7-Element Yagi Range Extender 2.4 Ghz for MM (CE)

[Quadbee]

Hey Guys,

I´ve developed two new Range Extender 7-Element Yagi versions for the Mavic Mini (CE) on 2.4 Ghz. They are computer optimized with 4NEC2 an antenna modeling software. It took me quite long to reverse engineer the rf-parameters of the original dipols of the remote, because they use dual band antennas with shortend dipols and capacitors at the end. The standard Range Extender Design for 2.4 Ghz with the 5-Element version which goes around the last months is not bad but hasn´t the best SWR ratio, so I decided to do better

The standard 7-Element version has about 12.4 dBi gain with a length of approx 15 cm and the long version 13.4 dBi with a length of 20 cm. I´ve done some measurements with the RF Power Meter V2 from ImmersionRC and the values seem to be realistic. Attached you find photos of the antennas and the radiation characteristics. My first tests were very promising but I´m living in a very dense populated area in Germany and I have to find a good place at first where I really could fly out the limits.

Cheers

 

[RadioFlyerMan]

Hey Guys,

I´ve developed two new Range Extender 7-Element Yagi versions for the Mavic Mini (CE) on 2.4 Ghz. They are computer optimized with 4NEC2 an antenna modeling software. It took me quite long to reverse engineer the rf-parameters of the original dipols of the remote, because they use dual band antennas with shortend dipols and capacitors at the end. The standard Range Extender Design for 2.4 Ghz with the 5-Element version which goes around the last months is not bad but hasn´t the best SWR ratio, so I decided to do better

The standard 7-Element version has about 12.4 dBi gain with a length of approx 15 cm and the long version 13.4 dBi with a length of 20 cm. I´ve done some measurements with the RF Power Meter V2 from ImmersionRC and the values seem to be realistic. Attached you find photos of the antennas and the radiation characteristics. My first tests were very promising but I´m living in a very dense populated area in Germany and I have to find a good place at first where I really could fly out the limits.

Cheers!

Brilliant! I need to try these on my amped system...

 

[Woodsman]

Too bad it won’t work with the Mini, it’s 5GHz.

 

[dirkclod]

Hey Guys,

I´ve developed two new Range Extender 7-Element Yagi versions for the Mavic Mini (CE) on 2.4 Ghz. They are computer optimized with 4NEC2 an antenna modeling software. It took me quite long to reverse engineer the rf-parameters of the original dipols of the remote, because they use dual band antennas with shortend dipols and capacitors at the end. The standard Range Extender Design for 2.4 Ghz with the 5-Element version which goes around the last months is not bad but hasn´t the best SWR ratio, so I decided to do better

The standard 7-Element version has about 12.4 dBi gain with a length of approx 15 cm and the long version 13.4 dBi with a length of 20 cm. I´ve done some measurements with the RF Power Meter V2 from ImmersionRC and the values seem to be realistic. Attached you find photos of the antennas and the radiation characteristics. My first tests were very promising but I´m living in a very dense populated area in Germany and I have to find a good place at first where I really could fly out the limits.

Cheers!

Seen one the other day and the guys looking to be a vender to sell
them here except The pins are copper. Just for CE though.

 

[Quadbee]

Just finished the 9-Element version with 14.3 dBi and 27,5 cm. I guess my next problem will be the battery

 

[scro]

Too bad it won’t work with the Mini, it’s 5GHz.

As per the original post, these were designed for the CE version of the mini, which has both 2.4ghz and 5.8ghz.

 

[PanX]

Hey Guys,

I´ve developed two new Range Extender 7-Element Yagi versions for the Mavic Mini (CE) on 2.4 Ghz. They are computer optimized with 4NEC2 an antenna modeling software. It took me quite long to reverse engineer the rf-parameters of the original dipols of the remote, because they use dual band antennas with shortend dipols and capacitors at the end. The standard Range Extender Design for 2.4 Ghz with the 5-Element version which goes around the last months is not bad but hasn´t the best SWR ratio, so I decided to do better

The standard 7-Element version has about 12.4 dBi gain with a length of approx 15 cm and the long version 13.4 dBi with a length of 20 cm. I´ve done some measurements with the RF Power Meter V2 from ImmersionRC and the values seem to be realistic. Attached you find photos of the antennas and the radiation characteristics. My first tests were very promising but I´m living in a very dense populated area in Germany and I have to find a good place at first where I really could fly out the limits.

Cheers

will you share any info about spacing and elements length ?

 

[Quadbee]

will you share any info about spacing and elements length ?

Right now it´s to early yet for sharing because I´m in the testing phase and unclear about how to go on with this project.

Yesterday I´ve done my first promising testflight with the antennas and as I guessed before the limiting factor was the battery

 

[PanX]

i think there is space for improvements:

 

[Quadbee]

A parabolic reflector in this size is almost useless and brings in best case 3 dBi as you can calculate here.

The 5 Element Yagi has about 10 dbi what brings 6 times more power than a dipol with 2.1 dBi. (db calc)

My 7 Element Yagi has 13.4 dBi what brings 14 times more power than a dipol.
My 9 Element Yagi has 14.3 dBi what brings 27 times more power tha a dipol.

Buts thats all just theory and needs to be flown out

 

[Carlos Costa]

9 elements?!? Won't that be a bit "too directional"? I think I saw somewhere that the more elements, the sharper you have to be to point it at the drone, right?

 

[Quadbee]

The beam angle of the 9-Element Yagi is a little less than 40°. So as an example when you are 3 km away the window in which your mini should be is about 2 km wide, what should not be too hard to hit. But when you wanna reach the maximum range of about 6-7 km you have to aim very precisely. You can see this in the diagrams at the beginning of this thread.

 

[Carlos Costa]

The beam angle of the 9-Element Yagi is a little less than 40°. So as an example when you are 3 km away the window in which your mini should be is about 2 km wide, what should not be too hard to hit. But when you wanna reach the maximum range of about 6-7 km you have to aim very precisely. You can see this in the diagrams at the beginning of this thread.

That's precisely my point. For a lesser distance the 5 or even the 7 elements should be enough, if not better. At the further distance, the wider the signal, the best to avoid missing the drone.
Don't get me wrong, I don't know much about this and may be completely missing the point, but I still think that your original idea of a 7 element would be the most balanced option. Of course, only a good field test may prove I'm wrong... or wright!
When will you do yours and can you take a smaller yagi for the sake of the experiment? Theories are only right to a point, but field tests are much more conclusive...

 

[TheFunker]

Hey Guys,

I´ve developed two new Range Extender 7-Element Yagi versions for the Mavic Mini (CE) on 2.4 Ghz. They are computer optimized with 4NEC2 an antenna modeling software. It took me quite long to reverse engineer the rf-parameters of the original dipols of the remote, because they use dual band antennas with shortend dipols and capacitors at the end. The standard Range Extender Design for 2.4 Ghz with the 5-Element version which goes around the last months is not bad but hasn´t the best SWR ratio, so I decided to do better

The standard 7-Element version has about 12.4 dBi gain with a length of approx 15 cm and the long version 13.4 dBi with a length of 20 cm. I´ve done some measurements with the RF Power Meter V2 from ImmersionRC and the values seem to be realistic. Attached you find photos of the antennas and the radiation characteristics. My first tests were very promising but I´m living in a very dense populated area in Germany and I have to find a good place at first where I really could fly out the limits.

Cheers

Great job man! ?
How would they perform with the CE version but with the RC in boost mode?
✌✌

 

[Quadbee]

Good question. But I think no big difference except the higher transmission power in boost mode could somehow be activated on the drone as well. Just increasing the power on the remote will not bring any big change. The advantage of the yagi-antennas is that they amplify the transmission and the reception at the same time.

 

[TheFunker]

Good question. But I think no big difference except the higher transmission power in boost mode could somehow be activated on the drone as well. Just increasing the power on the remote will not bring any big change. The advantage of the yagi-antennas is that they amplify the transmission and the reception at the same time.

Activating boost mode in the RC is the hack to make to get the higher range of the FCC model vs the CE model, no fake GPS BS, check it out here:

? That's where my question comes from! Let me know after you check the video please!

 

[Quadbee]

I´ve tested it a couple of weeks ago and it doesn´t change anything on the transmit power of the drone (CE). Believe me, I checked with a rf-meter and it only changes the power a small amount on the remote. Its not worth the effort

 

[TheFunker]

I´ve tested it a couple of weeks ago and it doesn´t change anything on the transmit power of the drone (CE). Believe me, I checked with a rf-meter and it only changes the power a small amount on the remote. Its not worth the effort

Perfect! Thanks alot for the info mate!

 

[Carlos Costa]

I've been testing a variation of the yagi. The X-Yagis, made by Miniformer. They are basically bigger recalculated yagis with some reflectors in the back.

There is a 5 element version (12cm)

and a bigger 7 elements (20cm)
.
Surprisingly enough, the smaller one was more effective than the bigger one.

It could be a misscalculation, but I'm figuring there is more to it... This is an early conclusion, as I only tested them twice (and I'm not really an expert), but I'm convinced that in this case the more isn't always the better...

The smaller x-yagi, on the other hand was very effective and easily surpassed the traditional 5 element yagi...

As soon as I have the time (and the weather allows me to) I'll give it another try and post my conclusions, but I think the small transmission power the CE mini has will limit the bigger yagis performance...

 

[Quadbee]

There is enough transmission power to feed any antenna. It all depends on the correct dimensions.

Here are the parameters for my 7-Element standard version (2.4G) build with 3 mm alu rods.

Distances from the middle of the original antenna:
R=-24 mm
D1=10 mm
D2=32 mm
D3=58 mm
D4=89 mm
D5=123 mm

Lenghts of the elements:
R: 57.93 mm
D1: 51.46 mm
D2: 48.99 mm
D3: 48.26 mm
D4: 48.76 mm
D5: 49.43 mm

Happy Longranging