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Corey

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About Corey

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  1. Regarding what a diversity receiver does... You need to have at least TWO receivers and two antennas if you use diversity, but you use just one tx on the aircraft. The diversity unit takes the two input signals, decides which one is best, and then outputs only the strongest signal to whatever you are using to view or record the video. I think it does it something like 500 times a second so it's visually seamless. I've read that it can make a real difference in the clarity of the reception, even if the two antennas are less than a foot apart, and in MY EXPERIENCE it does improve things significantly. Both the Yellowjacket and the Oracle units come with pretty good instructions and the hook-up is very straightforward. Corey
  2. Hi Matt - Enjoyed the video! There's a lot of experts in here who can give you far more detailed advice than I can, but for what it's worth I'll give you my feedback after having spent some significant "trial and error" dollars over the past year on FPV flying and equipment. The 5.8ghz stuff is newer and more expensive, which made me think it must be better. I currently have two Yellowjacket Pro diversity receivers that cost close to $600 each, plus three of the matching Stinger transmitters at around $250 each. After playing with them for several months I've gone back to 900mhz equipment because it works better FOR ME. I fly in fairly populated areas and I get better reception with 900mhz stuff. All of it is on channel 1 (910mhz) because that's the only legal 900 band in the USA. One drawback to the 900mhz is that the patch antennas are double the size of the 5.8mhz antennas, but that's not really all that big a deal FOR ME. My goal has been to get a clean signal for up to a mile flying at about 400 feet altitude. I'm not opposed to paying for excellent equipment, as long as it's worth it and does the job as advertised. I've experimented with FunJets, EasyStars, Twinjets, and also a Trex 500 heli. I've been told that a 250mw tx is all that should be needed for a good signal up to about a half mile, but I've found that 500mw rx's work better FOR ME. The 1000mw works well too, but it gets a bit warm and drains the battery faster. Diversity receivers are a GOOD thing, whether built-in like on the YellowJackets, or as in a separate piece of equipment like the Oracle units. In MY OPINION the Oracles are a good value for the dollar. Bottom line, I still haven't got a system that I'm totally happy with, or even very close for that matter, but I have learned a few things! If you find the perfect combination be sure and let me know! I'm still trying to find the time to play with two tx on the same aircraft, each on a different frequency to see what I can learn from that. I'd record them individually at first and they run them to a diversity receiver to see if getting the best of both worlds made a significant difference. Corey
  3. Thanks for the information guys! My bad Kilrah, turns out the receivers are actually each running on their own single-cell li-ion battery. I'm going to replace them with receivers that don't have a battery and require a 12V input. I'm now thinking maybe an 8000mah 3-cell lipo with 7 separate connectors going out to the various devices might be good. Regarding how the set-up is working with 3 Oracles, this video I posted on YouTube was done with the same set-up, except on this one I was using two Yagi antennas and two Patch antennas with the 3 Oracles. Corey
  4. I'm currently using four 900mhz video receivers and four patch antennas on one of my FPV set-ups. The receivers are connected to two Oracle diversity receivers and each Oracle receiver sends its output to a third Oracle receiver. That's seven separate power requirements. The four receivers each have their own small 2 cell lipo battery and I have been using a 3 cell 2200mah lipo with a single home-made connector that feeds all three diversity receivers with power. It seems to work pretty well but I've been thinking I'd rather use a single 12 power supply off a generator or something so I don't have to worry about which battery is still good and which is running down. Is a portable generator with a 110V multi-outlet strip and all the various adapters plugged into it a good solution, or is there something that might work better? Also, I want to use a 3 cell 2200mah lipo to power a 12V video tx and 12V camera on one of my planes because I could use the weight for proper CG. Will using a battery with that much capacity cause any problems when they only recommend 500mah for each piece of equipment?
  5. This is just sort of a curiosity question that came to mind today... I was wondering if you could use two cameras spaced apart (like your eyes) on your aircraft and then feed the signals separately to the left and right screens of your video goggles. Assuming that it could be wired up if you knew what you were doing, would give more of a 3D view of the flight or would it just be a mess?
  6. I had the same problem with the Blackstork GPS when I first installed it on an Easystar a couple months ago. The manual said something about this happening and suggested playing with the wiring to correct the problem. After randomly re-routing all my wiring and double-checking all the connections it worked. Not sure what the specific problem was but at least I was able to get it working. For what it's worth I have the GPS wire lead as isolated as possible from all my other wiring. I'm really new at this so keep in mind that my comments and advice might not be worth all that much!
  7. Thanks for the info. Regarding the patch antenna orientation and to make sure I understand correctly, if I overlap the beam coverage it should reduce mutlipath interference but reduce the overall coverage area? Also, would it be worth trying to significantly separate the patch antennas from each other or is that not an issue? I was thinking about putting one of the Yellowjacket receivers with its two patch antennas a couple hundred feet or more away from the base set-up and then bringing the output signal back to the base station Oracle receiver via a separate Tx and Rx on a different frequency. Any thoughts?
  8. I've got some new equipment to try out this weekend and was hoping to get some info to make sure that I'm at least thinking in the the right direction as far as set up is concerned. The equipment is on the 5.8 frequency. I have two Yellowjacket pro diversity receivers feeding into one Oracle diversity receiver. My Trex 500 heli has a 250mw Stinger Tx with the stock whip antenna pointing straight down, several inches away from the radio Rx and the speed controller near where the tail servo is. Then I've got four 8dBi patch antennas for the Yellowjacket receivers with specs of 75 degree horizontal beam and 60 degree vertical beam. For the "theoretically ideal" antenna placement to get maximum coverage would I be putting each antenna at a 75 degree angle to the adjacent antenna? Then I'm thinking that each antenna should be angled upwards at least 30 degrees so that the bottom of the beam is parallel to the ground, or higher. Is that the right way to approach this? I don't anticipate needing a 360 degree coverage area for this project. I just want a clean video for the entire area in front and to both sides of where I'm standing for a half to three quarters of a mile and at vertically for probably a quarter mile or a bit more. I also have four 11dBi patch antennas with narrower beams, and also two large 19dBi omni "pole" antennas that I bought before joining this forum and finding out that I probably got the wrong thing. Should I consider trying them for anything with this type of a set-up? I've also read some seemingly conflicting info on whether or not patch antennas should be placed close to the ground or higher up. Is there a right or wrong way? This particular project is really more for my neighbors than for me. I'm not flying FPV for this, but rather feeding the video output to a couple pairs of FatsShark video goggles for my neighbors and thier kids to pass around while I fly in the park next to my house. It keeps them happy and then they don't bother me when I fly other rc models there! Thanks in advance for any comments or suggestions.
  9. Aha! Buffer / Amplifier... Where can I read about and find one of those?
  10. In my continuing hobby-level experiments I tried something today with crummy results that seemed kind of odd and I can't figure out what was going on. I used both a 500mw 900Ghz TX and a 250mw 5.8Ghz TX on the same heli, mounted about 4" apart, both with the stock whip antennas facing straight down to the ground. My thinking was that if one frequency was not getting decent reception for whatever reason the other frequency might work fine. The wiring from the camera up front was spliced to feed both TX units and I ran all three devices from one 3 cell lipo, separate from the lipo for the heli's power. The two ground receivers were connected to an Oracle diversity unit and the resulting output was a fast flicker from with the image from one frequency shifted slightly out of registern with the other. The 900Ghz receiver was pretty standard with an 8dBi patch antenna and the 5.8 receiver was a Yellowjacket Diversity receiver with two 8dBi patch antennas. When I manually switched the output from one receiver to the other the image was indeed shifted. I'm no rocket scientist but it seemed very odd to me since both receivers were using the identical video signal (weren't they?). Needless to say, the heli never left the ground and I guess I won't be trying this again. Any comments? Would it possibly have worked with both TX on the same frequency? Also, while I'm here... Has anyone used the DMD long range fpv equipment with better than usual results and is there any where you can get English documentation for their product? Corey
  11. Sorry, me again... This is what happens when you get good information, more questions! Can I use an RF signal amplifier on the receiver side rather than aircraft side? I was looking at a 5.8 signal amplifier that boosts the signal to 1W but it's a pretty hefty unit and wouldn't work on the aircraft. I thought I'd read some info about this but can't seem to find it. Can I put it between the ground antenna and the receiver?
  12. Man, you guys are smart! I've learned more on here in 24 hours than I did in 6 months of Google searches and shelling out cash to try what I mistakenly thought was going to fix the problem. I should split the $7K between you guys! I had no idea about the problems with the omni antenna but it certainly makes sense now that it's properly explained. Terry, that video of yours is great! How do you set up 4 of the patch antennas to work like that? Are you using multiple diversity receivers in a sort of chain? Also what is the physical configuration of the antennas, and do you have them on the ground or up on a stand of some type? Is the 5.8 frequency part of the reason it looks so good or is it more in the antennas? Lots of questions! Thanks everyone for the great ideas and information!
  13. This video is typical of what I've experienced with most of my wireless exploits... This one uses a 500mw 900mhz tx with the stock whip antenna on the tx facing straight up from the EasyStar canopy. On the ground I am using an 8dBi HG908U-PRO Hyperlink fiberglass pole omni-directional antenna attached to a tripod stand that puts it about 12 feet off the ground. I don't think the aircraft is ever more than about 2000 feet from me in this video but it still has a lot of static and drop outs. Maybe I'm just expecting too much? http://www.youtube.com/watch?v=Nv7jHHB7kxY
  14. After disappointing results using wireless equipment from several of the RC wireless websites I've been looking at getting some "higher end" equipment that is claimed to be of the quality required for military and law enforcement use. What I'm wondering is if anyone has gone this route and found that the relatively expensive equipment is really worth the money. Several of the companies I sent inquiries to have told me they have what I want and that those other companies I've bought from are using cheap Asian import stuff that isn't really what it's claimed to be, but I'm skeptical and somewhat new to this whole thing so any advice or experience of others is appreciated! My inquiry to the various companies asked for an air to ground system that would result in noise and static free video for a distance of at least 1 mile, and not required to be LOS. The system I am most intrigued with is from dyplex.com and uses a 2W video tx on the 1800 mhz frequency with one of their standard receivers. The cost of the equipment with basic antennas and cables is about $7000 but they say it is worth the money and will do what I want it to do and more, most likely up to a distance of at least 3 miles. Anyone know if this type of equipment is really that much better than other stuff you can find on the internet claiming to have the same specs at 1/10th the price? Maybe I'm just not using my antennas right on with all the stuff I've tried so far, which has already cost me several thousand dollars with no real success. I've got 900, 2.4, and 5.8 stuff up the ying yang with all sorts of fancy tripods, antennas, and diversity receivers and still every flight and/or video that I do has random static and drop outs from as little as 100 feet away... Keep your responses simple because as I said, I'm still pretty new at this!
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