Interferences on Observer EB

[Helirono]

Hello,

Sometime I've big interferences problems on my Observer EB whichmakes mistakes on radio camera mount, video transmission and to the heli radio control !
Video transmitt : 2,4gHz
Camera mount radio : futaba pcm 1024, 72mHz
heli control radio : futaba pcm 1024, 41mHz

To my mind, the problem com from the hight voltage of the zenoah. (the plug has a interference eliminator)

Have you got a suggestion ?

Thank for your answer,
Renaud SILVESTRI

[cbergen]

Are you using a base loaded antenna, or is your antenna running along the landing gear?

Do you have pics of your bird?

[Helirono]

I don't know what you call a base loaded antenna, but indeed those 2 Rx antenna running along the landing gear.

I've included som pictures that I've just make.
As you can see, actualy the Observer is out of services. We had a little crash due to one on tha interference problem on the Rx heli control. :'-(

Also, you can see that I've protected the high voltage reel, with a magnetic metal connected on the mass, due to the fact that at first test, the video transmission was completly broke.

Please give me your suggestions.
Thank you very much,
Renaud SILVESTRI

[cbergen]

Lets start off with the obvious. A base loaded antenna or "whip" antenna is used to shorten the physical antenna length without much reduction in range.

It looks like this, http://www.ronlund.com/Merchant2/merchant.mv?Screen=PROD&Store_Code=heli&Product_Code=RVO1010 .

You have to be sure to get a frequency specific, ie one for 72 Mhz, one for 35 Mhz, or for 41 Mhz.

Part of your problem stems from what can be seen in this pic,

http://www.helifreak.com/download.php?id=19493

Right under the muffler is an antenna. Just on the inside of that frame is the primary coil and magneto for the ignition system of the engine. This is too close for any kind of proper operation.

The other side is not much better, and can benefit from the use of a base loaded antenna as well.

If the interference has persisted even though you have attempted to shield the ignition wire, it obviously has not done any good and should be removed before it causes engine shutdown through arcing through the insulation (right ClayK! :D )

Interference can also be caused by loose hardware, running servo wires next to antennas, loose or bad bearings, and plain old outside interference.

You also mention that you see interference on the 2.4 gig downlink, that is unusual, and I'm not sure that even the engine can cause that kind of interference....

[Helirono]

Ok,

So, has you've seen I haven't got base loaded antenna (Tx not too).

Thank you very much for your informations.
I'll update all points that you've said, and I'll take you inform if interferences has persisted.

Thank you very much,
Renaud SILVESTRI

[rbort]

Some things I see in your pictures that are not good are:

a) antenna running up and back the boom support
b) antenna running parallel or with servo wires running up the boom support
c) antenna under exhaust as Chris indicated
d) shielding on coil - may cause more harm than good.

Try this:

Hang the rx antennas vertically down using a sleeve tube. I do this on my autonomous helis and it works the best to avoid interferance with all the on-board equipment.

When you take off they will hang straight down you you will get the best range this way. They need to be in a plastic sleeve (I get them from the hobby shop) to stiffen the wire so it doesn't swing around during aerobatics or fast flight and flip up and get caught in the main or tail rotor.

Bonne chance!!

-=>Raja.

[Helirono]

But on the floor, the plastic sleeve will be fold and still fold diring the flight if the heli still parking a long time ?

Merci :)

Renaud

[rbort]

Usually I tuck it in between the gear braces to the rear when the heli is not in flight. You can reflex it by hand before flying so it sticks mostly down. It doesn't have to be straight down, it can be in an arc down and to the rear for example.

I found this gives the best range with all the equipment.

You can secure it somewhere well going down and pass the RX wire through it.

-=>Raja.

[Helirono]

I'll test that !

Thank you very much !

Renaud SILVESTRI