Minute sound hearing micro transmitter by remote control
KRT-400T

Outline
  • The (KRT-400T) is the smallest and epoch-making transmitter in the world in which a device of voice transmitter and control signal receiver is built.
  • Only install the transmitter in setting the power supply switch "ON" at a place to catch sound. An electric wave does not always release and it begins to send wave upon receipt of instruction signal to "Start" from the remote control receiver (KRT-400R). Set the switch "OFF" on the receiver, then, stops to send wave automatically by which extra wave is saved.
  • The available distance is about 200 meters in use with an exclusive remote control receiver. The battery life is 2 days and a half in continuously transmitting but it is extended to 15 days under the condition that is intermittent releasing. In other words, the battery life is available for 10 days if monitor 1 hour per day.
  • The battery adapter (AD-RT) is available to extend the battery life by 30 times and enable to control operation for "Start and Stop" automatically in connection with a Surveillance camera, a Video transmitter and other electronic devices driving with batteries placed outside.
  • Although the number of standard articles is C channels, arbitrary frequency can be manufactured if it is between 398.5Mhz or 399.5Mhzes.
Direction
  • If the both-sides side of the battery lid of the back rear is pressed down so that it may pinch by the thumb and the index finger, and it is slid back, the battery wearing place of a battery is visible. It is careful of polarity to prevent mistakes. The dry cell of U5 is used two If an alkali dry cell is used, it can use for a long time.
  • An attached helical antenna or an attached whip antenna is put in the antenna terminal of the front of a main part. Subsequently, knob of a small slide switch written to be "ON, OFF" of the side It moves in the direction of ON. It will be in a state of operation now. As for electric wave efficiency, in about ten percent, the direction of a whip antenna becomes good.
  • A remote control receiver and a two set set use as a remote control transmitter. In a standard article, an internal transmitter becomes only C channels [ one ]. If a remote control receiver is power supply switched on, it will begin and for 2 seconds will send an instruction electric wave to the receiver by the side of a remote control transmitter. The internal-organs receiver by the side of a remote control transmitter is operating a short time at intervals of 2 seconds, in order to save a battery. Therefore, sending an instruction electric wave only at the beginning which turned on the power supply switch is continued for 2 seconds. Perception of it of the internal-organs receiver by the side of a remote control transmitter begins to send an electric wave. Although the oscillation electric wave by the side of transmission is henceforth disconnected at intervals of 4 minutes, the direction of a remote control receiver side will issue instructions of re-connection at an instant, if the electric wave by the side of transmission is disconnected. Therefore, unless the power supply switch by the side of a remote control receiver is turned off, it can continue receiving continuously. If the power supply switch by the side of a remote control receiver is turned off when stopping, dispatch of the electric wave by the side of a remote control transmitter will also go out automatically less than several minutes.
  • When carrying out intermittence control of external CCD camera, an external image transmitter, etc., it is used by putting the shield code with a plug in the jack by the side of a power supply switch (option). It connects with the ground side of the apparatus which connects a central line to the minus side of the power supply (battery) which supplies a shield side to the apparatus. In this case, once it cuts the line by the side of the power supply currently supplied to apparatus from the apparatus, it is connected with the disconnected power supply (minus side of battery) side. It cannot use in a plus side. A minus side is surely used. In this case, the case of the apparatus controlled with a remote control transmitter must be in the insulated state mutually. The current which can be intermittent is to 400mA in the maximum. Voltage is 20VD.C in the maximum. A.C Line cannot be used.
  • When carrying out automatic recording combining a commercial recorder, it is used by putting the recording code of remote control receiver attachment in the earphone terminal of a remote control receiver, and the external microphone terminal of a recorder. A receiver, a recorder, and cases are put together and it is made not to install. When used by sticking, placing in between etc. should carry out, insulate and install paper, a cloth piece, etc. Unless cases are insulated, it may not be recorded normally.
Specification of KRT-400T
    Receiving part.
      Receiver (double superheterodyne system 1ST:10.7Mhz 2ND:455Khz).
      Receivable frequency for narrow-band FM C channels 399.030Mhz.
      Receiving sensitivity 0.3microV (-117dbm) S/N 20db.
      Antenna impedance 50ohm.
      Consumption current About 0.4mA (at time of standby).
    Transmitting part.
      Narrow-band frequency modulation type.
      Transmitting oscillation frequency C channels 399.030Mhz.
      Maximum frequency deviation +-10Khz.
      Consumption current 9mA.
      High frequency output 5mW.
      Sprias Less than [ -50db ].
      Antenna output impedance 50ohm.
      Frequency stability Below +-5 ppm (-10 degree-C ~ 50 degree C).
    Remote controling part.
      Consumption current 0.5mA.
      Transmitter cutting timer About 4 minutes.
      Re-connect time Less than [ 50mS ].
    External apparatus connection capacity 0.4A 20VDC Max.
    Antenna 50 ohms RCA jack a helical -- or 1/4 wave form memory strait-wire (18cm).
    Power supply voltage 1.1V ~ 3V Stabilization step up circuit internal organs (two U5 is used).
    Battery adapter AD-RT (option).
    Operating temperature -5 degrees C ~ 50 degree-C.
    Weight 32g (without battery).
    Outside size 14mmx73mmx26mm without Antenna.
    Manufacture in the range of 398.5Mhz ~ 399.5Mhz is possible
            for a custom-made item (channel interval 20Khz).
Notes
  • When not receiving, the switch of a battery is surely turned off. When you do not use for a long period of time, please take out a battery and place it. Internal parts are damaged when a battery carries out a liquid leak.
  • Since the inside consists of precision parts, please do not drop it, or do not apply power which is twisted strongly. It carries out as carefully as possible, the desorption of an antenna also having both sides for a root portion with a finger, and turning to right and left little by little slowly.
  • Please do not attach a powerful magnet to a main part. It stops functioning at an instant like a magnetic card. It does not return, unless it readjusts.