Problems with Tx controller and Rx video receiver

Tito1990

Member
Hi guys.

I build an budget FPV racing quad a while ago, first flight flown it without FPV, second flight with the quanum FPV goggles. Crashed the thing with the goggles because I was loosing video. Later fixed the lcd to the transmitter and the video connection is perfect, however when turning on the controller transmitter the video goes almost completely down. I checked that I use a 5.8ghz video link and a 2.4 ghz controller.

Things I already tried:
Different antennas. (cloverleaf style)
Moving the antennas.
Moving the transmitter and receiver.
Changing to different channels.

FPV kit is the 32 channel ones that come with the quanum goggles, the transmitter is the Turnigy 5x I believe... The transmitter is powerd by the lipo powering the screen (12v to 5v circuit board) which was later installed.

Edit: forgot to say the 12v to 5v circuit board (taken from an usb car charger) is also turned on when the receiver and lcd are switched on. It does have some capacitors and a coil on it. However the problem is only when I flick the switch on the transmitter

Any ideas?
 
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Probably not. First time flew it without FPV and only noticed problems with the second FPV flight. Crashed the second time with FPV.

However I doubt it's from the crash. The problem only occurs when I turn on the transmitter.
 
True that. However the cheap circuit board is always on when FPV is on. So that shouldn't be the problem. Especially regarding the problem was before mounting the board.

I could try taking it out again and putting in batteries again. But a TX doesn't draw that much amps right? Normally it runs on 4 AA size battery's.

I'm going to try making it original again. I doubt that it will solve the problem. I'm leaning toward cheap crappy transmitter.... Never had problems with my phantom even with antennas next to each other which also had this mod.
 
Well do you have some way to check some voltages before and after you ' flick the switch on the transmitter'?

You using the BECs off your ESCs for power? How many amps are they?
 
Yes I can check the voltage. Going to try that one out today.

Maybe I've not been clear. I'm sorry for that. English is not my native language. It had nothing to do with the quad side. It's the controller you hold in your hand with a lcd attached to it for FPV. It has nothing to do with ESC or motors.
 
Well, I tried everything today.

Voltage checked. Took the transmitter apart. The antennas had a nice and solid ground.
I tried putting in batteries again. Still interference with the video. Even with the antennas half a meter or more away from each other!
I'm starting to think its cheap and poor transmitter quality. Read something about harmonics disrupting the 5.8 ghz range.

I've read something about high- and low-pass filters. Hobbyking and others do seem to sell low-pass filters. However in my case I think I need a high pass filter (blocking lower 2.4 ghz signals) which seem to be fairly less available, and when available the quality becomes an issue leading to expensive filters. And even then I don't know for sure the problem is solved....

It's very frustrating. I know people use 2.4/5.8 connections all the time besides each other. My vacation is starting soon and I was planning to learn some fpv flying.....
 
Did some random channels but that didn't work. I've indeed seen more people switching true every channel with succes. Going to try that. Fingers crossed!
 
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