Refining the system

On first inspection this looks like a right lash -up, and in many ways it is! Underneath all the gubbins is a ‘standard’: Futaba T4EXA 4 channel 35mHz radio control transmitter. I have decided to see if I can get the ground gear for KAP into a single ‘unit’ running off a single power source. The trigger for this madness was the sad demise of my last 2.5″ LCD screen on my travels to Flanders, I crushed it in my bag and it was never the same again. The screens are cheap but that is no consolation when about to commit the camera to the air and discover the lack of a ground view. So there it is: the mk2 configuration with ‘system integration’ achieved by winding half a roll of electrical tape around the components.

The big discovery was that I could power a RangeVideo reciver (on the left of the photo) unit off the Futaba Tx battery, it says it requires 12v but investigation by experts relevals it will accept 5-12v, A Y cable off the battery gave me an unswitched supply of 11-7v.

That’s a live view on the monitor, James Gentle’s altimeter shows an unzeroed 73m.

The mods list now looks like this:

1. Antenna: replaced with a bayonet demountable replacement to allow for transport and field survival. These things break very easily and, because the transmitter needs to radiate as efficently as possible to balance the video transmitter at the rig end, replacement with a stub is not an option. To avoid loss of the antenna whilst dancing about chasing string a lanyard secures it to the transmitter neck strap.

2. Power supply, the 8 AA cells are replaced with a single Ripmax rechargeable 2700mAh pack.  A ‘Y’ cable shares the current with the reciever. Field trials have shown the voltage holds up fine for at least 3hours powering both units, I expect to get at least double this given the performace of the battery thus far.

3. Video reciever, this is taped onto the tranmitter, and, despite the econonmy of sharing power with the transmitter it is quite heavy thanks to its fancy metal case.

4. Video monitor, in this trial configuration it is self powered by its own rechrageable 3.7v battery adding yet more weight to the controller. I am advised it is rated at 5v, which suggests it might share a supply from the video reciver. It is attached by a strap with click-shut buckle to the controller. I now remove it after use and pack it carefully in the camera box to preserve it.

Next steps are to strip out the boards, devise a voltage regulated supply for the screen,  get a single ‘on/off’ swich for the 3 components and then open the tranmitter case and try to stuff all the bits in. The objective is to get the reciever and the screen in the same case as the controller in the hope that it will travel better and reduce the battery charging hassle.

How hard can it be?

More on RangeVideo here

About billboyheritagesurvey

Heritage worker
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2 Responses to Refining the system

  1. Ramon says:

    How hard can it be… Not that hard, but I myself need to clean up my own configuration which looks about the same as yours. My plan is/was to only use the necessary parts from the R/C transmitter and put them in a new case, together with the video receiver, the LCD and the battery or batteries. I almost have all parts but the case and then it’s only a matter of planning. And time…

  2. jokerxl says:

    Loving the “Heath-Robinson” -ness of this. I bet it works great!

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