Problem With VTX

tj272004 · Nov 11, 2019

Hello, I'm using a AKK K31P 5.8GHz 600MW VTX and using a GOQOTOMO GC04 Mini 2.8MM 700TVL camera for FPV and I've been having some trouble getting it to work. I'm powering it with a 3S battery and when I use my goggles (Fat Shark Teleporter V4), I cannot seem to find the channel. I know it is not my camera because I tried it out on another drone and it worked fine, but the VTX does not seem to be working. It has options to change the band and frequency and I've tried most of the different combinations and it still does not show. Any ideas what the problem is?

Product Links:
VTX: Amazon.com: AKK K31P 5.8GHz 600MW SMA Female 5V Out for Cam Mini FPV AV Transmitter with Pigtail: Toys & Games
Camera: Amazon.com: GOQOTOMO GC04 Mini 2.8MM 700TVL NTSC Automatic gain CMOS Camera for FPV Drone: Toys & Games

rtkDarling · Nov 12, 2019

What are you powering the VTX from? It should be Vbat, if you're bringing in 5V it may get lights but not work.
Also, don't use the autosearch. The VTX has a display that says what channel it's on.

You can rule out the camera because if the camera doesn't work you'll still get a black screen with OSD from the VTX, I assume you're just getting static?

tj272004 · Nov 12, 2019

I’m using a 3S battery and connecting the two wires from the battery cable from the VTX directly to it. I’m doing the FPV setup completely separate from my FC and I am not using an OSD. I assumed the battery would power the VTX and then the VTX would power the camera and it would display the footage on the band/channel combination that is listed on its
LED.

rtkDarling · Nov 12, 2019

That should work the way you describe... I'm not sure what's going on but I'm thinking about it. Post back with anything you try, or any other details that come to mind. I've never use Arduo pilot, but sometimes little details can reveal a larger picture.

The question is: without a camera or any input, will a VTX still project a black screen? If the answer is yes then you likely have a bad VTX. I'm going to look up the answer to this question

RPR · Nov 12, 2019

Unlock the VTX?

tj272004 · Nov 12, 2019

So I fixed the problem:
What I think the problem was was that the camera had an operating voltage of 12 Volts (but due to a customer review, I had though it was 5V-12V), and the VTX only gave out 5V to the camera. So to fix the problem, I took out the + and - (red and black) wires from the 3-pin connector coming from the connector and then soldered each wires to the same color wire coming from the VTX pigtail so that the camera and the VTX were both getting direct power from the 11.1 Volt battery and the only wire connecting the camera to the VTX was the signal wire (yellow wire). In addition, it did not work right away, I do not know that much about FPV frequencies/channels so I just flipped through the channels on the VTX via the switches and then flipped through the frequencies on my goggles until I eventually found it. I don't know if this is what I was expected to do, I just assumed that because all of the wires fit perfect together, meaning M to F, that they would work swiftly. So, rookie mistake I guess, but at least I got to practice soldering!