Parabolic reflectors... best $14. I’ve spent

[rodgerbwg]

Hi gang,
Picked up a pair of those gold colored parabolic reflectors a couple weeks ago from Amazon at the suggestion a fellow droner friend. Put them in my bag and didn’t use them.
Today, I flew out over water to shoot a subject one mile away. I have flown farther than this before with no signal loss. Nevertheless, I started to get two bars, no bars for a second, then four bars. In other words, erratic behavior. So, while the RC was pointing at the bird, I grabbed the parabolic reflectors and slipped them over the antennas.
Instantly, I had a solid four bars, which never waivered once throughout the remainder of my flight.
Just wanted to pass this along... they are worth the small outlay of cash that they cost. The only caveat is that they must be pointed towards the bird at all time, as they are very directional.
Hope this helps...

Not only very directional and narrow, they will fry the final output of your transmitter over time.

 

[wa5tef]

Zeldon 50: NO they will not! That reflector has nothing to do with the final amps unless it induces a reflected current back into them. I cannot see how a properly tuned ( correctly spaced from the element ) would cause that to happen. I have done much operations with parasitic reflectors and directors including dishes placed near the radiating antenna element with no problems noted. I'd be interested in where you heard this?
Anyway, thanks for posting. We need to get this cleared up quickly.
Jim
W5TEF

 

[rodgerbwg]

I work with this every day and what is happening is that the pattern is omnidirectional (in lobes) and the power is reflected back into the antenna and down into the final which is essentially a short. Think about what is happening. Your range is increasing in the direction of the reflected power out front of the reflector. The same thing id happening the rear of the antenna, on the back side. Put a Watt Meter in line and watch what happens when the Reflectors are installed. That will prove it. I see by your Call Sign that you are in the U.S. and the Rules state that the Quad must be in sight at all times. I hardly think that you can see a Phantom a mile away!

 

[wa5tef]

Yes, I agree but you will observe very few fliers follow this outdated regulation. Not saying it is ok but out in the rural area where I am I get a superior view, especially with Litchi than I do by looking at the drone.

And yes, i too have worked with many antenna designs and I stand by my first statement. The only signal that is reflected back to the transmit antenna is the one at 180 degrees and that reflected signal that goes back by the radiating antenna is thus in phase with the original wave. This feature is what adds to the gain overall. This reflected wave would influence the main antenna to some l degree but if the feed line circuit is designed properly then the signal would not get back to the finals. It sounds like you work in the commercial communications field. I am an amateur radio operator and for the past 55 years have been active in changing things to see what happens. I normally start out with proven ideas and work from there, trying to understand why something works or not. Then I am free to make changes and observe the results. Most of the time, I waste the effort but it sure is fun trying. In your field you probably done have that much time or freedom to experiment.

I'd love to understand where you get your information that the reflectors will damage the finals "after time". Please share that with me and the group. I am always open to new ideas or opinions on old ideas. Thank you again for posting.
Jim
WA5TEF