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QuantumFx Rotating antenna mmodel ant 105

Discussion in 'General Electronics Discussion' started by mrel, Apr 3, 2013.

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  1. mrel


    Jul 2, 2008
    I have this antenna name QuantumFX its a rotating antenna for television use ( model ant 105).
    Does any body know what type MOTOR is in use in this antenna?
    It has two wires come out from the motor, could not be a Servo motor since Servo motor use three wires or a stepper motor use more than three wires.
    There a circuit board in the case with the motor.
    Can someone explain how this antenna work has control box plus a remote and only one co-axial cable coming from the antenna (in the antenna there circuit board and motor).
    How does antenna turn with one co-axial cable and at same time bring signal to the television?
  2. davenn

    davenn Moderator

    Sep 5, 2009
    Hi mrel

    its a very easy process to superimose a DC voltage onto a coaxial cable at one end of the coax feed and recover it at the other end for use by equipment up an antenna mast.
    In your case a rotator, or others times maybe a masthead RF preamplifier
    The Dc voltage is inserted into the coax using a simple device called a Bias-T and is removed in a similar fashion...


    In the above diagram is another example of needing a DC voltage at the far end of a coax feed. To be able to switch a relay to change the antenna feed being used.

    Lets look at the left side, the TX/RX end ( in my case that is a radio transceiver ... in yours, your TV set). You can see the 12V being applied to the coax via an inductor. The inductor is acting as a RF choke. The series 0.01uF capacitor in the coax line stops any DC voltage feeding into the antenna socket of the transceiver/TV, but passes the RF signal. The 0.01uF cap off the bottom of the inductor to ground, grounds any residual RF voltage that makes it through the inductor so that it doesnt get into the DC power supply

    At the far end of the coax, the right side is a mirror of the other end, the DC voltage is retrieved from the coax via the inductor and is used in this case to operate a relay, in your case a rotator motor the series capacitor stops the DC voltage getting to the antenna.



    Attached Files:

  3. saj


    Sep 18, 2013
    Antenna QuantumFX Ant 105

    Can i modify this antenna to run w/out power? - or - how could I provide power to it?

    The coax leads to a circuit board to amplify and power a rotating motor. That coax cable was cut and the power supply/remote station died - so now, the antenna is in great condition with a new coax cable but no power supply.

    I do not need the rotating function - however, it appears that 'amplification' is necessary although other antennas pull in TV stations w/out amplification.

    Q: Does it really require amplification or can I bypass the circuit board?


    Q: Can I get power to it using a 12V adaptor or other modification?

    Thank you -
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