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Pumpkin drop event

FPV signal loss at ~ 200ft

#1
Hey all,
To start, I'm a NOOB.

My problem is that I loose FPV signal at around 200 - 300 ft. I am using a Skyzone 200 FPV from Hobbyking (Quanum Complete FPV Bundle Set w/ Goggles, 5.8GHz 32ch Video TX & RX, CP Antennas and Camera (PNF))

I have the TX and Camera running off a 500mah 2s and the RX and Goggles running off a 2200mah 3s.

It works great up close, but as soon as a get 200 ft out or up, the signal starts cutting out.

Any ideas on where to start/look?

Thanks!
Miles
 

vk2dxn

Senior Member
#4
Can you post a link for the tx you are using. At a guess I would say that the tx may not be receiving the correct voltage to reach full output power.
Most tx's I have seen require 12v for full output and I see that you are feeding you're setup with a 2s.
 

joshuabardwell

Senior Member
Mentor
#6
If the operating voltage is 7-24, that indicates that it should be fine on a 2S. I'm surprised nobody has asked, but have you ever powered the TX on, at all, without the antenna attached? Are you 100% sure that you're on the same channel on your goggles and your transmitter? The 32 channel transmitters have enough channels that you can be, like, a half-channel over. You still get okay reception up close, but terrible range. Try flipping one channel up and down on the transmitter and see if it improves.
 
#7
I was careful to make sure I had the antennas attached when I powered on. I have heard it's bad if you don't. My antenna does get REALLY hot on my TX right at the connector - not sure if that is normal. In the field the other day I left the TX on a channel and tried every channel on the RX. I found the signal on 2 or 3 different channels and tested the range of all of them. My best range test was 200 ft or so.

Yesterday I tried my friend went out with his gear - He runs TBS. I was able to see his video, but it also started to lose signal at 200 ft.

Maybe my problem is the the RX?
 

joshuabardwell

Senior Member
Mentor
#8
It's normal for the TX to get really hot. Most people are surprised at how hot it gets. Most likely that's not a problem.

From a basic troubleshooting perspective, if you have a friend with an FPV setup, here is a test you can perform:

  • Turn on his transmitter and only his transmitter.
  • Put both of your goggles onto his channel.
  • Walk away until one of you starts to break up.
  • Repeat this test with your transmitter.

Here are some possible outcomes:

  • Your goggles have shorter range on both transmitters -- the problem is your goggles.
  • Both goggles have short range on your transmitter -- the problem is your transmitter.
  • Both goggles have short range on both transmitters -- environmental interference. Move to a new location and repeat the test.

You can also try swapping out antennas between the two of you, to see if that's an issue.
 

makattack

Winter is coming
Moderator
Mentor
#9
If this is the set you have:

http://www.hobbyking.com/hobbyking/..._Video_TX_RX_CP_Antennas_and_Camera_PNF_.html

You should be getting much more range. I'd say about 1K with no obstructions. That said, since you tried to use your VRX to receive from a friend who presumably has an equal or higher power VTX, and got the same cut outs, I think you're correct in looking at a problem with your ground-station.

Have you tried swapping the antennas from your VTX to the VRX and using your friends TBS VTX to see if the range is any better?

If you want to do some range testing on your own, you might do well to buy a 30db attenuator, connect it to your VTX, along with a one of your antennas. Then, using your buddy's and your VRX's, walk together until one of them loses connectivity. If your VRX loses first, you most likely have a bad antenna on that, or the VRX itself may be at fault. If both VRX's lose connection at about the same time, try a different antenna on the VTX to see if you get the same result.

Anyway, that's just how I would troubleshoot without an RF Signal/Spectrum analyzer.

Hope you can sort it out.

PS: Here's the 30db attenuator I use to range test my RF stuff: http://www.ebay.com/itm/Mini-Circui...30-dB-Fixed-Coaxial-Attenuator-/221608924324?
 

vk2dxn

Senior Member
#10
This is the TX

It shows that its operating voltage is 7-24V. Could it be that a 2S battery is just running in the low end of its input range?
Try powering it from a 3s and do a range check, my next question was about powering it on without antenna but I see that this has been covered in a later post. I see that the power requirement is 7-24 but running a 2s is on the bottom side of its range. My tx will still operate down to 10v (10-14v)however it is at a reduced power output.
 

vk2dxn

Senior Member
#13
If this is the set you have:

http://www.hobbyking.com/hobbyking/..._Video_TX_RX_CP_Antennas_and_Camera_PNF_.html

You should be getting much more range. I'd say about 1K with no obstructions. That said, since you tried to use your VRX to receive from a friend who presumably has an equal or higher power VTX, and got the same cut outs, I think you're correct in looking at a problem with your ground-station.

Have you tried swapping the antennas from your VTX to the VRX and using your friends TBS VTX to see if the range is any better?

If you want to do some range testing on your own, you might do well to buy a 30db attenuator, connect it to your VTX, along with a one of your antennas. Then, using your buddy's and your VRX's, walk together until one of them loses connectivity. If your VRX loses first, you most likely have a bad antenna on that, or the VRX itself may be at fault. If both VRX's lose connection at about the same time, try a different antenna on the VTX to see if you get the same result.

Anyway, that's just how I would troubleshoot without an RF Signal/Spectrum analyzer.

Hope you can sort it out.

PS: Here's the 30db attenuator I use to range test my RF stuff: http://www.ebay.com/itm/Mini-Circui...30-dB-Fixed-Coaxial-Attenuator-/221608924324?
Agreed, I missed this post and the part about the possible fault with the ground station.

You could not have said it better
 

joshuabardwell

Senior Member
Mentor
#15
Would indicate a impedance mismatch between the tx and feed line, try another set of antennas
Good catch. I have seen it happen that a person screws an RP-SMA antenna to an SMA jack. There is no center pin then, but the RF emissions may be strong enough to "jump the gap" and give some output from the antenna. But the vTX in this case has an RP-SMA jack, so this scenario can't happen. Yet another advantage of RP-SMA, I guess.
 

FlyingMonkey

Stuck in Sunny FL
Staff member
Admin
#16
milesgary, can you post pictures of your set up?

Take the antennas off the tx and rx and show pictures of the inside of all four connectors.
 
#18
milesgary, can you post pictures of your set up?

Take the antennas off the tx and rx and show pictures of the inside of all four connectors.
Here is the TX side on my quad image6.JPG image4.JPG image3.JPG

I included the actual quad in case my positioning of any pieces would make a difference.

And the RX side image5.JPG image1.JPG image2.JPG

By the way, I split the plastic covers open on the TX and RX antenna. The TX is a "3 leaf clover" and the RX is a "
4 leaf clover". Not sure if that makes any difference.
 

Flat4

Senior Member
#19
Here is the TX side on my quad View attachment 35692 View attachment 35693 View attachment 35694

I included the actual quad in case my positioning of any pieces would make a difference.

And the RX side View attachment 35696 View attachment 35697 View attachment 35699

By the way, I split the plastic covers open on the TX and RX antenna. The TX is a "3 leaf clover" and the RX is a "
4 leaf clover". Not sure if that makes any difference.
As others have stated I would try a different set of antennas if possible. I've used a set that looks just like yours that I got for like $10 off ebay. They were terrible and gave me very similar results to what you are getting. Switched them out to set of ibcrazy cp antennas and all my range issues were solved.
 
#20
Ok, an update.

This week I flew a few times and I think I figured it out today. However, this is what I tried and in the order I tried it.

1. New location: Result - a bit better, maybe 50ft more range. But that was on open pasture with absolutely nothing around. If I had to fly there every time I did fpv I could find myself getting bored very quickly.

2. Different antennas: A friend let me borrow his Fatshark 5.8G antennas - No change

4. Power from a 3s: This was done after I found my range steadily decreasing as the 2s I was using was loosing power. Result - My range is still not 1.5K, but it can go fairly far.

I also found that I have a short in the video cable that transmits signal to my screen. The flickers look identical to what I see when I lose signal from the TX.

My next purchase will be a set of nicer antennas - My hope is that as I upgrade items, the pieces I get work with what I have. That way I won't have to buy all new gear.

Thanks again for all the words of wisdom!