Tuning the Super-Regenerative Receiver
For X10 Home Automation RF Receiver Applications
Most X10 transmitters are LC tuned and do not work too well with Super-Heterodyne receivers because of their frequency
drift. Super-Regenerative receivers, on the other hand, provide very good sensitivity and have a wide frequency
bandwidth making them the best choice for X10 RF.
Here are two low cost, readily available 315 MHz receiver modules that can be easily tuned to 310 MHz.
| Tuning the Super-Regenerative Receiver to the X10 RF Frequency of 310 MHz |
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Power up the module with a 5-volt supply and no antenna attached. You will adjust the
coil tuning slug for maximum signal amplitude. A scope
would be best or use the circuit above with a voltmeter.
The signal test point is at the junction of the IC Pin 3
and the 200K ohm resistor. It is the received signal before
the "data slicer". While transmitting a continuous signal
from an X10 RF wireless remote, and using a non-metallic tuning
tool, adjust the tuning slug counter clockwise nearly
1/2 turn until the voltmeter reading reaches maximum.
At close range, the reading will be about 2.7 volts.
Move the transmitter further away and adjust for the
final maximum voltage reading.
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