To this aim search for RF power menu and read the corresponding value of direct and reflected
output power.
For proper operation, the reflected power reading should typically be less than 10% of the direct
power value, (<10W max). Any higher reading may indicate that the antenna is not properly
connected or the following amplifier input needs to be tuned.
8 - Check and/or set clock and data and all transmission parameters as required, i.e.channel
sensitivity and deviation, mono/stereo, preemphasis etc. Refer to the appropriate section of the
Manual.
2.3 Audio Base band connections and presets.
2.3.1 Baseband Connection & Wiring and Impedance
Selection.
EM-100 DIG supports balanced or unbalanced signals with selectable input impedance.
The audio inputs are basically balanced and have selectable 600/10k
:
resistive impedance, factory
pre-set at 10k
:
.They can be connected to the balanced output of a professional mixer console or to
the unbalanced one of a cheaper unit without appreciable degradation.
Audio mono or stereo channels inputs are XLR female connectors.They should be connected to the
output of the mixer console, or of any audio processor that drives it, by a balanced coaxial cable