X-10 Mods - SR731 RF Repeater

Here we explain how to modify a USA 115V SR731 RF Repeater module to operate at 230V.


I have not attempted this modification and accept no responsibility for the effects of anyone making these modifications.   You follow these instructions at your own risk.

This is a report from K F Tai from Hong Kong, who has purchased an SR731 RF Repeater from Smarthome in the USA.  He has successfully modified this unit to operate at 230 volts.

As this is a USA unit, it will operate at the USA RF frequency of 310 MHz.

Modification Steps

Recently I have modified the SR731 RF repeater and it works OK. I just changed:

  • 0.1uF/250V to 0.47uF/400V
  • 100 ohm/0.5W to 220 ohm/1W
  • MOV 125V to 275V

There is a rechargeable 8.4V battery inside the repeater, I have tried to use a 0.33uF/400V and find that the output is only 8V.

When changed to 0.47uF, the output is 9.4V which is sufficient to charge the battery.

If you attempt these modifications, please let me know your results, and read the warning on the X-10 and 115V & 230V page.

Comments received at Redoak

  • KF Tai confirmed the modification worked.

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