RDS Encoder

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This dynamic stand-alone RDS encoder is ideal for use in RSL or small FM radio stations. Simple and modern concept of the RDS encoder uses two programmed microcontrollers for clock and data stream generating. Spectral purity around the 57 kHz subcarrier is very good due to digitally generated modulation signal using D/A converter. This distinctive feature permits the RDS encoder to be free of any bandpass filter. The spectral purity is assured in a digital manner. Number of RDS services supported makes this device akin to professional equipment.
Physical characteristics of the output signal are configured on the RDS encoder’s board. Other features are controlled by software through parallel port. In addition to basic functions the control software gives the RDS encoder many advanced possibilities.

• Dynamic stand-alone RDS encoder
• Excellent spectral purity
• MPX loopthrough
• Internal clock — Stand-alone CT transmission
• Additional pilot lock circuit with phase shift adjust

(The RDS services are described in Support)

Text capacity:

• 64 Dynamic PS labels + Default PS + Traffic PS
• 2 Radiotexts

Supply - Power supply connector
1: + 8-25 V
2: ground

PLL - Additional pilot lock circuit connector
1: +5V out
2: 57 kHz out
3: 57 kHz in
4: ground
(Note: If the pilot lock feature is not required, short pins 2 and 3 using a jumper.)

TA - External TA switch
Open: TA=0
Short: TA=1

Input - Audio/MPX input
1: input
2: ground

Output - Audio/MPX + RDS output
1: output
2: ground

Parallel port - Parallel port interface
1: clock, pin 7
2: send enable, pin 12
3: data, pin 8
4: ground, pin 25

LED - Function indicator

Level adjust - Output RDS signal level adjust

To do this you need a 25 pin D-SUB male connector and several meters of four wires cable. (Optionally, if the encoder is placed into a case, you can use a DIN connector on the panel so the cable needn't to be fixed to the encoder.) Connect corresponding pin numbers on the D-SUB connector and the cable is done. Now you can control all the RDS features by the software.

It's also possible to use 25-pin D-SUB connectors on both side and use standard parallel data cable for connection.

The parallel cable layout

Following pictures show various situations and corresponding methods of connection:

Mono transmitter and mono audio source. The easiest event.

Mono transmitter with external stereo encoder

Stereo transmitter with RDS input.

Unfortunately some manufacturers don't equip the stereo transmitter with RDS input. They probably forgot that the RDS exists...
If a stereo transmitter is used (as in previous case), but it has no RDS input, an encroachment to the transmitter is necessary. Find a varicap (capacitive diode) in oscillator and connect the RDS input connector by the following diagram. Then fix the connector in front panel of the transmitter.

In some cases it's necessary to fetch out the 19 kHz pilot signal from stereo encoder or stereo transmitter if the equipment doesn't have this output. This is always possible, but there exist many kinds of used circuits. It's difficult to describe any general way.
For example, the BA1404 circuit has 19 kHz output on pin 13, which can be connected directly to the PLL circuit.
In the worst case, the RDS encoder may be operated without PLL function configured as with mono transmitter and mono audio source.

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