The View Up Here

Random scribblings about kites, photography, machining, and anything else

Closer on the Video Downlink

Posted by Tom Benedict on 30/12/2011

Sorry, no pictures yet. But I did finally test all the hardware end-to-end. Egads what a wait! Thankfully, everything worked great first try.

The cabling on the KAP rig is done. Except for Velcro to hold the video transmitter down, it’s ready to fly. Since I hacked the Hobby King transmitter to take the video gear, this involved changing the RC receiver as well. The antenna wiring on the Hobby King receiver is cleaner than the antenna on the Turborix receiver, so I don’t really mind. It’s a good change. The only thing I’m not 100% happy with is the 9V battery held on with Velcro strap. But for now it’s what I’ve got. I figure I’ll fly this way maybe two or three times before I get frustrated and change my rig’s batteries out for a LiPo or LiFe. (Thanks, Bill, for pointing me in that direction!)

I still have some work to do on the ground unit. The only really big one is changing out the DC power cable that drives the video receiver. The 5.8GHz unit uses a different plug than the 900MHz one. No biggie. Just two solder dots and it’s done.

I even made a screen shade for the transmitter out of some ABS plastic I had lying around the shop at home. A quick trip through the bead blaster at work and it even has a matte texture on the inside!

The last outstanding grumble on the ground unit is the ugly UGLY mess of video cables that go between the receiver and the monitor. When I wired everything up I had to laugh. The wad of cables is actually bigger than the receiver and monitor put together! UGH! But I’ve got some connectors on order that should let me build a custom cable, and clean up the mess. Meanwhile I’ll fly with the wad taped to the back of my ground unit.

Now for the good part:

The video was gorgeous. The refresh rate is extremely fast, so it’s dead nuts easy to see if the camera is stable or not. The monitor is actually larger than the LCD on the back of my camera, which is great. My eyes aren’t what they used to be, so the bigger the better. And since I have to run the camera in live view mode in order to use the video downlink, I get to see my focus spot, whether it has achieved focus or not, the shutter speed, aperture, EVERYTHING! Camera telemetry!! (Can you tell I’m excited?)

I admit. I’ve got the giddies. But a cautionary note from Bill Blake keeps rattling around in my mind: Yeah, this is neat and all. But essentially I just added a whole ‘nuther person worth of work to my setup. In addition to keeping track of the kite and of the rig, now I have to keep track of a viewfinder. It may be more trouble than it’s worth.

(But I really hope not!)

Should be a fun weekend.

– Tom

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2 Responses to “Closer on the Video Downlink”

  1. Yaniv said

    Consider adding a future GPS tracker in case that your rig will land beyond visability point (i.e. If a kite goes down unexpected).

  2. Tom Benedict said

    So far that hasn’t been a problem with me. I’m not saying it won’t be in the future, but so far… (knocking on wood)

    I rarely have my camera more than 300′ from where I am. The kite will of course be a little farther. One of the unfortunate characteristics of this place is that if my line breaks at the winder, there will either be lots of things to snag it and keep it from flying away (kiawe trees, lava rock, etc.) or nothing at all (open ocean all the way to Antarctica). On the one hand I can typically retrieve it within an hour or so. On the other? “Darn” about covers it.

    Tom

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