FM TRANSMITTER
TR
EM
1000
HE
DIG
PLUS
COMPACT
Technical Manual 1v2 November 2019
24
5) The input impedance is easily set using the
JP1
e
JP2
jumpers found on the input card,
immediately after the input connectors as illustrated in the design. The selectable impedance
values are serigraphed on the printed circuit board.
6) Place the top cover back on the transmitter, ensuring that all the screws are correctly
screwed into place.
2.1.7 Pre-emphasis
The low frequency audio signals of mono and stereo channels must be properly “pre-
emphasized”. The standard pre-emphasis is 50 or 75μs, the first value usually being the one
selected during manufacture. Confirm that this value is appropriate in your country: it is the
standard value for all countries in Europe, most of the Pacific regions, and some countries in
South America. However, the North American FCC standards require 75μs.
To make changes to the pre-emphasis, use the
SETUP
menu.
2.1.8 Operating with the RDS and SCA encoders
In addition to the aforementioned operating modes, this device is able to transmit an auxiliary
signal (RDS or SCA) connected to the rear
AUX
terminal as follows:
1) Connect the
AUX
terminal to the RDS or SCA encoder output.
2) If the internal stereo encoder is used, connect the
MODULATION MONITOR
output to the
“driver tone” synchronization input on the RDS encoder (where available).
3) Using the
SETUP
-
AUX SENS
menu, change the channel input sensitivity and, where
necessary, the external generator level so as to obtain the required deviation. For RDS
encoders, a reading of -11.5 dB or 2kHz is the standard modulation value.
4) Modulation and deviation can be viewed on the
STATUS
screen, in addition to any other
multiplex signals available at that time.
If the length of the cable delivering the signal to the AUX terminal is only a few meters long, a
50 Ohm (RG58) cable can be used. If the distance is greater, a 75 Ohm (RG59) or 92 Ohm
(RG62) cable should be used. The same is valid for connection to the MODULATION MONITOR
input.
