Video Workshop
CMOS camera
CMOS camera

HF transmitter
HF transmitter
viewfinder
video viewfinder


power supply
power supply
Although conservative kapers prefer discovering pictures after film developing, video monitoring bring important advantages:

  • no more "random" shot
  • no more blurred photos due to camera movements (you can check if the cradle is stable before shooting)
  • possibility to show what is seen from a kite to onlookers
    • Video cameras:
    Purchasing a video camera is no more an issue: many models are available in most electronic retailers. Price depends on definition, miniaturization and BW / color capability. All video camera modules output standard composite video signal compatible with most video monitors or radio transmitters.

    CCD camera
    CCD camera

    Video monitors:
    Several choices are available to the kaper to display video pictures:
  • CRT monitor: either TV set form, or video porter display form. Both can be found in alarm or hardware stores.
  • LCD monitor: several models are available in electronic components retailers. LCD definition is generally lower than CRT, but size and weight are smaller.
    A large sun visor is essential for watching a CRT or LCD screen in the sun.
  • Camcorder viewfinder: very compact and useable in the sun, it is the ultimate for kaping.

    As viewfinders are not available for sale, the only solution is to use a camcorder having a video input (that is not very common), or better pick up a viewfinder from an out of order camcorder.


    Radio control system of the video cradle uses the viewfinder of a JVC GR315S camcorder. This viewfinder has only 3 wired: ground, +8V power supply and video input, so its connection to a video receiver is very easy.


    • CRT monitor
    CRT monitor

    LCD monitor
    LCD monitor
    Video HF transmitters:
    To find a video transmitter in France some years ago was a big issue. But since year 2000, many video transmitter systems are now available.
    Two classes of video transmitters meeting kaper's need can be found in Europe:
  • 2.4GHz FM transmitter/receiver sets
  • PAL or SECAM standard video transmitter

    • In the video cradle, we used a Giga-Link Mini video transmission set produced by the German company VTQ Videotronik GmbH. This set works at 2,4GHz frequency and gives 300m range (10mW power).
    Other main characteristics are given bellow.

    Transmitter Receiver
    Power supply 12V / 100mA 15V / 220mA
    Size with package 54 x 54 x 35mm 130 x 80 x 35mm
    Size without package 45 x 45 x 20mm 110 x 78 x 28mm
    Weight with package 50g 230g
    Weight without package 25g 160g

    Implementation of this transmission set in a kap rig is very easy (antenna is part of the transmitter), and the frequency stability is perfect. Other advantage is that the 2.4GHz working frequency make possible the use of short antennas (< 10cm), easy to implement in a cradle.





    gigalink mini
    Giga-Link Mini

    Our digital cradle uses a KERN subminiature 2.4GHz transmitter. This module has characteristics similar to Giga-link Mini described above, but with an ultra-compact size of 22mm x 15mm x 5mm, a weight of 5g and a consumption of 60ma under 5V.
    In contrast to the 5 programmable channels of the Giga-Link, KERN transmitter has a single frequency, but is compatible with Giga-Link receiver programmed with channel 3.

    KERN transmitter
    KERN transmitter

    The other solution is to implement transmitter modules that output a PAL or SECAM signal compatible with standard TV sets. Italian company AUREL produces a range of such modules. These modules ouput a power of 1mW, so a booster module is necessary to reach 10mW.
    This solution is cheaper than the 2.4GHz one, due to the fact that a receiver is not required (the receiver of the TV monitor is sufficient). But implementation and wiring of AUREL modules is more complex.

    Power supply:
    Implementation of video system often requires 12V power supply in the cradle, whereas the standard voltage available is 4.8V. A solution to generate 12V is to take ten 1.2V AA or AAA batteries, which means 200g with AA or 100g with AAA. An more efficient solution is to implement a DC/DC converter to boost the 4.8V voltage up to 12V. It is possible this way to share the 4.8V battery of the radio receiver to power the video system of the cradle.

    DC/DC booster schematics
    Wiring schematics of the 12V TRACO converter

    The TRACO TEN3-0512, available at Radiospares, meet the specifications above in a size of 32 x 20 x 10mm and a weight of 12g. With a voltage input from 4.5V to 9V, it outputs 12V / 250mA with 77% efficiency. Advantages of such a converter are weight and cost savings (4 AA Ni-CD batteries are less expensive than 10 AAA). Schematics reproduced above are implemented in the video cradle.
    Wiring instruction: to ensure correct working of the DC/DC converter, input and output ground shall be connected together. If not, interference with radio control may occur.

    Conclusion:
    Thanks to large availability of transmission video sets, video monitoring has become far easier to implement for non-specialists. And prices go lower.
    If your cradle doesn't have a video monitoring yet because of complexity, be sure that is no more true!










    DC/DC converter
    DC/DC converter
    Traco TEN-3

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