Disappointing range DEVO 8s, would deviation help?

I have a multirotor (DJI Phantom) and decide to change the stock TX/RX with my DEVO 8s (I use it to fly ladybird and Mini CP), I can say I am really disappointed with the range that I have, it is even less than what you have with the stock TX/RX where everybody agrees is crap. At around 200/300 meters I start to have glitches so of course I do not push further.

On my power screen I am on the maximum power: +20 DBM (I have the stock firmware for the moment)

Has anybody experience of improving range after moving to Deviation firmware. I am so disapointed that I am even thinking to go with Futaba T8J.

Any thougts?

Hi FDR.

I am using a RX1002, look at the picture, both antennas are going on opposed legs. It is my first installation of a RX but I guess should be OK.

Let me know if you have any comment.

M

The antennas should be arranged in a right angle to each other, e.g. one (the last 30mm) parallel to the ground, the other pointing to the ground.
For a Phantom used as a video platform (I guess you do not fly 3D) it will be even better to arrange both in parallel to the ground, but in a 90 degrees angle to each other.
The transmitter antenna may not point directly to the quad. If you arrange the rx antennas as described above, the tx antenna should be in the same plane as the revceiver's - means also parallel to the ground. With this construnction you will always have the strongest signal at the receiver.
Having both rx antenna in parallel as it looks alike on your photo is quite the same as if you have only one - both will receive the same signals.
Having them orientated as I wrote above you will never have both pointing to the transmitter and you have the best signal.

If you have both rx antennas mounted vertical (bad idea as said), You must have the tx antenna vertical too - they always must have a common plane. If you have rx and tx antennas in a 90 degrees angle to each other you will have a minimal signal.

Hi rbe2012.

Thank you very much for the clarification, now I realize I really didn't get the note about the 90 degrees, i thought is was in relation to the RX.

I need to see how to practically achieve it.

M

FDR wrote: Yep, it looks OK.
They might be installed with a bit more different angle, but since it's a quad, it usually fly horizontally...
Where is your transmitter's antenna pointed?

I usually point it horizontally bending the antenna to the left or to the right.

So you do not thing the short range is due to both antenna being in parallel as rbe2012 was pointing out?

Colombus

Unless you fly 3d, your antennas are fine vertical as they are on the picture.

Just make sure your tx antenna is also bend up vertical and held 90deg with the line of sight to the quad.

Do not place one 90deg or horizontal, it will effectively disable that antenna while flying in a horizontal orientation.

FDR wrote: No, then those positions are not too effective.
The antennas of the tx and rx should be parallel for the maximum range.

If you have your rx antenna vertical, so you should point your tx antenna up.
If you bend it horizontally, you should arrange the rx antennas like RBE described.
However don't bend only the end of the wire (without the shield) to horizontal direction, but leave some shielded part with it, and don't bend it sharp...

If i got it right, then the easiest will be just to orientate my TX antenna up, then it will be parallel to both RX antennas. It will be equivalent to what rbe2012 was saying to place both RX antenna horizontally and point the TX antenna horizontally. Is that right?

I will try moving my TX antenna up and see if this is improving my range.

By the way FDR is there any improvement with Deviation in terms of range, TX power?

Thanks to everybody for your great feedback.

I've learned something new.... Which is great.

I will try first changing the orientation of my TX antenna, and once I have more time I will go with Deviation.



M

Today it has been very windy to flight so I decide to make some test and results are quite interesting.

I've reduced the power of the Devo8s to -5 Dbm (minimum) and set the TX antenna horizontally I've placed the Phantom on the ground (perhaps this will make my test not very valid, who knows) where the status lights where well visible and I started to walk away with my body between the TX and Phantom.

I arrived to the point where I had flashing yellow lights (meaning that TX and RX were not talking), it was just the point where going backwards one or two steps the flashing yellow lights will top, then I moved the TX antenna upwards, as recommended, (given the position of the RX antennas), and there was not difference, yellow flashing lights continue. The only thing that made a difference was increasing the TX power to 0 Dbm, this made flashing lights stop.

I've repeated the test this time always facing the Phantom going backward, and with the tip of the TX antenna pointing the Phantom, when I had flashing lights, I moved the antenna up, and yello flashing lights stopped, moved the antenna horizontally and yellow flashing lights stopped, I've moved antenna to point directly the Phantom and yellow flashing lights started again, increased the power of the TX and yellow flashing lights stopped

In conclusion: The only TX antenna position that really has a bad effect for the signal was with the tip of the antenna pointing directly to the RX, between having TX antenna horizontally or vertically pointing up, it seems to be the same. Increasing TX power has a positive effect as expected.

Does it make any sense?

M

Yes, I am not an antenna expert but my understanding is that the tip of the antenna and any region moving up from that point will have the weakest signal as the radio waves propagate outward from the sides of the antenna, so pointing the antenna directly at the RX will have the least range.

Does that make sense?