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sergio00

RECTRACTIL ANTENNA 2.0 ( for HIGHT ALTITUDE FLIGHT

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Here my 2nd. Retractil Antenna

The reason of this device is put the Tx antenna horizontal when we fly over the 800 mts ( 2400 feets ) of altitude.

You know that the whip antenna radiate by side. When we fly very hight ( over the 800 mts, we become to lose video signal becouse of the whip antenna can´t radiate us ( if the position is vertical , of course ).

If we want coninue ascending, we must fly far to entry in the radiation zone.

Is dangeous fly hight and far beouse the winds are very diferents there.

Well, all this problem is finish with this device. We will be able to fly over the club and very high without any problem.

The solution is turn 90º the antenna with a micro servo. The lever is on the antenna so we dont need modify the airplane :) . We must use a free channel to connect the servo.

When we ascending and become to lose signal, we must activate the servo antenna to turn it 90º and it will irradiate direct to the ground. The vertical position change to horizontal.

Them, when we want descend, we desactivate the servo antenna and the antenna back to the vertical position. Just that, is very simple and easy.

We need program the servo movent ( in the rc radio ), before paste it to the antenna.

Is very easy. Whe dont need any airplane change.

We used a micro servo, 2 plastic flanges ( i dont know the word in english) and a peace of plastic. Time: 15 minutes

The paste was done with ciano and epoxi.

I show you the photos.

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tphot0036323ix9.jpg

Edited by sergio00

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my first impression about this was: this is crasy !

but after thinking this throu a bit, I now say briliant !

Good idea, this will infact inprove both fly low and away, and fly hight,

depending on servo position.

another way is to use bigger receiver antennas and diversity receiver systems,

but this is simple and cheap to do.

The servo must be able to work without jammed by the TX, so this must be tested,

I expect some servoes to get a bit crasy when used so close to TX antenna,

this depends a lot on tx power.

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I did not fly high since long time, but with my glow plane i was using a small 5dbi square patch antenna pointing to ground. Thie antenna have a wide beam coverage when the plane is close, i was able to take-off easily and circle above me with very good reception. At landing reception was sometime not very good due to the plane position and to great distance i taked sometime

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This weekend whe tested the retractil antenna.

Very good news.

A friend did a high altitude flight. He put my retractil antenna in his setup.

When he was at 800 mts altitude, the noise appears in the screen. So he activated the antenna and put it in horizontal position. The noise desapears and the image was clean.

He got 1550 mts with his Easystar ( a Spain record ), and the image was very clean. He was flying just over the club at 1550 mts!! He used GPS telemetry.

The servo works very well without any vibration

So,,,, its works 10 Pts.

Sergio

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TODAY we tested the Rectractil Antena 2.0 again

J.carlos was the pilot and the plane owner.

He got 2521 mts of altitude just over the field!!!!!

8271 feets!! Airplane, the same: EASYSTAR MULTIPLEX

The antena Retractil worked excelent,,

Wich is the electric altitude record?? I listen that was about 2500 but i cant remember exaclty..

ANiBODY KNOW WICH IS THE ELECTRIC FLIGHTS HEIGHT WORLD RECORD?

In the field there was 7 FPV!! We had 4 RX following the flights

A very good info:

We put a wireless temperature sensor in the plane and the info was:

In the field: 22º C

At 1000 Mts: 12ºC

At: 1500 mts: 4ºC

At: 2000 mts: 1ºC them we lose the temperature sensor conection

Very interersting to mantein the LIPOS protected from the cold.

Sergio

Edited by sergio00

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Segio, you probably want to get some fiberglass insulation like they put in house roofs and wrap your batteries in it. Those lipo's won't hold their charge too long at 1c!

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Mark, you're absolutely right! I recently lost a fully equipped plane because I did FPV at low temperatures and suddenly the motor stopped and 2 minutes after that the video screen just got black :blink: Usually when I fly at low temperatures I heat up the lipo's a little in those cases the Pizza Delivery Services use and it works great. But that time I didn't :unsure: , and also didn't have an osd to monitor the power status, so I had to pay an expensive lesson... :(

But those Pizza cases are great for that! :-) Last winter I had 40 minutes flight time at temperatures below 0°C with a 2200mAh on my Easystar.

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Congrats Sergio!

Any movies from 2.5km up? Should be a spectacular sight! Oh, and what transmitter and receiver did you use to control your plane? I'm told that regular 35MHz equipment has a maximum range of about 2km.

Cheers,

Sander.

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Any movies from 2.5km up? Should be a spectacular sight!

You see very far away, but everything looks small and flat with the wide angle and low camera resolution. Funny a couple of times or to try to beat your record, but a bit boring otherwise IMO.

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I'm told that regular 35MHz equipment has a maximum range of about 2km.

Cheers,

Sander.

4,5km with a standard Futaba 4EX is the record I think. He´s a friend of mine, and with another 35mhz tx (Graupner MC19???) I´ve flown his plane up to 3,5km. But that´s not usual, he lives in North of Spain and there must not be rf noise at all there, the record was with a 500mw tx and 3db dipoles on both sides, and I don´t know anyone who has achieved half his range with the same stock video setup. He´s really lucky ;)

The only thing was not stock was the rc rx antena, wich he had doubled in its length.

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Sergio, if you can change the antena position, have you tried to use a higher gain one?

What about using a gyro to keep the antena vertical when you´re far away and make a turn?

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