Kite Aerial Photography
Unlike model aircraft flying where the transmitter and joy-sticks are held in front of the operator, with KAP you need to keep your hands, and the space in front of you, free to fly the kite. This means you need to be creative with the equipment. This page describes the ground equipment designed for RIG02 and re-used with subsequent RC control rigs RIG04, RIG05, RIG08, and RIG09 :
The Servo control, or uplink:
This uses standard model aircraft remote control 35MHz technology. Whilst the receiver in the rig is completely standard the joystick control used for aircraft is not suitable for KAP for two main reasons:
Like some other KAPers I got round these issues by building my own transmitter, and housing it in a bum-bag so I can wear it on my back. The bag as shown has three compartments. When worn on the waist the left most (with the aerial) is round my back, the right with the controls beside by left arm, and the central pocket contains the batteries. The flying lead you see is the power supply to the TV receiver - more later.
The transmitter was bought as a kit from Micron which allowed me to customise it to KAP use and make it fit in the bum-bag. The Micron transmitter comes as two circuit boards, but without any joysticks - just what the KAPer ordered!
The picture on the right shows the Micron coder board as finally constructed. From left to right:
Note the cables (multicore) connecting the unit to the battery and the RF module. There are circuit diagrams and layouts for the above parts included in pages 2 and 3 of these details plans .
The picture on the left shows the Micron transmitter board. This module takes the coder board's output signal and turns it into a 35MHz signal for transmission.
Again, looking left to right:
Note at the top of the picture a clamp on ferrite to prevent interference passing between the downlink TV receiver and the Servo Control Transmitter.
The Video viewfinder, or downlink Version 1:
For video Downlink I use the 70cm Amateur Band. RIG02, RIG04, RIG05, & RIG08 transmit a 100mW signal on this band which can be received on a standard handheld TV at the very bottom of it's tuning range. In fact the standard receiver has been modified in three ways to make it easier to use:
To save on batteries (these little TVs eat batteries!), the TV optionally uses the same batteries as the Servo Transmitter as discussed above.
The Video viewfinder, or downlink Version 2:
For video Downlink I moved to 2.4G commercial systems in 2008 with RIG09, transmitting 10mW. The move was triggered by a desire to build a completely new rig from scratch using off-the-shelf components. This also allowed me to experiment with different systems, and leave RIG08 intact. The positive side to 2.4G is smaller transmit aerials, and lighter transmitter, the negatives are less power and more bulky ground equipment consisting on the downlink receiver and separate viewer.
Control of the Kite:
Whilst you can get someone else to fly the kite, or attach it to a fixed point on the ground, the above does allow you to have most of the space in front of you free for kite control, so you can walk about for the best shot, or get yourself out of trouble :-). There is a lot of personal preference here, but I use the following technique: