DBS Mod Issues Still/Again

BourgeoisSJC · Feb 22, 2017

I have been struggling with my setup since I performed the DBS Mod. My first tests, albeit short in range, appeared that everything was working. I then decided to do some range test using Litchi Mission functionality.

The first test was 1 Km (70m alt). No issues what so ever. Good RC and Video signal throughout
Second test was 1 Mile (70m alt). Signals dropped around 1400m.
Third test same as second except with an alt of 85m. Signals dropped around 1600 meters

Then my problems started. Several days later I retried the 3rd test without any changes. My RC signal dropped as soon as it was 400 meters from home and did not return until the drone came back and within 400 meters or less from home. The video feed however was smooth as butter till about 1550m' when it froze. Came back at 1450m'

Several other missions at different locations showed the same problem. Seemingly when the drone moved further than 400+ meters the RC signal dropped.

Today I decided I would try to fly FPV and sure enough when the drone was more than 400m away RTH kicked in.

I have opened the remote several times now to check the connections. All seem ok. I am at a loss why I am now losing RC signal so close to home?? Before this mod I was getting 800m at this same location before RTH kicked in. What should I be looking at? I am worried that I may have damaged the remote at one point during the install.

captainmilehigh · Feb 22, 2017

My DBS has been a learning experience also. My range increased dramatically over the stock or windsurfer modded r/c I was using, but one point was apparent with the DBS. Altitude matters greatly. The farther away the drone went, the higher the better. In an unobstructed area that I fly I can get 2 to 3 miles out, BUT, I need to be at 400 feet (or better) altitude for optimum range and signal strength.

Sounds like your DBS is set up properly, but 85 meters may be a bit low. Maybe try a bit more altitude and see what happens? Hope this helps.

Sent from my iPad using PhantomPilots

k9time · Feb 22, 2017

I agree with captainmilehigh.. The best range mod you can do is gain some altitude. Less interference and better LOS.

Sent from my SM-T817V using PhantomPilots mobile app

BryanBTX · Feb 22, 2017

DBS has always said point at AC in LOS. So the higher you go the further you go.

BourgeoisSJC · Feb 22, 2017

The thing is, the tests immediately after I did the mod had no issues with losing RC signal. This problem started (as best I can recall) yesterday afternoon even though I am flying the exact same missions. There are two things I just recalled.

Yesterday morning I flew a one mile long mission over an very muddy, flat farm field. The actual distance was a bit over 5700'. No signal loss what so ever. Today I went to the same location and flew FPV at the same alt. RTH kicked in at 500 meters. Last fall, using only a windsurfer, I was consistently getting 1200m before RTH kicked in. This afternoon I went back to my usual place (where the above mentioned mission took place) and at an alt of 300' I got as far as 500m. Before the mod and at a much lower altitude I would get at least 700m.

Another thing I recall, and hope this isnt a red herring, is that a day or two ago I decided to try out CSC to shutdown the engines. The drone flipped over and I had to quickly shut it off using the left switch down method. There did not appear to be any damage and even the props looked fine. I now wonder though if something on the drone its self may have come lose or damaged.

Lastly, when I lose signal while flying FPV and RTH kicks in should I still be able to see the video feed, altitude, speed and distance parameter which are continually being update despite that "Signal Lost" message? Even more puzzling is when I fly a long mission. I get zero bars for RC signal strength but all my parameters are still being updated on the screen. They only stop once I lose video feed which usually occurs somewhere around 1 mile from home.

captainmilehigh · Feb 22, 2017

Have you done a IMU calibration lately since the flip-over? Something may have compromised them during the tumble.

Sent from my iPad using PhantomPilots

BryanBTX · Feb 22, 2017

It seams to me that I noticed a lower AC signal after this last FW update. Or I just didn't pay attention before.

BourgeoisSJC · Feb 22, 2017

captainmilehigh said:
Have you done a IMU calibration lately since the flip-over? Something may have compromised them during the tumble.

Sent from my iPad using PhantomPilots

No I have not. Sure worth a shot. Unfortunately, I wont be able to do any more testing for a while. The weather is getting nasty over the next few days..

BourgeoisSJC · Feb 22, 2017

BryanBTX said:
It seams to me that I noticed a lower AC signal after this last FW update. Or I just didn't pay attention before.

I stayed with 1.7.n because of all the scary reports on FW 1.8.n updates.

BourgeoisSJC · Feb 23, 2017

captainmilehigh said:
Have you done a IMU calibration lately since the flip-over? Something may have compromised them during the tumble.

Sent from my iPad using PhantomPilots

Did a complete calibration, uninstalled then re-installed dji-go and litchi and rushed out this AM to do another test. At an altitude of 120m (about 400') I lost RC signal before I even reached 400m from Home.

Getting very frustrated not knowing where to look. Wish there was a way to determine where the problem actually was. Controller or Drone? If I was sure the controller was the problem I be willing to go out and buy another one ;(

captainmilehigh · Feb 23, 2017

BourgeoisSJC said:
Did a complete calibration, uninstalled then re-installed dji-go and litchi and rushed out this AM to do another test. At an altitude of 120m (about 400') I lost RC signal before I even reached 400m from Home. Getting very frustrated not knowing where to look. Wish there was a way to determine where the problem actually was. Controller or Drone? If I was sure the controller was the problem I be willing to go out and buy another one ;(

If you get a chance, you may want to note the orientation of the r/c when you lose signal. The further away the drone is, the more precise 'aiming' of the controller must be........especially at long distances. Even a little wiggle by you will affect the signal.

Maybe try shorter distances first, looking at the signal strength on the screen rather than at the drone. By moving the r/c you can see the effect it has on the signals.

Then move further away and try it again. I've found that my signal drops out if I 'aim' the DBS too low. Why, I don't have a clue. Once out of LOS, it's hard to aim it anyway, right?

Edit: Following your other thread also on DBS signal strength.

Sent from my iPad using PhantomPilots

BourgeoisSJC · Feb 23, 2017

captainmilehigh said:
Edit: Following your other thread also on DBS signal strength.

Sent from my iPad using PhantomPilots

Funny thing about that thread is that I created it right after I did the mod. At that time I was always getting 83% (+/-4%) regardless of how I held the drone. The first "long range" (1000m) my signal strength never dropped below 80%. I was happy

Then.... well here we are

captainmilehigh · Feb 23, 2017

BourgeoisSJC said:
Funny thing about that thread is that I created it right after I did the mod. At that time I was always getting 83% (+/-4%) regardless of how I held the drone. The first "long range" (1000m) my signal strength never dropped below 80%. I was happy Then.... well here we are

Yeah, I saw that in the other thread. Strange indeed. After leaving LOS ( yep, I know that's frowned upon) I use the strength meters on the r/c to try to stay pointed at the drone, but even then I lose it sometime. Then the RTH kicks in.

Maybe re-linking the r/c may help as you suggested. Can't hurt to try.

Keep us informed. It could have been a bad ufl connection that you fixed earlier. Wait and see I suppose. [emoji106]

Sent from my iPad using PhantomPilots

BourgeoisSJC · Feb 28, 2017

Good weather to fly today. Relinking made no difference it seems.

My first test flights were above a very flat farm field. Using Litchi I couldnt get any further than 400 meters before RTH kicked in. There was no warning. Signal went from 100% to 0% Tried the same flight only this time I used DJI-Go. Much better event though I kept getting weak signal errors I had time to adjust the position of my controller. Got to about 970m before RTH kicked in. Funny thing is though, I was doing better at lower alt (20m) than at high alt (70m). At the same location, before the DBS mod, I used to get 1200m using the same controller with a windsurfer.

My second tests were at my favorite park and regardless of alt, the best distance was 600m. At the same location, before the DBS mod, I used to get 800m+ using the same controller with a windsurfer.

jwmcgrath · Feb 28, 2017

Wow. I feel your frustration. Watching your thread intently because I've read about range mods til exhaustion and I'm convinced DBS is the way I'm going to go, so I hope this works out for you. Crazy frustrating when a problem isn't black and white.

Jeff

captainmilehigh · Feb 28, 2017

BourgeoisSJC said:
Good weather to fly today. Relinking made no difference it seems.

My first test flights were above a very flat farm field. Using Litchi I couldnt get any further than 400 meters before RTH kicked in. There was no warning. Signal went from 100% to 0% Tried the same flight only this time I used DJI-Go. Much better event though I kept getting weak signal errors I had time to adjust the position of my controller. Got to about 970m before RTH kicked in. Funny thing is though, I was doing better at lower alt (20m) than at high alt (70m). At the same location, before the DBS mod, I used to get 1200m using the same controller with a windsurfer.

My second tests were at my favorite park and regardless of alt, the best distance was 600m. At the same location, before the DBS mod, I used to get 800m+ using the same controller with a windsurfer.

Something's gotta be wrong somewhere. I feel your frustration too. Never have seen signal drop from 100% to 0% instantly. I always watch my signal strength when distance flying because it is usually the pilot (me) not pointing the R/C right. Maybe the more experienced should offer their views. How 'bout it @dirkclod or @msinger..........is it the DBS, the R/C, or maybe the bird? Is there any way to test DBS itself for problems? I'm out of ideas.

Sent from my iPad using PhantomPilots

dirkclod · Feb 28, 2017

As far as distance with mine I fly from a hill top into a valley
So height isn't an issue. I sit with my tx on my lap to hold it steady. 2 to 3 miles is the norm. There is no noise.
Have you tryed changing out the cables that go from your
Tx to the panel. Do you leave it on all the time. If you remove
It as some you might have bent on of the prongs in the connecter. Look at those things.

jwmcgrath · Feb 28, 2017

What dirkclod just said reminded me of all the warnings I've read about MAKING SURE not to turn the power on the RC when the antenna is not connected, or damage can result.

Any chance of that?

Jeff

captainmilehigh · Feb 28, 2017

dirkclod said:
As far as distance with mine I fly from a hill top into a valley
So height isn't an issue. I sit with my tx on my lap to hold it steady. 2 to 3 miles is the norm. There is no noise.
Have you tryed changing out the cables that go from your
Tx to the panel. Do you leave it on all the time. If you remove
It as some you might have bent on of the prongs in the connecter. Look at those things.

Thanks Dirk. As you know, I fly mine over open country too, no noise, and have no issues at 400' out to 2-3 miles like you. I don't understand why his signal drops to 0 almost instantly unless it is a hardware issue. Has me baffled.

Sent from my iPad using PhantomPilots

captainmilehigh · Feb 28, 2017

jwmcgrath said:
What dirkclod just said reminded me of all the warnings I've read about MAKING SURE not to turn the power on the RC when the antenna is not connected, or damage can result.

Any chance of that?

Jeff