Modified parabolic antenna so they fit properly

Snowwolf · Dec 19, 2016

All the antenna parabolic enhancers all seem to be constructed wrong, the are made so you can't angle the antennas right back which is what you need to face the drone in flight, I re drilled the brackets so the shields sit further up on the antenna and you can angle it right back so it faces upright to point at the drone when in the air, I covered original holes with a bit of sticky aluminium foil.

lmayes69 · Dec 19, 2016

I think its more important to make sure they are parallel to each other. I do have to angle my antennae forward, but i just compensate for it by angling the controller ... Nice design though .

Snowwolf · Dec 19, 2016

I prefer the controller to sit naturally on the lanyard and have the antenna pointing up towards the drone, I was doing what you said and angling the controller up but found it would gradually end up the angle it wanted to sit at and then I found the antenna pointing downwards and getting the low signal warning, works perfect now and also the full antenna is sitting in the middle of the shield for better transmision, I am still mystified why them make them all wrong ?

wa5tef · Mar 28, 2017

How do you keep the distance from the stock antenna to the surface of the reflector the same all the length of the antenna? If one end is closer, the radiation pattern will be distorted and thus lose directivity and gain.
Jim
WA5TEF

JimmysWoodshop · Mar 28, 2017

This is the first thing I did when I got mine. Good thinking snowolf.

When I do distance flights I set the controller on a flat table and the Antennas should be tilted slightly back at an angle of 88.4 degrees at 15000 ft out (400ft high) to maximize signal. Yes I'm a nut. But it works.

So you have to widen the holes or shave the bottom of the boosters to get enough tilt back.

JimmysWoodshop · Mar 28, 2017

wa5tef said:
How do you keep the distance from the stock antenna to the surface of the reflector the same all the length of the antenna? If one end is closer, the radiation pattern will be distorted and thus lose directivity and gain.
Jim
WA5TEF

The good ones have a slot on the bottom and on the top so it keeps the same distance from the antenna...

wa5tef · Mar 29, 2017

Very interesting! From the photo of the insides of an antenna, there are two sets of folded dipoles, fed in phase so that they radiate equally well in all directions. This would have one "hot spot" about 2 inches from the top and another about two inches from the bottom. By being in phase, the two signals from each end of the antenna would add together to double the output, or 3 db. This same logic would increase the receive the same amount. The reflector then collects the signal from behind the antenna and focuses it toward the drone. I plan on doing some testing maybe tomorrow to determine the beam width both horizontal and vertical. I'll post here, my findings so maybe all of us can give some input on what we find. If anyone has already done any of this testing, please post it also.
Thanks,
Jim
WA5TEF

JimmysWoodshop · Mar 29, 2017

wa5tef said:
Very interesting! From the photo of the insides of an antenna, there are two sets of folded dipoles, fed in phase so that they radiate equally well in all directions. This would have one "hot spot" about 2 inches from the top and another about two inches from the bottom. By being in phase, the two signals from each end of the antenna would add together to double the output, or 3 db. This same logic would increase the receive the same amount. The reflector then collects the signal from behind the antenna and focuses it toward the drone. I plan on doing some testing maybe tomorrow to determine the beam width both horizontal and vertical. I'll post here, my findings so maybe all of us can give some input on what we find. If anyone has already done any of this testing, please post it also.
Thanks,
Jim
WA5TEF

Is there a way to determine the dispersion of the signal? Degrees left or right before significant drop off. Also if having the sticks tilted in towards each other will compress the signal together and increase range? I want to know everything about this setup. I've gotten to 18,000 ft stock antennas but I know there's room for more!

wa5tef · Mar 29, 2017

Wow, 18,000 feet is pretty good! No to tilting the antennas in any way. If they are designed to work together. They should be parallel as close as possible. I'll test the dispersion or beam width next time I fly. I can measure the signal at a particular angle and then plot a graph. I am also going to check the vertical dispersion. After I get the data I'll post it here or if you will email me your address I'll send directly to you. My email [email protected].
Thanks
Jim

JimmysWoodshop · Mar 29, 2017

wa5tef said:
Wow, 18,000 feet is pretty good! No to tilting the antennas in any way. If they are designed to work together. They should be parallel as close as possible. I'll test the dispersion or beam width next time I fly. I can measure the signal at a particular angle and then plot a graph. I am also going to check the vertical dispersion. After I get the data I'll post it here or if you will email me your address I'll send directly to you. My email [email protected].
Thanks
Jim

Thanks! Most people don't know to have your controller stationary on a solid surface, antennas up, flat side aiming directly at craft, in order to get maximum distance. People just hold the RC up in the air shaking and moving and then complain when the signal is lost. Just a degree or 2 out of line at a mile out and boom no signal. I use distant visual references (no smart modes) to precisely aim the antennas with the correct tilt to get 3 miles constantly without any signal loss. It's all in the details.