|
|
|
|
|
|
||
|
Temple, GA, USA
Joined Jun 2009
2,343 Posts
|
Quote:
Near trees is fine, on the other side of trees is a no-no. You will probably be OK for one tree, but at some point a small forest will block the video signal completely. The same goes for 2.4g RC equipment, but NOT for 72mhz RC equipment. You can fly behind trees all day long with 72mhz. Many AP people use two cameras that are aligned to frame the same image, of course zoom or pan and tilt are obstacles. On a similar note, there is a Swiss company senseFly that does automated aerial mapping. Watch the video. Maybe they have a heli version. It ain't cheap though. Here is a similar video by Pix4UAV showing off their mapping software with images from a senseFly. Here is a senseFly running optiPilot which uses vision for autonomous collision avoidance. Sorry, I just had to show you these links. ![]() Cliff |
|
|
||
|
|
|
|
United States, TX, Carrollton
Joined Jul 2005
230 Posts
|
Cliff
The screen on the camera blanks for almost three seconds, but the video out never does. I can see no change in the display when taking pictures. The system I am trying to build looks more like this one, but not as exspensive or high tech. http://www.engadget.com/2011/06/03/m...inds-peace-wi/ |
|
|
|
|
||
|
|
Quote:
-Alex |
|
|
Latest blog entry: Project Covert Ops: Long range ground...
|
||
|
|
|
|
Joined Jan 2009
104 Posts
|
I got a very dumb question.
Bought a Yagi antenna on 2.4 to get the video signal, and need to install it on the antenna tracker. I was wondering, if the TX antenna is (as usual) mounted vertically on the plane, I should install the Yagi the same way, and not, so to speak, parallel to the ground, because the tx antenna will be transmitting vertically polarised, and the receiving antenna would be horizontally polarised if it's "flat" or as I tried to describe, parallel to the ground... Right? |
|
|
|
|
|
|
|
DX6i Antenna Question - Alex and Cliff - can you weigh in?
Hello - this is my first post here in this forum - and I've read all pages here and in the surrounding FPV antenna build threads. WOW. This has really opened up a new arena in RC for me to think about- I want to do it! Alex, I'm really grateful and amazed by your antenna refinements and new breakthroughs. And Alex and Cliff - for the extent of your sharing in an understandable way.
So, I hope this isn't a "don't ask that question", question. But I love the advice about starting off simply enough - and I live in the city and would like to get a solid mile of FPV without driving too many miles outside of town - and feel solid about it. And, being a minimalist at the moment, would like to keep to one radio - my dx6i. I don't know if anyone has really explored DIY development of this as compared to your recent breakthroughs: Here's my $64,000 question - isn't there a creative solution to having a better range for my dx6i - by removing the stock antenna and putting on a carefully matched Diy Omni or otherwise - I mean a break-through DIY matching antenna?. [I dropped my radio and broke my antenna a year ago or so, and it was just a wire inside the cheap plastic antenna casing. Yes, a very carefully measured out length and type of wire I understand, but still...(I read up in the forums and easily replaced it with an E-flite part)] If it was workable, for example, I'd love to stick a carefully matched cloverleaf (or otherwise) on my RC Tx. From reading and musing - I get that on the RC radio side it can't have overhead dropouts - so CP antennas may be out of the question. I also see that, even if I extended my range with a better antenna - if it existed or could be thought up - that the Spektrum TX/RX systems still would not warn me when out of range - like the 72mhz radios you frontiersmen have been using. I may be a month or too out from buying anything (budgetary reasons etc). And I've had great non-FPV experiences with this radio for all around park flying. Just wondering if anything solid could be done on the DIY side- I think a lot of us would be aided that are, for now, closer-in flyers, etc. Thanks in advance, Greg |
|
|
|
|
|
|
|
Greg,
Just my two cents (only because I am no-where near as knowledgable as many on this thread), keep an eye out on the classifieds for a solid 72 radio/receiver. 72 is older technology, but very solid and proven. You can find them for likely less that what it'd cost to put together an Omni antenna. **HOWEVER** flying in town with a 72, you take the risk of interference on the channel (crystal based) that you happen to be flying on. This would be an unknown if you aren't flying at an ama field. |
|
|
|
|
||
|
Temple, GA, USA
Joined Jun 2009
2,343 Posts
|
Quote:
- lower frequencies travel a little farther - lower frequencies penetrate trees a little better - the harmonics (1.8 and 2.7) are farther away from 2.4g The antenna is larger for 900 though. For some things that is important: - CP antennas - fast airplanes - small airplanes 900 is close to cell phone frequencies in some areas. There just is not that much difference between 900 and 1300. There may be more difference in two batches of 900's than there are between 900 and 1300. Please try to determine what frequencies are legal for use in your country before buying equipment. You don't want to cause problems, even if you don't get caught when you could just buy something on the right frequency to begin with. You might move to a more densely populated area. Cliff |
|
|
|
||
|
Temple, GA, USA
Joined Jun 2009
2,343 Posts
|
Quote:
Google is your friend. "yagi polarization"Cliff |
|
|
||
|
|
||
|
Temple, GA, USA
Joined Jun 2009
2,343 Posts
|
Quote:
There is a "dropout overhead" (called a null) on any antenna type for the same reason that a hairy 8 ball must have at least one cowlick. I have honestly wondered why there is not more talk of CP's on 2.4g RC for FPV. Probably because you would need a coax from the receiver to where you mounted the antenna (a short coax is best) and most of the more expensive RC rx's have two antennas... You need a CP on the tx too. Someone correct me if I am wrong, but I recall that the DX6i is a "park flyer" which would make it suited only to close in FPV flight. FPV begs you to fly it farther out. ![]() Cliff |
|
|
||
|
|
||
|
|
Quote:
Greg |
|
|
|
||
|
|
Quote:
The Dx6i may be enough to get me started - really in-close - until I find/budget a better radio solution dedicated to FPV amongst the ones you've laid out in the thread. Still pondering and laughing, Greg |
|
|
||
|
| Thread Tools | |
Similar Threads
|
||||
| Thread | Thread Starter | Forum | Replies | Last Post |
| Discussion How to calculate flight time - guide | ikorman | Multirotor Talk | 11 | Dec 30, 2011 07:22 PM |
| Discussion How many FPV pilots in the world? | rbmaze | Video Piloting (FPV/RPV) | 10 | Aug 03, 2011 06:16 AM |
| Poll Would you be interested in buying Ready to Fly FPV airplanes from a new FPV store? | FPVNOW | Video Piloting (FPV/RPV) | 36 | Oct 06, 2010 08:56 PM |
| Discussion Can this cam be used for FPV ? | SpookiePower | Video Piloting (FPV/RPV) | 8 | Sep 12, 2010 07:12 AM |
| Cool How cool would this be for FPV | Kai_Shiden | Video Piloting (FPV/RPV) | 2 | May 11, 2009 07:41 PM |