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Keying Relay Circuit Kit

Keying Relay Circuit Kit

SKU: 217537123517253

This T/R keying circuit kit (also known as a Carrier Operated Relay circuit) is used for automatic switching between receive mode and transmit mode. The kit includes all the necessary parts for most RF Linear Amplifiers used for Ham Radio. The PC board is professionally fabricated and is designed to produce reliable operation. The relay is rated for 30 amps and has a lower impedance when compared to other relay designs making ideal for RF aplications. The RF sensing circuit is designed for the High Frequency Band and supports AM, FM, and SSB operating modes. Typical designs use a small signal transistor to turn the relay coil on and off. This new design employs an opto-coupler which provides complete isolation between the RF single and the 12 volt DC supply. The advantages are less RF signal to trigger the opto-coupler and virtually no interaction between the RF signal and the 12 volt source. This topology offers high reliability with no false switching or relay chattering. The board dimensions are 2.5" wide by 3.5" long. Units ship with schematic and detailed assembly instructions. I also provide free technical support by email.

  • Operating Voltage 12 to 14 volts DC
  • Current Draw 100 mA
  • Relay Contact Rating –  30 Amps
  • Power Rating 2000 watts RMS 3000 watts PEP
  • Input Power Required For RF Sensing - 0.5 watts Min.
  • Operating Modes – AM, FM, SSB
  • Frequency Range - 1.8 to 54 MHz

This is a kit as requires basic soldering skills for assembly.


  • Shipping Info

    Add $24.95 to ship to US Main. Ask for quote for international shipments.

$84.95 Regular Price
$64.95Sale Price
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