I had been thinking of adding FPV to my quad bought from quadkopters. Had bought the FPV kit for a bigger tri but just thought if its possible on this mini quad. Im using a 200mw tx/rx 5.8ghz with stock antenna for FPV.Quad is powered with 2s lipo.Replaced the Multiwii lite FC with Nanowii due to space constraints. LOS was maintained at all times. Quad was flying like a truck and slightly oscillating due to added weight at full throttle.



After watching the video can any FPV'er suggest whats wrong? Some questions I have are

1) Can the 200mw video tx be powered from 2s lipo?
2) What are the grains that can be seen at the beginning of the video on both the sides before flight?
3) Is a power filter absolutely necessary?
4) Is there any minimum distance required between fpv & quad tx,rx respectively?

The vertical lines later seen in video are probably due to voltage sag but Im not sure. Will be trying the same setup with 3s lipo to see if there is any improvement. Also the focus goes out due to loose lens, which Im gonna steady with some hot glue.

1. Video TX can be powered using 2S but the camera needs 12V.
2. The video has lots of noise, i think its power noise not very sure
3. Now this quad does not have enough space on it hence i cannot suggest you to mount FPV and other electronics apart.

I'd suggest to use a 3s, its best for flying and fpv equipment, and LC filter, it's required.
Google sander style lc filter. Super easy to make and I use it too.
U might be having ground loop.
Focus lens a little far. Let image of focus be 20 feet away.
Keep receivers on back side and transmitters front just behind cam.

Okay tried it with a 3s lipo on land and video quality improved significantly . So I will probably have to get a 3s 1000mah 30c lipo. That will also add some punch to the flight characteristics.

Satya I had read somewhere the camera works with 7-12v, thats why tried it with 2s, guess I confused it with video tx or rx. Also powering video rx with 2s to avoid heating.

Pravesh, I have a capacitor (16v,3300uF) bought for APM to smooth en power, will try and hook it up on video tx however dont have ferrite ring. Attached a pic that shows the arrangement of stuff on quad and its as good as it gets. Please explain ground loop in layman's terms.

Amazing use of the little space Sidewinder!!!. Now post us some good video tomorrow with daylight

Im not sure about the working voltage of video TX/camera,
but, i would like to explain something,

if a device works at 12 volt, 3s lipo of 11.1 volt will produce lot of issues(2s too) its always better to take a higher voltage source and step down to 12 volt and give perfect 12v and correct amperage to the device to avoid issues.

some sort of DC-DC converter IC on 3s lipo to boost upto 12v might be helpful. also an LC filter does a good job of filtering the AC noise present in the voltage due to cross coupling from video TX. this could solve grains problem.

Ashok.P

Pradish battery is on the way, so will take some time for a flight.

Ashok,the camera needs steady 12v as far as I read but provides satisfactory video quality till 7v on further reduction of voltage it cuts off, probably low voltage cutoff kicking in. Video tx needs 7-14v. On a 3s I wont fly below 9.9v so I can live with that for now.

Quad is weight sensitive, so adding more weight will affect flight. DC-DC converter,maybe on a bigger multirotor but not feasible on this lil quad for now. The grains went away as I powered it with 3s lipo, now it has interlaced video, but thats probably due to my recording setup(laptop+usb dvr).

Lot of things I can still tinker with, so will begin slowly with a 3s lipo, if the video still presents issues then will add LC filter, then DIY antennas and so forth.

hi. i don't think LC filter required for 5.8GHz 200mw fpv gear(maybe for 900MHz and 1.2GHz). i am getting solid signal w/o filter. you just need to tune best channel on both end. well i am using separate 3S battery for vtx. i read that boscam vrx gets hot if you run over 3s but mine doesn't gets hot just bit warm.

I had similar apprehensions Dharmik, and have gone through discussions where people havent reached on consensus yet. Some suggest to use while some dont. I probably think the issue Im facing is due to shared power line, so will just use the capacitor to see if it improves situation.I am going to power Vtx separately on a bigger bird but not feasible on this quad.

Powered VRx with 2s because of previous bad experience. As the saying goes "Doodh ka jala, chhaachh bhi phook phook kar peeta hai"

okie since you are also powering CCD cam from the same battery, check this video if you have HD wing cam. you can save some juice for quad and vtx.

Quote from: Dharmik on March 13, 2014, 07:21:48 PM
hi. i don't think LC filter required for 5.8GHz 200mw fpv gear(maybe for 900MHz and 1.2GHz). i am getting solid signal w/o filter. you just need to tune best channel on both end. well i am using separate 3S battery for vtx. i read that boscam vrx gets hot if you run over 3s but mine doesn't gets hot just bit warm.

Lc filter is required if battery is going to be under some load and power lines are shared. Doesn't depend on frequency. Not needed for boscam transmitters as they have a power filter in their board to supply to camera.