I have the Typhoon H Pro. It's my belief that the dual ST16 antennas are for transmitting control data to the H, the little antenna in the center receives data from the antenna that's within the camera and the dual H antennas receive the control data from the ST16. Which antenna sends the drone telemetry to the ST16?
Telemetry transmission antenna?
- Thread starter jandjfrench
- Start date
- Joined
- Jul 4, 2017
- Messages
- 4,258
- Reaction score
- 2,025
Phaedrus
Premium Pilot
If you have a 2 antenna ST16, the telemetry antenna is inside the ST16. If you have the 3 antenna model one of the stick antennas is used.
Telemetry (from the H) transmission antenna? When I first do a normal start the first data the ST16 displays is the telemetry from the H. What antenna on the H transmits this data and which antenna on the ST16 receives it? As there are 2 sets of dual antennas I'm not sure which set is being referred to.
Phaedrus
Premium Pilot
Yep. Still trying to get a handle on things in case problems pop up in the future.
You may be getting two way transmission on the one antenna.
One may be for redundancy
I seem to remember reading somewhere that they added a redundancy circuit in case of control failure
One may be for redundancy
I seem to remember reading somewhere that they added a redundancy circuit in case of control failure
I'd like to clarify my concerns. I've been going over posts and have seen quite a few involving loss of control or the H dropping out of the sky. Most problems seem to be blamed on a loss of power but we don't have the NTSB looking into the causes so It seems that it's up to the users. It may well be a loss of power but a loss of communication may also be a cause.
It appears that my understanding of the communication systems is flawed but my primary initial concern is identifying which antenna transmits the telemetry data from the H to the ST16.
Phaedrus
Premium Pilot
Loss of communication triggers a RTH. Basically a failsafe setting for loss of signal.
Loss of power will certainly stop communication, but that loss is not the cause of a crash. When you lose power the spinny things stop turning and you crash. But they do not stop spinning because you lost communication.
Flight controllers (the brains inside the aircraft) sometimes fail and cause a true flyaway. Sadly more than a few "flyaways" are simply loss of orientation on the part of the pilot who then flies into something. Neither of those are caused by a loss of communication.
About the only concern related to the antennas is they they are connected correctly. They are pretty foolproof. The strongest signal on the 2 longer ones is perpendicular to the long axis. Don't point them directly at the aircraft.
The mushroom in the middle is the camera control and video feed. If you replace that with the flat one included by Yuneec you do want to point that directly at the aircraft.
Make sense?
Loss of power will certainly stop communication, but that loss is not the cause of a crash. When you lose power the spinny things stop turning and you crash. But they do not stop spinning because you lost communication.
Flight controllers (the brains inside the aircraft) sometimes fail and cause a true flyaway. Sadly more than a few "flyaways" are simply loss of orientation on the part of the pilot who then flies into something. Neither of those are caused by a loss of communication.
About the only concern related to the antennas is they they are connected correctly. They are pretty foolproof. The strongest signal on the 2 longer ones is perpendicular to the long axis. Don't point them directly at the aircraft.
The mushroom in the middle is the camera control and video feed. If you replace that with the flat one included by Yuneec you do want to point that directly at the aircraft.
Make sense?
Last edited:
PatR
Premium Pilot
I’d sure like to see some evidence the 2.4 antennas are “one way” because I do not believe that to be true. A typical 2.4GHz RC system employs at minimum a pair of antennas on the receiver side with but a single antenna on the transmitter side. They employ two antennas on the receiver side because 2.4 can be easily blocked by obstacles in the path between transmitter and receiver. Those systems are quite capable of receiving flight telemetry from the aircraft.
I suspect 2.4 antennas on the ST-16 and aircraft are bi-directional.
As for signal loss causing a power off crash, the prospect of that is extremely remote unless a failsafe had been programmed to cut the motors in the event of signal loss. An RC system that loses signal typically continues executing the last command being received unless a failsafe program has been input to do otherwise. As the H has been factory programmed to return to the last known controller position after signal loss the probability of a power cut due to signal loss is zero.
I suspect 2.4 antennas on the ST-16 and aircraft are bi-directional.
As for signal loss causing a power off crash, the prospect of that is extremely remote unless a failsafe had been programmed to cut the motors in the event of signal loss. An RC system that loses signal typically continues executing the last command being received unless a failsafe program has been input to do otherwise. As the H has been factory programmed to return to the last known controller position after signal loss the probability of a power cut due to signal loss is zero.
Phaedrus
Premium Pilot
I agree.
Which I do not believe is something that can be done with the Yuneec products.
Yep.
DCH
Dr. FrankenPhoon
I don't doubt this at all. I was simplifying the antenna layout for the OP's original query. There are even more antennas inside the ST16, but it's best not to confuse the issue any more than necessary.
I believe the only reason it might not make it back is if there is a low voltage fail safe that triggers and emergency landing wherever it is, even if it's returning to home after a signal loss. One can only hope that it's someplace where it is easily retrievable, and not in a tree top or body of water.
Phaedrus
Premium Pilot
To add to Pat's post, most other hobby RC units that have telemetry use a single antenna on the transmitter (controller). It send flight control signals and receives telemetry data. The aircraft typically have at least 2 antennas on the receiver. Both receive control signals and send telemetry data.
The ST-16S has three antennas because 2 are for 2.4GHz flight control/telemetry. The middle mushroom/flat antenna is 5.8GHz camera control and video downlink.
And again very little ever goes wrong with the antennas as long as they are not physically broken or disconnected.
The ST-16S has three antennas because 2 are for 2.4GHz flight control/telemetry. The middle mushroom/flat antenna is 5.8GHz camera control and video downlink.
And again very little ever goes wrong with the antennas as long as they are not physically broken or disconnected.
PatR
Premium Pilot
Jelly side down principle. The odds of a piece of dropped bread with jelly on one side landing jelly side on the carpet is directly proportional to the cost of the carpet.
DCH
Dr. FrankenPhoon
Phaedrus
Premium Pilot
Does that apply to the 16S? As I recall when I opened mine I only saw 3 antennas. 2 control/telemetry and the single video/camera.
h-elsner
Premium Pilot
- Joined
- Mar 23, 2016
- Messages
- 1,947
- Reaction score
- 1,640
- Location
- Bavaria / Germany
- Website
- h-elsner.mooo.com
There is no antenna only for telemetry.
Both 2.4GHz RC (ZigBee) antennas are bidirectional. There are two for antenna diversity. The receiver checks what antenna has the best signal and takes this. Antenna diversity is made to overcome interferences and gaps in the radiation pattern of the antenna.
The minimum radiation (as well as receiveing signal strenght) is on top of the rod antenna. This is the reason why the two antennas should have 90° to each other, i.e. one horizontal and one vertical. Where the ones minimum there the others maximum.
At the two antenna ST16 the internal is horizontal --> the external should be vertical. For the 3 antenna ST16 it's up to you. 90° to each other no matter in which direction is optimal.
There is only one 5GHz antenna for the video downlink and command uplink which is also used for "Dual Band Control Redundancy".
Internal we have another two antennas: One GPS antenna und one 2.4GHz WLAN antenna for the pad mode.
br HE
Both 2.4GHz RC (ZigBee) antennas are bidirectional. There are two for antenna diversity. The receiver checks what antenna has the best signal and takes this. Antenna diversity is made to overcome interferences and gaps in the radiation pattern of the antenna.
The minimum radiation (as well as receiveing signal strenght) is on top of the rod antenna. This is the reason why the two antennas should have 90° to each other, i.e. one horizontal and one vertical. Where the ones minimum there the others maximum.
At the two antenna ST16 the internal is horizontal --> the external should be vertical. For the 3 antenna ST16 it's up to you. 90° to each other no matter in which direction is optimal.
There is only one 5GHz antenna for the video downlink and command uplink which is also used for "Dual Band Control Redundancy".
Internal we have another two antennas: One GPS antenna und one 2.4GHz WLAN antenna for the pad mode.
br HE
Phaedrus
Premium Pilot
This is exactly what PatR and myself think as well. It is also the way every single 2.4GHz RC system I know of works. I arrange the 2 antennas on my ST16S at 45 degrees to the vertical. This places them at 90 degrees to each other. Look at a H+. The two signal/telemetry antennas stick down at ~45 degrees near the gear legs.
Last edited:
Similar threads
