THE RXD433
This wireless RF receiver/decoder has a 4 bit data output that will match the data sent by the encoder, TXE433. The output is CMOS compatible when the unit is run on +5 volts.
The demod bandwidth is selectable by the placement of jumpers on the circuit board. The table on the schematic shows jumper positions for different bandwidths. Narrower bandwidths will give slightly better range at the expense of more limited constraints on battery voltage tolerance over time and more limited operating temperature range. For most applications, the 4800 Hz setting will be best.
The “decoder address select” allows you to use one transmitter to control different receivers by giving each receiver a unique address. The decoder chip has internal
The receiver/decoder unit additionally has a “data valid” output. This output goes high when the “decoder address select” matches the encoder’s address select. This is convenient place to connect a “data valid” LED indicator to show at a glance when the receiver is decoding. The schematic below shows how such an LED can be connected.
ANTENNA CONSIDERATIONS:
The simplest antenna consists of a piece of wire approximately 6 to 7 inches long. If you desire more range you can try a ground plane antenna or a Yagi such as the Ramsey 4004 model. The antenna should be tuned for the 433 MHz band for best operation.
