Review of KUUQA - Copper Parabolic Reflectors

[Fishie]

I have the same but in "silver" from a no-name supplier via Amazon UK. They work great but I have to remember to face the aircraft

One thing to note on mine is that the holes are difference sizes with no indication of top/bottom and I've been too forgetful to write on the yet. I have to remember to actually look at the holes once unfolded before mounting.

At least they are trivial to remove quickly once the aircraft is directly overhead on an RTH landing and you need to orient the antennas horizontally

Thanks for the comment. Yes I wrote about installing upside down and I needed an arrow or something lol. Glad you know how antennas work in their orientation to get the most out of them!


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[Peter Galbavy]

Thanks for the comment. Yes I wrote about installing upside down and I needed an arrow or something lol.

I must have missed that! Sorry! At least it's a general design/production issue then

 

[Fishie]

I must have missed that! Sorry! At least it's a general design/production issue then

I also talked about facing the drone. I should have mentioned however to avoid the reflectors with only one hole. Yes they may work but that second hole is there for a reason...to keep the distance to the foci the same for best efficiency. It's a crappy video but did you see it on the Amazon link? I took a laser and the laser ALWAYS was perfect at the center of the hole no matter where the laser was placed...provided it was aimed perpendicular to the reflectors. Amazing how a parabola works really!


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[Bobcat90]

How did you clean the Reflectors?


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[Fishie]

How did you clean the Reflectors?


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Copper is cleaned fairly easily with a mix of salt and vinegar! Salt is the abrasive and when combined with vinegar creates a mild acid. Hope that helps.


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[N017RW]

May not be an option here but no benefit to Copper. Aluminum requires no cleaning.

 

[Bobcat90]

Thanks, Fishie


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[wa5tef]

WetDog, thanks for the photo of the internal board of the antenna. It seems to be two folded dipole antennas first, fed exactly in phase and the second set above it, in the tip of the antenna are also fed in phase and by noting the length of the strip connecting the two sets of folded dipoles, both sets are in phase. Very good design! The radiation pattern of one of these complete antennas would be a figure 8 broadside to the length of the "stick". I would estimate the total gain to be about 6 dbi. Now if the second stock antenna was the same and also used for the same task, would boast the gain to 9 dbi. Maybe some electrical engineers can verify this. Also, I agree that the copper does not add anything except stronger physically. As long as the surface is smooth and parabolic the reflecting material won't matter much. Mylar for example would also work and be lighter but hard to get smooth. If the second antenna is for a different purpose, for example video transmission, then both would be probably the same design and size electrically. Does anyone know the purpose of each antenna? For example is one for control of the drone and the other for data or video? It sure would be nice to know.
Thanks,
Jim
WA5TEF

 

[N017RW]

You can find the antenna gain and other Part-15 type acceptance test specs/results on the FCC website with some searching.
Use the ID number(s) on the device(s). Sorry I don't have links handy at the moment.

IIRC, the gain is about 2.3 dBi.

73s.

 

[wa5tef]

This afternoon, I tried another test of the parabolic reflectors. I flew at 200 feet and kept the drone pointed in the same direction all the way. The first stop was at 1000 feet and being pointed directly at the Phantom 4, the signal strength was 100%. I then turned to the 90 degree position and the reading was 97% and 180 degrees it was 87%. Next stop was 1500 feet where I got 100%, 91% and 74%. Then at 2000 feet it was 100%, 89% and 74%. Next it was 2500 feet it read 100%, 86% and 48%. At 3000 feet it was 94%, 76% and 51%. At 3500 feet it was back to 100%, 71& and at 180 degrees it disconnected. I went on out to 4000 feet and got 92%, 69% and again disconnected. At 4500 feet it was 80%, 74% and disconnect. Then at 5000 feet it was back up to 96%, 58% and again disconnected at 180 degrees. I am not satisfied with these results. The trend should have been down all the way, not up and down at some spots. I may have had a house almost block the signal past 4000 feet so I will find a different location and repeat the test. With the drone sitting at 200 feet altitude and out 3000 feet, I tried a different test. I held everything stead except I slowly rotated (yaw) the drone counter clockwise a full 360 degrees but did not notice any difference in signal strength which is strange because the on board configuration of the drone's antennas should be anything but omni directional. I want to repeat this test at maybe 7000 feet and see if I notice a change at that distance.
The flight patch was about 100 feet away from a public road and there were no electrical or phone lines visible. It crossed two creeks that had dense underbrush and trees but I believe I was high enough for that to not be an interference. It will be a few days before I can test again due to the severe weather we have moving into our area tonight and tomorrow and I will be tied up in our local weather nets. As soon as that is over I'll proceed to test again.

Thanks,
Jim
WA5TEF

 

[Fishie]

Thanks for the great field test. Keep in mind that both antennas according to DJI are 2.4Ghz. 2.4 and then 5.8 (the higher you go) the signal does not propagate through or around solid objects like building or trees.

I am not sure how DjI gets video and transmitter signals on a 2.4 frequency band. Back "in my day" of building a good FPV system it was a no-no to have bithnon the same spectrum.

I suggest you try splitting the two parabolic into two separate pices and print the up as far as possible and in a slight "V" formation instead of parallel. Also just like a patch antenna...ALWAYS face the drone with the antennas perpendicular to the drone's location for the best results.

If you do this I'd love to hear your results! Lastly keep in mind....the further out, the better it is to be higher in altitude for the clearest reception.