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The test system's AHD vTx and camera are mounted on a 3D printed chassis. It is inconveniently bulky (3.5 x 4 inches, 4.3 ounces). The ground station is also mounted in a 3D printed chassis; It consists of the AHD vRx, AHD-HDMI video converter, and HDMI recorder. Here's what it all looks like: The vTx's large form factor is not ideal but fortunately not a major issue at this point. Plus my randomly chosen parts have performance issues too (prolonged black screen drop outs, some color shifting, etc.) Non of this matters yet because for now I'm only evaluating the video resolution versus traditional analog FPV. So I don't mind that my test system is a quirky Frankenstein monster. Basic ground tests gave me a preview of what to expect. The recorded FPV downlink video shows that image resolution is better than a standard FPV system. It's also in a native 14:9 screen format instead of the typical 4:3 format. So far so good! The video also has examples of the black screen dropouts caused by the AHD-HDMI adapter. There's also random color shifting caused by an out-of-spec colorburst amplitude. But these things can be fixed by the future developers that understand the potential of AHD FPV and build us an our dream system. What's next? With the ground test out of the way I'm now ready for a quick test flight. Should be ready to fly with it next week if the weather cooperates.
- Last week
Ok, thanks for the info. Adding the internal piece of coax will be a project for this weekend. Not sure about building an antenna at this time. Might look at a mobile antenna for 6 meters for now, since I already have the mobile mount, and see how well it works just with the magnet base on a flat metal bar. Another issue that came up in testing is rfi from the solar panel / battery setup at the rx location. Seems the cheap charge controller I was using created a lot of noise. Once I had the tx a far enough away from the rx, the rx wasn't responding. Didn't realize noise was the problem until I hooked the rx and control circuits directly to another battery. Have a Morningstar controller that I'm switching out in hopes that reduces any interference. Also, need to clean up the rats nest of wires between the rx and the control circuits. Next would be some chokes, but need to figure out values to use. Thanks again for the help. Mike
hippyengineer replied to Mr.RC-Cam's topic in Video Piloting (FPV/RPV)I would be glad to trade a board for a printed case. I have PLA in red, orange, green & yellow. If you don't want to trade, I am definitely interested in just the board. Have you taken a picture of this attached to the whole project?
There shouldn't be any issue with installing a BNC or UHF connector on the R/C Tx. For best matching/efficiency don't use a single wire to the connector; You need both signal and shield. After mounting the connector on the case, a short piece of 50 ohm coax would be used inside the Tx wired as follows: Shield soldered directly to the PCB's ground plane (near the RF signal pad). The coax's center conductor soldered to the RF signal pad. Google for plans on how to build a vertical polarized 6-meter antenna your outdoor installation. For example: http://fedler.com/radio/6m_vertical.htm Note: I haven't built the antenna example, it's just a random project found with google.