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  3. Analog HD FPV Video. Why Not?

    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.
  4. Last week
  5. 50mhz TX antenna mod

    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
  6. 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?
  7. 50mhz TX antenna mod

    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.
  8. Earlier
  9. The meter is targeted for FPV hobby applications so it certainly supports the 23cm (1.2/1.3GHz) and 70cm (433mHz). But it omits the HF band (<30MHz) since FPV'ers don't use it. There's a chance you can cheat and use the 433MHz mode for HF power measurements. But I have no idea how accurate it would be since the cal data for 70cm/433MHz would be different compared to the HF band cal data. Maybe results would be good enough for you, or maybe not. The AD8318 sensor covers 1MHz to 8GHz. Adding a new frequency range not currently supported by the firmware would require Arduino coding. Hardware would remain the same.
  10. My objective is to do measurements on 70cm band, 23cm band and HF bands. Measurements regarding output power and, later on, VSWR. Do you think that for a rough estimate, it will be adequate building this DIY RF Power unit? Measurements don't need to be precise, it is just to have an order of magnitude of the output power and VSWR. I can try to modify the code at a later stage as I have already programmed in arduino...
  11. The existing code supports 60dB attenuators. For rough VSWR estimates the 433MHz setting should work OK (despite the extreme RF difference). But if you should ever need to make accurate absolute RF power measurements then you'll need to dig-in and modify the code for the HF band's dramatically lower frequencies.
  12. Hi Mr. RC-Cam, Many thanks for sharing this great project! I'm very interested in this project and wonder if I can use it for test output power of my HF rig (100W PEP output) - guess 60dB attn will be ok. Also can I use it for VSWR measurements on my current HF antennas for a rought estimative of VSWR in HF bands? thank you
  13. I recently picked up an old Airtronics Vision tx listed as not working, parts only, because it has a bnc connector on the top of the case where the stock antenna would have fit in, and I was interested in seeing how the bnc connector was installed. Turns out the tx does work - all the better. Inside the case it looks like whoever added the bnc connector just used a piece of hookup wire from the old antenna base mount up to the bnc connector at the top of the case. Seems this woud work ok if using an antenna with a bnc connector at the base. My need is for an external antenna about ten feet from the tx - the tx would be on my desk, and the antenna outside a window. Would it be better to use a piece of coax internal to the tx from the antenna connection up to the bnc at the top of the case? Only other post I've seen about using an external antenna suggested removing the transmit module, and locating it separate from the tx. In my case, the outside location would be more or less permanent, so not sure about the durability of the tx module with winter coming even if it is in a waterproof case. My goal is to get a reliable signal about one mile away. More or less line of site except for a lot of trees. Tx antenna will be outside a second floor window, and the rx antenna will be about 15 - 18 feet above ground. I will provide more info on the project if needed. Thanks, Mike
  14. Thanks for doing it. Maybe you'll find someone to trade a PCB for a printed case.
  15. I have redrawn the artwork so boards will fit, should have boards in about 10 days.
  16. I apologise for the DECADE old thread bump, but this is EXACTLY what I'm trying to achieve with my current project. I have a tiny HD camera with a narrow FOV pinhole lens. I'd like to replace it with a wide angle lens. I'm having trouble finding a HD camera that is small and light enough to mount to a micro drone, hence why I have to perform a lens swap on this camera. It weighs less than 4 grams once de cased. If anyone knows of a great micro HD camera I'd love to hear it Here's a video captured with my current HD micro drone with the narrow FOV.
  17. Any extra space in the area where it goes or does the board fill the whole space?
  18. If you look at the photo of my blank Perfboard you can determine the size. Each drilled hole is 0.1". So I estimate the irregularly shaped board is approx 1.4 x 1.5 inches.
  19. I've had a difficult time finding someone that would print your case for a reasonable price. I may resort to having a Chinese company print me a few. Can you measure your case and give me the size of the area where the buffer goes in the case? After I submitted the artwork I did an exploded view of your circuit board and realized that your board appears to be about 1.6X1.6 inch, I should have done this before I submitted the artwork I know. These boards are cheap to have made though, I can easily get the size down to 1.6X1.6
  20. Does it fit inside the 3D printed case I published? If not, how does it mount on the HeadPlays? Pictures would be great.
  21. I should also mention that to populate this circuit board requires a very high level of soldering skills.
  22. I don't know if anyone would be interested but I have had 10 circuit boards made of MR RC cams buffer circuit for the headplays. Three of the boards are spoken for leaving seven that I would sell for $4 + shipping. I can provide a BOM (parts list) with Mouser p/n's so that there is no need to look up part numbers, this also insures that the proper physical size of parts. I have not tested the board yet because I'm still waiting on my diversity receiver from Banggood which is due in next week so I would like to wait until it is tested before I ship any out. The board measures 2"X2" Thanks, Mark
  23. Oh ok, this is pretty cheap so yeah i will try that when i have some time Thanks a lot !
  24. You can't detect a video level compatibility issue (a common problem) by simply viewing your camera's image on a monitor. You need a o-scope or this tool to do it. Even if you cannot repair the problem yourself, you will have identified a purchase that is not 100% compatible (which is valuable knowledge).
  25. Yeah sure i already looked at this but i think i will not be able to know what to do to have a better signal even with this material :-/ I dont have material to change cms components, just a TS100 with the smallest tip
  26. You are welcome. I hope they can help you. If you are serious about finding the best matching vTx / vRx pair then I recommend you build this tool to test your purchases: https://www.rc-cam.com/forum/index.php?/topic/4126-diy-fpv-video-calibration-tool-low-cost/
  27. Oh ok, i hope they will be able to make it work for me then They know which VRX i'm using.. I want the best signal but there is not a lot of VTX with smartaudio for nano quads Thanks again Mr RC-Cam you are definitely the best to talk about this subject !
  28. As I have mentioned in my various discussions in the past, there's several RF & Video related specifications that must be maintained in order to ensure a reliable FPV system. Video emphasis is just one of many important characteristics. For example, your exact problem might not be video pre-emphasis related. It could be incorrect video level, RF carrier error, or something else. And even if all the important specifications are understood by the original designer, the end product sometimes works poorly. Performance issues can be due to economy priced components (tolerance issues) and inadequate quality control. But I agree, a well thought out FPV video system standard that is observed by everyone would be great. Unfortunately, this holy grail idea is not likely to happen in China because of their manufacturing culture. And as many experienced engineers say with a smirk: The thing about standards is that there are so many of them to choose from.
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