Improving VTX / VRX Signal

[NorcoT]

Hello all, so I previously used the Fatshark Predator V2 kit which was great but I didnt get on with goggles so I sold the kit. Recently I decided to build a cheap FPV setup, purchased an Eachine VTX&Camera, a Boscam VRX and a cheap monitor from Banggood.

It all arrived and I test drove it this weekend, picture quality is great for the price .. when the quad is simply sitting on the ground. However when flying I have two problems:

1) Signal Quality - When i start the motors I get some minor interference which i';m guessing is from EMF interference and also stability of power supply to the VTX/Camera. When it';s flying the interference increases as the motor speed increases.

2) Range - The 200mW transmitter is fitted with the standard antenna, I get about 200-300m before the signal goes. However this is very dependent on the orientation of the quad. Currently the VTX antenna sits at the back of the quad just beyond the motors and its sticks up just above the props.

Im looking for some guru advice on how to improve those two aspects and what kit I should use. So far I have:

To improve signal quality - Add battery filter (need advice on which on) to the VTX/Camera, re position the antenna (where to?)

To improve the range - New antenna (Skew Planar?)

Any advice before I start purchasing things would be great!

[Soler]

Hi,

The Eachine VTX and Boscam VRX are on the same spectrum so they should be compatible.  Have you tried choosing a different channel to see if that gives better results?

For the signal quality are you able to test using a second battery?  That would give you an indication if the interference is being caused by interference on the power line.


For the Range what type of antenna';s are you using,  are they the standard rubber ducky ones?  I recommend the Spiro net one from fatshark as these have worked really well for me.

Thanks

[Paul01]

Horizontal lines are caused by motor interference, you can fix it using a low pass filter. With regards to better aerials I would highly recommend you get a pair of skews from Gav on this forum.

[kilby]

Should be quite happy at getting rubber ducks to work at around 300 metres

Definitely get a set of decent antennas, and I do recommend the ones that Gav makes

[NorcoT]

Hi,

The Eachine VTX and Boscam VRX are on the same spectrum so they should be compatible.  Have you tried choosing a different channel to see if that gives better results?

For the signal quality are you able to test using a second battery?  That would give you an indication if the interference is being caused by interference on the power line.

For the Range what type of antenna';s are you using,  are they the standard rubber ducky ones?  I recommend the Spiro net one from fatshark as these have worked really well for me.

Thanks

I';ve tried a couple of channels with slight variations, the Boscam receiver I have only has 8 channels to choose from but i';ll try a few more and compare.

Great idea about the second battery, this should help identify if its the motor interference or power supply stability (or both) that is degrading the signal. I have other lipos, not sure it will fly with a second lipo but should be able to throttle up enough to test.

I';m currently on the rubber duckys, planning an upgrade. From advice i';ll take a look at the spironets and gavs antennas.

Horizontal lines are caused by motor interference, you can fix it using a low pass filter. With regards to better aerials I would highly recommend you get a pair of skews from Gav on this forum.

Yeah its horizontal lines that i';m getting, anything special to look for on the filers? I';ve only ever used the one that came with the FatShark kit in the past. Would one of those work if I rewired it for the Eachine? Or is there something better?

Should be quite happy at getting rubber ducks to work at around 300 metres

Definitely get a set of decent antennas, and I do recommend the ones that Gav makes

Yeah I can get about 200-300m with the rubber ducks, but signal is quite variable depending on orientation of the quad. I think my antenna is perhaps in a crap position and being obscured by the frame / motors too easily when flying about. Its on the rear of the frame, if I fly straight out signal is good for ~300m. If I fly nose in the signal is bit intermittent and I get shorter ranges.

[Hands0n]

For an LC filter something like this will do you fine: http://www.hobbyking.co.uk/hobbyking/store/__68127__L_C_Power_Filter_1_7A.html

They';re available on EBay for three times that cost

Other souces on-line also ...  They';re very effective, compact and lightweight.

[NorcoT]

Do BEC';s work in providing a cleaner power source? Or does an L-C Filter do a better job?

[bazzerh]

just a simple half inch ferrite ring works quite well, coil your +v for your fpv gear around one to get rid of most motor noise. if you need more filtering then a capacitor straddling the +v and ground on the fpv power lines close to the ferrite ring should do it. thats a basic lc filter after all.

by the way i';ve bought an eachine combo and the motor noise is worse than any other vtx i';ve used before. cheap for a reason maybe. the cams are awful imo and the vtx is prone to this noise. think i';ll go back to aomway minis (£15 odd from hobbyking) and a nice pz0420 cam. double the price but worth it.

[NorcoT]

Thanks for the heads up. I';m going to try a set of circular polarised antenna from Phil + a lc filter first. If it';s still not up to it I can switch out the vtx and camera for something better in the long run.

Sent from my GT-I9505 using Tapatalk

[Hands0n]

I';m using an Eachine VTX/Camera combo with an RTF Quads LC filter and its working great, zero interference. Prior to installing the filter even the FatShark VTX was being smashed to pieces.

Sent from my HTC One_M8 using Tapatalk

[NorcoT]

I';m using an Eachine VTX/Camera combo with an RTF Quads LC filter and its working great, zero interference. Prior to installing the filter even the FatShark VTX was being smashed to pieces.

Sent from my HTC One_M8 using Tapatalk

Great to hear :) I';ve just ordered myself an LC Filter from HobbyKing, only about £4 including delivery, and a set of High Precision Circular Polarised Antenna from Phil at Makeitbuyit for about £20. I did look at cheap antenna from HobbyKing too but at £3 for the set I was a bit skeptical about the quality..