Very cool video. Flying down a mountain like that is something our multirotors and helicopters just can't do as well.
Update on this from the comment section of the YouTube video, Great video? What antennas did you use on the ground and what frequency video are you using? Also do u use diversity or antenna tracker? Thanks rcfanatic123 1 week ago 2.4GHz RC link with 7dbi patch on the transmitter and 5,8GHz video link with diversity (7,5 turn helical + spw antenna). Works pretty good. BKMorpheus in reply to rcfanatic123 1 week ago
I think the 5.8 Ghz video systems are better than some of the rumors. I think the Roswell Flight Test Crew also use 5.8 Ghz. Plus the 5.8 Ghz antennas are quite small. Like these: http://www.hobbyking.com/hobbyking/store/__27750__5_8GHz_Circular_Polarized_spiroNet_Antenna.html
I was referring to the 2.4 Ghz RC transmitter with a patch antenna for long range use. I always thought it would work, this proves it.
Yes, they probably did the standard SMA connector hack in place of the stock antenna, then screwed on a 2.4G patch antenna and went flying, with a short coax (under 4 feet) you would get a lot of boost, just need to keep the antenna pointed at the plane with either a tracker, or just some guy holding the antenna, I suppose you could just mount the patch on the back of the transmitter, and then point it yourself.
Yes, about 6 foot is the max you can do on small diameter coax, with a longer cable your 100 Mw in becomes 50 Mw out at some point and there is a diminishing return. The cell phone towers use huge hardline coax, sometimes filled with dry nitrogen under pressure to keep the humidity out.
So Trevor's system gets around this because he plugs into the trainer port right? But his transmitter box was not located on the tripod with the antenna tracker but on the table so he must have a coaxial cable longer than six feet.
He has no coax, just the rubber duck antenna right off the UHF box that is sitting on the table, the only cable is the trainer port PPM cable from the Tx to, well, the Tx He has no RC control antenna on the tripod, just video Rx, but being UHF which as compared to 2.4 Ghz, it is really low frequency. UHF is affected much less by coax loss. With something like LMR-400 coax and good connectors you could put up a 100' run of the stuff and the UHF will shine right through it with no issues. Plus it puts out like twice the power to begin with, UHF=250Mw VS. 100Mw on 2.4
DOH! That's right, I remember now that the antenna was on that black box leaning against his toolbox so yeah, no coax at all. Am I supposing correctly that he could eventually mount that black box on his antenna tracker if he wanted even though the antenna he is/was using isn't directional, or would if affect his video receiver?
No need on the tracker, just put it wherever, a mag mount on the roof of a car would be the best, or at least just up on a pole over your head. If you needed to fly your RC more than 50-100 miles away then you could add a Yagi to the antenna tracker
