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KeithLuneau

Cheap 1.2GHz Hong Kong cam working like a charm

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For the impatient, skip to the bottom for the video link!

Hi, just thought I'd drop in and say thanks to everyone who helped when I had questions a while back. I bought one of those "Ebay special" imported cams, sold as a 200mW 1.2GHz camera, and it's anything but. Like this - http://www.rc-cam.com/hk_video.htm

After building the GPP scaled to 1.16GHz, cutting the voltage regulator out of the heavy plug and wiring up a smaller one, powering with an 8.4V NiMH battery, etc. I could get a useable range sometimes, but the image quality was horrible. See more on that here - http://www.rc-cam.com/forum/index.php?show...owtopic=508&hl=

I'm happy to report that after deciding to dig the camera out of a box of junk it was calling home, I was able to solve all it's problems with a few more simple mods. I had started wiring the transmitter to use with another camera, and ordered a CCD camera which never showed up. Supercircuits offered to re-ship or issue a refund, I chose the refund and just dropped it, forgot about the whole idea. So the other day I took it back out and finished wiring the transmitter up, and decided to wire the camera to plug into it just to play around some more while I looked for a better camera. I kept seeing people talk about covering a portion of the CMOS sensor with electrical tape to stop the ugly colors. So, I followed one guys method of taking the front of the case off, and powering the camera up, then positioning the tape on the sensore so it's just outside of the display on the screen. This seems to have worked wonders!

I'm using a standars F-connector on my receiver antenna, and have read multiple times that standard coax cable is far from the best solution here. I was using a piece about 3 feet long. I decided to fix that too, and made up and cable as short as I could get it, about and inch and a half long. it's rigid enough to support the antenna, so I mounted the receiver on top of a tripod so that it's easily portable, and gets the antenna off the ground. It's easy to adjust the angle of the antenna as well.

I also added a piece of wire on the transmitter antenna to make it exactly 123mm long as suggested on the HK Video page above.

I'm not sure what change had to most effect on range, but I was flying a Schoolboy .09 converted to cobalt 400 power, and specked it out and had very minor drop outs. The tape trick seems have been the key to the color issue as well.

So I can finally say that this setup is working FAR beyond what I ever expected to get out of it. The good part too, is that it's just a matter of plugging in another video source now, so I can make up a cable to downlink the video out from my still camera for those AP runs.

If you can't tell, I'm very pleased with what I've been able to get from this often thought of as worthless camera!

Now for the good part, the video. Look for SBCam.wmv about halfway down this page: http://kluneau.rchomepage.com/AP.html

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Could you explain with some details how to put the electrical tape in the cmos sensor? I´m having the same problems with my ebay camera setup, I´ve already perfommed a big advance in the range.

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It's not that hard to do, you basically need to cover the right side (when looking at the front of the sensor) so that the tape is just outside the viewavle area. I took the front half of the case off, and then powered the camera up. It gives you a sort of white screen with no lens, and makes it easy to see where the tapes comes into the edge of the screen. Lay the tape on the sensore but dont stick it down, and move it towards the middle until you see it come into the edge of the screen then pull it just outside of the screen, and stick it down there. Be careful not to touch the surface of the sensor if you can help it, and if you do or if there's dust on it, a cue tip damp with alcohol or glass cleaner seems to work well enough to clean it off.

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