The IR to RF transmitter circuit given here can convert the IR signals from your remote to RF signals to long distances. The circuit given here is a good one for extending the range of your IR remote.Also such systems does not need a line of sight since RF signals are used.

The transmitter is based on a St-TX 01 ASK transmitter IC (IC2).The IR signals falling on IC 1 (TSOP 1738) will be converted to RF signals by IC2 and transmitted through antenna.The transmitter has a power output of 16dBm at 5V supply.

The receiver is based on a ST-RX04 ASK receiver IC (IC3).The IC3 receives the transmitted code, decodes it to the original IR code and re transmits through IR LED (D1).  The transistor Q1 is used to drive the D1 from the output of the IC3(pin2).

Circuit diagram with Parts list.



  • Use a 6V battery with a 1N 4007 series(forward biased) with its positive terminal as power supply for each circuit.
  • Use  20 cm long  copper wire for each antenna.
  • Ranges upto 200m are possible with matching antenna.
  • The capacitor C1 must be rated 10V.


  1. This TWO parts are available at kolkata chandni cwawk.

  2. This circuit will NOT work. TSOP1738 receiver will demodulate the input from your remote and feed the transmitted code to ST-TX 01 ASK transmitter. But the ST-RX04 ASK receiver will only process the transmitted code. The code will need to be modulated again with a 38 KHz signal before sending to IR Led. The modulation is missing here.

  3. Patil Mahesh

    we also tried but in vain its not working at all…

  4. Any one can tell whr we will get ic sttx01 & strx04 in India esspeacially in karnataka

  5. Plz give me the details of each component of this ckt

  6. i try this circuit it is not working admin says one small problem in this circuit sir please tell where the problem

  7. TSOP ,is an IR decoder,so the output is not a bunch of pulse burst with duty cicles that an remote are emitting.
    This means , the TSOP inside of the TV have to decode an already decoded signal.
    soo I think this is not working.
    Has anyone tried this schematic?

  8. What are the replacements for ST-RX04 ASK receiver?

  9. Seetharaman

    You may have to contact the manufacturer for the product, not available in India.

    1F., No.16, Lane 32, Sec. 1, Wunhua Rd., Banciao City, Taipei County 220,Taiwan(R.O.C.)



  10. Sahajahan

    Plz someone tell me
    what is the ic numbers of ic3 and ic3

  11. Admin Sir,
    How do we use the transmitter? where do we press or use some sort of switch?
    How can we buy the I.C’s, it is very hard to finde hgere in Kuwait.

  12. john bharath

    the idea is good but cant used as ir to rf to ir extender ,where the ir has the data but no carrier freq because all ir decoder sensors decodes for the carrier freq Ex:40khz,38khz,36khz it requires a carrier freq gen for tx the data again.

  13. Did anyone every try this circuit and if this worked properly?

  14. rf remote extender

    Great Post! I personally really appreciate your writing. This is a great website. I will make sure that I stop back again!.

  15. deepthought

    Did you test this circuit? I wonder that it should work without any signal modulation after IC3…

  16. In IR to RF converter what is the IC no. of IC2(STtx01)& IC3(STRX01)?Plz rply

  17. IR to RF converter circuit. What is the ic2 IC number
    pls reply me.

    • admin

      oops! that was an error in he circuit diagram.
      now corrected.pls check the circuit.

      thanks for pointing the error.