Jump to content
Sign in to follow this  
oxxyfx

Interference from Nitro Engine

Recommended Posts

Hello,

I built a Northstar with video gear in it. The Northstar has an OS 50SX engine on the tail, and the regular RC circuit for piloting.

Pictures here: Northstar The frst 8 pictures are mine.

The video circuit is a second completly independent circuit, it consist of:

- Camera from supercircuits.com

- Black Box from act-labs

- 2x2 cell Lipo for a total of 14.8V

- Airwave 500mW transmitter

- powerpanel using LDO's supplying 5V, 9V, 12V

The RC system is powered separatly from a 4.8V Nicad. The 2 circuits are completly independent of each other.

Saturday I powered up and started the plane for a test flight. I did not use the video gear for the flight, but I powered it up while in the ground and breaking in the OS engine.

While in idle, there were no problems. Once once I applied some thrust - around the 2/3rd of the thrust the Video went black. Increasing the thrust to the 2/3rd showed some interference lines, not too many - I wonder if those were from the engine or because the vibrations.

Is it possible that the engine on high thrust would generate such interference that it would blank the video signal?

Thanks, Ox.

Edited by oxxyfx

Share this post


Link to post
Share on other sites

Thanks Terry.

Could there be any kind of interference created by nitro engines? I thought that interference can be created only by electrical engines / ESC's...

Share this post


Link to post
Share on other sites

Metal to metal vibrations can cause interference with R/C receivers but I don't think it will effect your video TX. Try removing the video TX and holding it next to the engine when running. If you have a mic fitted this too can cause interference with a loud engine.

Terry

Share this post


Link to post
Share on other sites

I knew about the microphone, so even though I wanted to install one - i didn't. I will do some tests, once the weather gets better and I'll report back on my findings.

Thanks for your help.

Ox.

Share this post


Link to post
Share on other sites
Metal to metal vibrations can cause interference with R/C receivers but I don't think it will effect your video TX.

I agree with that. The EMI/RFI noise from such things does not readily extend to the microwave RF band. Most of that sort of noise is well under 400Mhz.

In all the cases where I can recall that someone was convinced the 2.4Ghz based video problem was EMI/RFI from motors, props, heli blades, and the like, the real problem was always something else. Vibrations can indeed affect some transmitters and other video gear (sometimes from very odd sources). But it is mechanically induced, not via "RF." However, I never say never, so YMMV. :)

Share this post


Link to post
Share on other sites

Thanks. I am suspecting vibrations as well, being a mechanical eng. I still very well remember my vibration labs at the univ. where we did very interesting test by inducing vibration and reaching resonant frequency of different objects.

Also fact is that there seem to be no interference at all during idle and up to about 6000-7000rpm. The plane was on a stand (table) and not on the ground - and I indeed heard vibration related humming from the plane's body around the middle of the stick. That is probably when everything together gets in resonance...

The transmitter is pcb mounted on wood (balsa), and there is no rubber or foam or other material which would stop the vibrations - also the camera as you can see on the pictures is standing on 2 servo horns, so that may very well translate some vibrations to the camrea body as well.

Anyway, I need to do some more testing to find out what do I have to isolate, foam, rubber to lessen the vibrations on the electronic components.

Thanks.

Ox.

Share this post


Link to post
Share on other sites

You might look at the transmitter "sardine can". I had a vibration induced video interference and in my case the transmitter can halves were not fitting very tightly.

I soldered spots around the can and that problem ceased.

I found this by tapping on the "can". Just a thought.

Joe

post-5-1176768504_thumb.jpg

Edited by joekadet

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this  

×