(Fully Assembled)


(click picture to enlarge)

This assembled four channel RF Remote Control Relay Board is an improved version of our original CK1616 unit and is similar to our HD2RX but with 2 additional channels.  It uses an auto roll algorithm which makes it almost impossible to steal the code for unauthorized use.  It has 4 relays (channels) that are individually jumper selectable as either latching or momentary.  Each channel has a reset connection, so you could use a limit switch to reset the relay if you desired.  Each channel has led indicators.  Receiver can support up to 6 transmitters.  This unit makes remote control very affordable for you next project.  


  • Range is up to 250 feet.
  • Transmits on 433.9 MHz
  • Transmitter includes battery.
  • Receiver Power 12 VDC (power supply not included)
    (Need a Power Supply?)
  • Circuit draws 10mA in idle state and 4 relays energized draws 120mA.
  • Relays have a Common, Normally Closed (NC), and Normally Open (NO).
  • Each relay has a reset wiring option for use to reset the relay with a limit switch.  (i.e. Garage Door Opener, set relay to latching mode, relay is energized powering door motor, door trips a travel limit switch that is wired back to the relay board turning the relay off.)
  • Each Individual Relay is jumper selectable latching or momentary. 
  • Up to 6 transmitters per receiver board.
  • Relay Contact Ratings: 24VDC@10A, 240VAC@7A, 120VAC@10A. (more info on how relays work)
  • Transmitter Dimensions 2" L x 1-1/2" W x 1/2" D
  • Receiver Board Dimensions 4" L x 2-7/8" W x 3/4" H

Click for a typical wiring diagram for relay.

CLICK HERE FOR INSTRUCTIONS ON USING THE HD4RX.  Requires Adobe Acrobat Reader available at www.adobe.com for FREE!

Note: This is an assembled and tested unit.  This unit is not compatible with any parts from our CK1616 unit.

HD4Combo - (1 Rx & 1 Tx) $37.95
HD4RX - (Receiver Relay Board) $29.95
HD4TX - (Transmitter Only) $12.95
(note: These devices are not compatible with our CK1616)

Click here to see our 2 channel version of this board

Quantity and Educational discounts?


E-Commerce Solutions

Electronic Kits

    Our Secure Shopping Cart allows you to MAIL, FAX, CALL, or PAY ON-LINE! - Toll Free Orders Call 866-664-0627 or 510-451-4320 (Non US), FAX - 510-903-9712

More Great Electronic and Robotic Products From Electronic Kits  Follow electronickits on Twitter

New! - OWI Eco Biker Wind Powered LED Light Kit - $11.95

Mini Solar Kits - Many to choose from - $8.95 and up

BIOLOID Humanoid Robot - all versions - WOW!

Humanoid Robot Kit


6 in 1 Solar Educational Kit - Sale - $16.95


OWI535 Low Cost Robotic Arm Trainer - NEW!

Sale! - $47.95

KeyKatcher Keyboard Data Loggers - ON SALE NOW!

Computer Security

Solar Science Projects

Solar House Science Fair Project

Solar Power House Kit - $134.90

[New Products] [Electronic Kits] [Electronic Plans] [Robot Kits] [Computer, Security, Gadgets] [Test Equipment] [Satellite] [Cable] 

[Home] [About Us] [Policies/Terms of Sale] [Order] [Catalogs] [Quantity & Educational Discounts] [Links] [Gift Certificates] [Join Our Affiliate Program]

Carl's Electronics
484 Lakepark Ave, Suite 59, Oakland,CA  94610
(866) 664-0627 toll-free USA
or (510) 451-4320
(510) 903-9712 fax    


Copyright 1995-20012 Carl's Electronics Electronic Kits dot com