FPV range issues -900mhz 500w gopro dx6i blade 450 3d combo

[Wilde Racing]

Hi all newbie here with a few issues. I can't seem to get any range out of my system. Im doing tests at home in my living room and I cans get more than 30 feet or so away from the rx. I've done some searching on here and other forums for the issue. I've checked channels, tried different antennas, installed and moved ferrite rings around, moved the tx and battery around and can get only less range. The best setup so far is if I place the battery near the tx vee antenna with my super custom ferrite extension on the battery leads.

Here are some pictures, nothing is hard mounted besides the camera..

[aaa100]

Just some suggestions, Try without the filter. Have input power to the TX without the antenna? I hear it not good on the TX. You got good battery voltage === 12dc? or close to it. Sorry not much help.

Brian

[AdamM]

Does the system work while NOT mounted to the helicopter?

If everything is spread out on a Table and you take the camera outside, does it function? i would start with only the video system before i introduce the heli (even if the heli is off).

[Wilde Racing]

Thanks guys.

I charged the battery, pulled all of the stuff off the heli, and removed all the ferrite filters. I still get a lot of video drop like before???? This time I checked the range and it seemed pretty good, I was able to walk out of the house and a few hundred feet away from the house. I figured that was good considering the signal had to go through a few walls???

[HopSkipFlop]

Hi, seen something right away. Short story, I am a ham radio operator and back years ago I mounted one of those through the glass antennas on our mini van. It came with way to much coax yet I was not happy with the idea to cut it down. So, I coiled the extra under the dash. The coil was about 3 turns and abt a foot across. The 3 loops where tye-wraped to keep it neat. But I could not tune the swr (standing wave ratio, which improves range, but also keeps from toasting the amplifier).

The reason I think you got better range after you took all of the equipment off of the heli is that you removed the coax coil that was wrapped around the tail boom.

I would look into doing one of the following. Reposition the transmitter so that the coax is not wrapped around anything, unless it is one wrap over several inches. Or look into an antenna like the little ones that look like a ball made of several solid wires that can be mounted on the back of the transmitter. Might need to use a right angle adapter.

But get rid of that coil in the coax. it is called a choke and that is what it is doing with your signal, choking it.

KF0OX, Paul

[HopSkipFlop]

BTW what is that green thing between the radio and the coax? If it did not come with the radio, I would remove it. And pray you have not damaged the final amp transistor. Like I said above, SWR problems can kill little 500mW finials. I know cause I bought a little 144Mhz pocket radio. Could not get down the driveway with it. Replaced the finial amp and I could go several miles away.

[AdamM]

I assumed the "little green thing between the transmitter and the antenna" was a filter.

Correct?

[steve28]

That setup is a major failure , have you flight tested the heli with all that crap onboard I doubt it will even get off the ground and even if it does good luck doing anything with it . Video will be shaking all over

[AdamM]

steve28,

I must say you managed to post something completely useless. Not only was your post extremely rude but you also neglected to offer solutions to problems you are assuming exist to begin with.

The OP is new to FPV and we all learn by trial and error: that's the fun! I've seen success stories with builds like his, so there is no reason to believe that the OP wont have a great time with his build once he figures out the video transmission issue.

Wilde Racing, have you managed to troubleshoot a few problems out of your video Tx?

[HopSkipFlop]

AdamM,

Really my question about the little green thing would be better answered by the OP. Your speculation is just that, and is not really helpful or needed. Please do not muddy the tread with your speculations.

Thanks
Paul

[Wilde Racing]

Originally Posted by HopSkipFlop

Hi, seen something right away. Short story, I am a ham radio operator and back years ago I mounted one of those through the glass antennas on our mini van. It came with way to much coax yet I was not happy with the idea to cut it down. So, I coiled the extra under the dash. The coil was about 3 turns and abt a foot across. The 3 loops where tye-wraped to keep it neat. But I could not tune the swr (standing wave ratio, which improves range, but also keeps from toasting the amplifier).

The reason I think you got better range after you took all of the equipment off of the heli is that you removed the coax coil that was wrapped around the tail boom.

I would look into doing one of the following. Reposition the transmitter so that the coax is not wrapped around anything, unless it is one wrap over several inches. Or look into an antenna like the little ones that look like a ball made of several solid wires that can be mounted on the back of the transmitter. Might need to use a right angle adapter.

But get rid of that coil in the coax. it is called a choke and that is what it is doing with your signal, choking it.

KF0OX, Paul

Thank you, I will try removing the choke (coil wire). During my tests in the living room I also tried removing the antenna and trying the little whip antenna that came with the transmitter with and without the filter.

Originally Posted by HopSkipFlop

BTW what is that green thing between the radio and the coax? If it did not come with the radio, I would remove it. And pray you have not damaged the final amp transistor. Like I said above, SWR problems can kill little 500mW finials. I know cause I bought a little 144Mhz pocket radio. Could not get down the driveway with it. Replaced the finial amp and I could go several miles away.

It is a low pass filter. Im not sure about posting non sponsor links on this forum but here is the description from the website I bought it from...

This Low Pass Antenna Filter is used to reduce the unwanted harmonics on 900MHz wireless video transmitters. Ideal for reducing the video transmitter's radiated EMI / RFI (RF noise) that often causes interference to nearby electronics.


We've redesigned our popular Low Pass Antenna Filter and made it slimmer, stronger, and just plain sexier. Not to worry, our new in-line design has the same great filter performance as before!


Installation is as simple as removing the antenna and then attaching the filter. Works with all popular transmitter antennas that use standard SMA connectors.

Features / Specifications:

• Designed for 910-1040 MHz wireless A/V transmitters.
• Low insertion loss, less than 0.8dB typical at 910MHz.
• Efficient monolithic LC multi-pole topography design.
• Second harmonic attenuation greater than -45dB (-26dB typ at 1570MHz).
• SMA connectors (male / female).
• Inserts between transmitter and antenna.
• Characteristic impedance 50Ω.
  
• Supports RF power up to 8 watts.
  
• Small size, 1.45 x 0.39 x 0.35 inches (35 x 10 x 9 mm).
• Lightweight, 6 grams.

Originally Posted by AdamM

I assumed the "little green thing between the transmitter and the antenna" was a filter.

Correct?

Yep, see above. Thanks

Originally Posted by steve28

That setup is a major failure , have you flight tested the heli with all that crap onboard I doubt it will even get off the ground and even if it does good luck doing anything with it . Video will be shaking all over

Thank you for all the help, I really appreciate it. BTW, I have multiple test videos with the heli in the air and the video is not bad.... I'm playing with head speed and balance to dea with the jello. Please keep the help coming

Originally Posted by AdamM

steve28,

I must say you managed to post something completely useless. Not only was your post extremely rude but you also neglected to offer solutions to problems you are assuming exist to begin with.

The OP is new to FPV and we all learn by trial and error: that's the fun! I've seen success stories with builds like his, so there is no reason to believe that the OP wont have a great time with his build once he figures out the video transmission issue.

Wilde Racing, have you managed to troubleshoot a few problems out of your video Tx?

Thanks, I've been a bit busy to do any more test until this morning. The video was much better for whatever reason, not much change to the set-up. This is still all in the living room testing...

Originally Posted by HopSkipFlop

AdamM,

Really my question about the little green thing would be better answered by the OP. Your speculation is just that, and is not really helpful or needed. Please do not muddy the tread with your speculations.

Thanks
Paul

Well it seems to me that it is a pretty good guess exceptionally if the AdamM has seen the same unit before?

Thanks again guys. I thought this thread had died off quick, the flow on this site seems to be hit or miss I guess? Anyway I'll post up pictures and results of the changes. Maybe someday I'll fly it..

[Wilde Racing]

Here are a few shots. Is it possible to have too many ferrite filters?

[HopSkipFlop]

Hi Wilde,

Ok Great on the low pass filter. Just a bit of education. Note that the filter has abt .8db insertion loss. First just some info leading into more info. Power either doubles or halves per every 3db. So lets say you have a transmitter that produces 500mw (.5W) and you a antenna with 3db gain means you will have an effective 1000mw (1W) signal. Now just for example you install a filter that has a insertion loss of 3db on the same transmitter. Now your effective power to the antenna will be 250mw.
So, with your filter and to make things easy for me, lets say it is a full 1db loss. What we have to do is figure out what 1db equals in this case. So we take 500mw and halve it, and get 250mw (if we had a 3db lows) And now we take that 250mw and divide by 3 to get 83mw per db. So take 500mw - 83mw = 417mw effective power to the antenna.

I see you have removed the choke. What kind of test did you run and what was the results compared to the before removing the choke?

As for the ferrite beads. I would start with only on the power leads to the ESC, Receiver, and Video TX. To many beads will decrease the flight time due to all of the extra weight.

[HopSkipFlop]

Went back and looked at your recent photos.

I see a ferrite on the Go Pro video both at the camera and again at the transmitter. And a lot of connectors. Remember K.I.S.S. The more connectors the more chances of bad connections and drop of voltage across those connections. As I said in earlier post or PM. There is no clear cut installation from one to the next. I would loose the one in the video closes to the Go Pro. And only install if you have problems. Your on the right track, where you have to try different things. Half of trouble shooting is instincts that come with time and seeing things right in front of your eyes.

[Wilde Racing]

Thanks for the follow up. I'll remove some of the filters when I upgrade to the FBL system. Also the system seems to work good so far, I even flew a few times in the back yard...

I was also thinking of going to a three four or five blade head and lower head speed down...



Thoughts?

[HopSkipFlop]

Electronics is my game. Aerodynamics I have very little to no knowledge. Someone else will have to weigh in on the 3, 4, or 5 blade head and slower head speed.

Good luck to you on your project.

[Wilde Racing]

Well, I just tried the set-up. I flew first time FPV but it didnt last long, the wind was blowing and the heli kept drifting further away. The signal started to get fuzy and I got nervous. I tried to find it with my eye and realized I needed to watch the screen not the heli, stuck my head back in and tried to save it.....





The stupid GOPro stopped recording mid flight????? So no crash video.. WTF??

I think I need to work on the ground station. I think I want another receiver with this antenna?

http://www.readymaderc.com/store/ind...roducts_id=296


Any other advice?

[HopSkipFlop]

Well besides the fly bar and main blades messed up some. How is the rest of the air frame looking?

Ok, in that picture are you still on site? in relation to the pick-up. Where did you crash? example off of right front fender or straight back from the tail gate. Do you think you still had control of the heli, but just could not see it well enough to actually fly it. Just want to see if your control RXer was still working. Do you think it was the Go-Pro that quit sending video or the RF link for the video was to weak?

I know that this is a terrible time to bring this up. But I have seen video of guys checking out their equipment before flying. Seen where one guy left his heli on an over pass and then drove down the road with his rx strapped to the roof of the car. Then a portable monitor to look at. Might have a driver drive while you watch the monitor. See how far away you can get. And maybe a servo with a flag on it so that you can move it around to check the control radios at the same time.

As for the yagi. Note that this produces a BEAM that has high gain for say 20 degrees or less. But fly left or right of the Beam and signal drops rapidly. Almost need a tracker software/hardware to swing the beams to track the heli. Where you close to any houses or businesses? 900Mhz cordless phones or cordless security cameras can interfere with your signal.

Sorry to see and hear about the short flight and hard landing.

[Wilde Racing]

Damage to the heli was light considering how high I was before the crash. I was flying in a open field within the housing development. the field is very flat but surrounded by houses so I'm sure there was a lot of interference in the 900mhz range. I started the flight with the helicopter facing away from me Vee antenna facing me, then once I got it about thirty feet up and stable, I stuck my head in my super custom cardboard box you can see in the background that has the receiver taped to the top. I was actual flying it for a second (I've been practicing with the simulator) and began to bank to the left when the video started flickering pretty bad. I still had total control of the heli, just no video. If I could have spotted it when I pulled my head out of the box I could have saved it. Or better yet,if I had a spotter with the ability to take over, but whatever, that isn't an option at this point.

After I posted the link to that antenna, I did a bit more research, it seems a patch might be a better choice?


A range check will defiantly be a part of my pre-flight test next time, I was just in too big of a hurry as usual.

[AdamM]

Aw dang. Sorry to hear about the crash but it looks like the heli isn't too bad. Here's to a quick repair!


How far away do you think you were before it started to cut out?

PS: Awesome Ground station "Box" =D I need to do something like that!