Antenna to increase range ?

[jonysan]

Hi
I've just fitted a 5.8ghz 600mw tx to my phantom, and this is transmitting to a Diversity Monitor with inbuilt receiver (the twin antenna unit). Think I have set the channels correctly at 5885 on both the tx and the rx , and getting a good picture up to maybe 150 yds, after that the screen gets horizontal bars that roll up through the screen, this effect is increased when the Phantom is heading back toward me, so I guess the GoPro and parts of the Phantom are masking the signal.
I was hoping for more range/distance from this set-up. not much but maybe 300 yards?
So next move ! buy some decent antenna,
Any suggestions please, I was thinking Circular Wireless Skew Planar, or similar. also do I need three new antenna, (one on Tx, two on Monitor receiver, our will one good antenna work on the Diversity Monitor and pick up the signal from the new Tx antenna, leaving the other rubber duck antenna to just sit there!)
or maybe I've made a mistake in setting up the Tx, Rx/Monitor, as distance/range seems very low ?

thanks

 

[TickTock]

Circular wireless sells some really nice 5.8GHz helical antenna which make a good compliment to an omnidirectional like a monopole or skew planar. It isn't so much the gain of the antenna that helps but the multi-path rejection. At 600mW you can easily go 5X the distance so your problem isn't signal strength, it is reflected paths interfering with each other. Increasing TX power won't help at all since then you will just have a stronger garbled signal. Similarly, getting a higher gain omni-directional won't help with MP either. My guess is the reason it is worse when returning is the antenna is being blocked by the Phantom - giving the reflected paths more relative power. Anyway, I purchased circular-wireless' helixal and it works great but you do need to keep it pointed toward the Phantom. At 200mW TX video feed, I easily get good video out past the range of my controller (~600m) using a helical, skew planar combo as long as I have line of sight.

 

[jonysan]

Thank you for that information, it seems like a good idea to try to position the antenna either out to the side of the phantom, or at less as low as possible to avoid the GoPro, etc.?
Thanks again.