Rubbish FPV video on TBS Unify Pro

[Roandb]

Recently added a few parts to an existing FPV build. New motors and 4s to 6s battery jump. All of a sudden my FPV video is rubbish, very low penetration and I got a max of 700ft open field test (sounds far but it’s really not).
I’m running a TBS unify pro at 500mw with a TBS triumph pro on the quad end, in the goggles I have a menace patch and then a TBS triumph.
Also installed crossfire in the controller (no problems there) and the receiver in the quad is relatively far away from the VTX.
Considering people can get a few km out of this setup a few hundred feet is very disappointing.
I’ve changed TX and RX antennas on the video side of things, done tests with motors on and off, controller on and off, used previous batteries, ran the vtx off another power source, (which made things worse as camera probs wasn’t grounded to same as VTX). All these things listed made no difference, I was going to install capacitors but a test without motors spinning concluded it would be pointless.
Running out of things to test, is my VTX fried ?

 

[FDS]

Are you using a pigtail? Those can wear out over time and changing them can have a dramatic effect.
You should have a capacitor on the main battery input to the FC. These can come loose over time or a leg can break out, which makes the feed go very “liney.”
The Rush Tank VTX is very good if you decide on a replacement.

 

[ElectriSean]

As FDS says, connections are where I start checking things. Another thought is on the VRx, are you sure the diversity is switching? 700' is decent for an omni, but if the patch never gets used...

 

[LitterBug]

I've had a few of those Unify Pro boards that the pigtail connector "fell off". Would not be surprised if you didn't have the same issue. They didn't seem too eager to replace the boards, but rather recommended just soldering directly to the board. In the end that's what I did and haven't bought any more since. There are plenty of other options.

Cheers!
LitterBug
LB

 

[Roandb]

Yea man I running a pigtail, that would make sense why it works but not completely.
I’m not actually running the VTX off the FC if that’s what you mean, as Kiss FC has a max regulator of .5 amps and I needed slightly more so I got a Matek systems FCHUB regulator PDB.

 

[Roandb]

Diversity does seem to be working I think I did a check with the the two antennas switched around, and to be honest I think the diversity is all ready on the patch at close proximity as if I move my head around I get more static

 

[Roandb]

I've had a few of those Unify Pro boards that the pigtail connector "fell off". Would not be surprised if you didn't have the same issue. They didn't seem too eager to replace the boards, but rather recommended just soldering directly to the board. In the end that's what I did and haven't bought any more since. There are plenty of other options.

Cheers!
LitterBug
LB

Yo Litterbug, I think that could be a very plausible reason for the lack to of range, however surely without a solid connection the VTX would just fry as the antenna is an essential part of the circuit.
I can run the VTX for a few minutes without any issues

 

[LitterBug]

It's worth a check. This is a well known problem with these boards. I had the board shrink wrapped. When I pulled that off, only one ground tab was still solidly connected.

Cheers!
LB

 

[Roandb]

It's worth a check. This is a well known problem with these boards. I had the board shrink wrapped. When I pulled that off, only one ground tab was still solidly connected.
View attachment 152913

Cheers!
LB

Nah my connection is sweet, I checked ground through the pig tail too looks ok, any other suggestions?

 

[PsyBorg]

Its hard to tell from the above picture but it looks to me like that board has the same issue some of the older Lumenier boards had with cold solder joints. That connector that has TBS written on it is what I am looking at. The Lumenier boards had signal degradation right up until that connector totally popped off. Try re whetting those 4 joints and see what that gets you.

EDIT.. If that does not help let us know how you are powering the VTX. I know the jump from 4s to 6s on anything we build has a HUGE spike in signal noise. If you are powered from vbat then that is more then likely your issue. If you are running off filtered 5 -12v regulators are you powering the camera of the VTX or another source. Finally how is your video signal wired from camera thru FC to VTX for the osd. If they are grounded separately on different regulators then you should probably move the camera ground over to the VTX ground.

 

[Roandb]

Its hard to tell from the above picture but it looks to me like that board has the same issue some of the older Lumenier boards had with cold solder joints. That connector that has TBS written on it is what I am looking at. The Lumenier boards had signal degradation right up until that connector totally popped off. Try re whetting those 4 joints and see what that gets you.

EDIT.. If that does not help let us know how you are powering the VTX. I know the jump from 4s to 6s on anything we build has a HUGE spike in signal noise. If you are powered from vbat then that is more then likely your issue. If you are running off filtered 5 -12v regulators are you powering the camera of the VTX or another source. Finally how is your video signal wired from camera thru FC to VTX for the osd. If they are grounded separately on different regulators then you should probably move the camera ground over to the VTX ground.

FIXED!!!!! It was the pigtail where the cable connects to the sma was a dodgy joint, all sorted, but onto the next problem mid throttle oscillations....

 

[PsyBorg]

With jumping from 4s to 6s you have to detune A LOT. Other wise youll be buying more motors and esc's.

What are you flying Betaflight or KISS?

 

[FDS]

Ha, it was the pigtail. Sometimes the simplest things are the issue! Glad to hear you found what was wrong.

 

[Roandb]

With jumping from 4s to 6s you have to detune A LOT. Other wise youll be buying more motors and esc's.

What are you flying Betaflight or KISS?

Flying kiss bro, I did lower the pids a lot, ran a static test on bench and I’m getting a lot of vibrations in the 1/3rd throttle range. Had tape under the arms, switched to tpu 3D prints, still loads of vibrations. You can hear the motor harmonic too, and feel it when you put your fingers on the frame, then with props on it’s even worse. Again you can see it when flying and hear the jolt.
I‘ve ordered soft mounts for the FC, but really I don’t know if it’ll fix it it’s a lot of vibrations, considering sending these xing 2306s back or getting rid of my current frame which is a knock off stingy v2. Id point the finger more at the frame but considering I’ve flown it for 4 months solid with no issues on lumenier motors I think it’s the new xing motors. We’ll see

 

[FDS]

I think you have insufficient moustache for Kiss to work on 6s, you are likely still running the 4s ‘tache.

 

[Roandb]

I think you have insufficient moustache for Kiss to work on 6s, you are likely still running the 4s ‘tache.

I’m working on the ‘tache haha it’s so tempting though, I smacked steele’s pids in and it feels good and really snappy but loads of small oscillations at the same time grrrr

 

[PsyBorg]

On the KISS wiki it states to ONLY soft mount the FC with the supplied o rings. No other soft mounting is necessary.

The Xing motors are like the Emax and have way stronger magnets then the lumenieers. That is where the change comes from. The motors are probably fine. 6s is always a huge pain to set up as the voltage spikes drive everything bonkers. Thats why I stopped at 5s. Much easier to tune and unless you are racing at the national level the reduced current draw to get a few more seconds flight time vs the added weight and cost isnt worth the aggravation to be honest.

Lower pids specially on yaw access. Adjust your rates for low RC rate and then use rate to up DPS for how aggressive you want turns to be. Mid throttle oscillations can be tuned out with TPA.

BTW cookie cuttering some one elses pids is pretty much useless. EVERY quad built including exact clones will never use the same tune as each has its own specific quirks. They can get you in the ball park but rarely ever work the same way as on the original.

 

[Roandb]

On the KISS wiki it states to ONLY soft mount the FC with the supplied o rings. No other soft mounting is necessary.

The Xing motors are like the Emax and have way stronger magnets then the lumenieers. That is where the change comes from. The motors are probably fine. 6s is always a huge pain to set up as the voltage spikes drive everything bonkers. Thats why I stopped at 5s. Much easier to tune and unless you are racing at the national level the reduced current draw to get a few more seconds flight time vs the added weight and cost isnt worth the aggravation to be honest.

Lower pids specially on yaw access. Adjust your rates for low RC rate and then use rate to up DPS for how aggressive you want turns to be. Mid throttle oscillations can be tuned out with TPA.

BTW cookie cuttering some one elses pids is pretty much useless. EVERY quad built including exact clones will never use the same tune as each has its own specific quirks. They can get you in the ball park but rarely ever work the same way as on the original.

I’ve remounted the fc with lots of rubber underneath it with the nuts on top pressing hard on the fc. It’s a bit better but I’m still getting a lot of mid throttle oscillations at a certain rpm. I think I’m just gonna get some new motors. I did a test with no d or i gain and I was still getting the standing wave within the quad causing a nasty sound, obviously it was very minor as I had no high gains. As soon as I turned any gains up the vibration was clearly visible through the camera.Yes the frame is probably causing some problems as it’s not genuine, but I’ve ran lumeniers with no problem, and now problems with Xings. Maybe some lumenier 1750kv Johnny fpv instead of the xing 2306 1700kv? I could probably tune it out but the source of the problem needs to go which is the motors, at the end of the day surely they are causing the vibrations. Even without a PID loop these motors are noisy