Turnigy 9x Broken Antenna

[mmeyer]

I went out flying today and ended up somehow crashing and snapping the antenna wire in half on my Turnigy 9x receiver.

Is it possible to fix this? I have read that the length of the antenna is incredibly important so if it is fixable, how do i do it and what exact length do i need to have the antenna at?
If fixing is not possible do i have to buy a completely new receiver or is it possible to buy an antenna like this one:
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=16666
and retrofit it to the receiver?
On a related but unimportant note has anyone 3d printed cases for receiver electronics before? I find the standard case quite annoying and difficult to use and was wondering what people thought of this.

 

[Bolvon72]

Pop the case open and see if it is soldered to the board or if there is a gold connector. If you have the connector it's not a problem, unplug one and plug the other in. If it is soldered, it is possible to clip and solder the same one on but it's touchy. You have to make sure the outer shield and inner conductor is spaced enough apart. I would have to go with a replacement myself if it is soldered.

 

[mmeyer]

It is soldered unfortunately. Could i in theory get a female gold connector and solder that to the board and then use the antenna? Would that be easier or just too much effort?

 

[Bolvon72]

I just looked at a similar connector on a donor tx I took apart for a mod I am doing on a 9XR and it looks beyond my soldering skill, but it would work in theory. You could go with a replacement and save this for a plane you would keep close, like I do with my nutball, never really leaving the backyard with it. Do a range test and see if you can get any distance from it.

 

[FinalGlideAus]

The part under the red heat shrink does all the receiving. The part you broke does not matter in length as it is shielded. If you joined the wire back together you would need to be sure it was all shielded again. At minimum I would go for a the replacement antenna you mentioned but the soldering may be hard to do if you're not good at it. Can you get someone to do it for you? It may not seem like much but the entire control of your aircraft rests in that piece of wire and those electronic parts connected to it that you may fry if you overheat the board when soldering it on.

 

[peddiparth]

I have the same problem with detached wire. Though it is detached, I still bind to the transmitter.
I will try the soldering route as I have a weller.
How would you mount this free hanging wire on a plane/tri/quad to avoid the snapped wire?

 

[FinalGlideAus]

It may work up close but as soon as you fly away you'll find out the hard way. The end bit is a tuned length of wire (tuned to 2.4ghz) so it's not a random length.

Where to mount it so it wont get damaged is a hard one to answer. It very much depends on the individual aircraft but you really should be more interested in mounting it for the best possible reception. After all, a good antenna is no good if it can't pick up a signal.

Check my post at the end of the "Tricopter LEDs Power source?" thread for more info on antenna positions.

If you guys do try to solder a new antenna on make sure you do a PROPER range test first

 

[jhitesma]

The shielded feed wire isn't a radiator...but that doesn't necessarily mean it's length isn't important. Depending on the RF design of the circuit and the antenna design even a shielded feedline can play an important role in matching the impedance of the antenna to the RX.

I've had mixed results repairing similar breaks myself. The soldering is tricky and could well play a factor in the reduced range I've experienced after most repairs. But it could also be the feedline is a matched length in this case or the bit I re-used may have happened to be a length that happened to match an unpleasant harmonic.

I posted more info about repairing this kind of break in this thread last week: http://forum.flitetest.com/showthread.php?7773-Receiver-antena-wire-fix-for-Turnigy-9x8Cv2

 

[FinalGlideAus]

Good point Jhitesma. That little wire is rather more important than some people give it credit.

 

[jhitesma]

Yep, it's also IMHO a major liability of the 9x RX's. It's just too thin and cheap considering the weight of the antenna on the end. That copper tube counterpoise is heavy. And that wire is weak. If the antenna isn't attached to something it doesn't take too much of an impact for the inertia of the antenna to damage the wire. Though even when I've hot glued the antenna to something I've broken the wire when the part of the airframe I attached the antenna to and the part I attached the RX to decided to part company after a less than gentle "landing".

 

[kah00na]

I had the same thing happen with one of my receivers. The red part flew off some where during my flight and I could not find it. I continued to use the receiver until a new one I ordered arrived. I mostly flew in close with a FT Bloody Wonder and never had any communication problems but everything I read said I probably would. Once my RX arrived, I attached the one with missing red thing to a USB stick that I use on my computer for flight simulators. It works real well there.