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Spektrum Integration with AR7700 Receiver
Posted: Tue 17. Apr 2018 15:03:30
by Kluftinger
Hello,
I'm using a Spirit pro with the new SLRX receiver from Spectrum AR7700 connected to the rudder port.
A Hobbywing Platinum V4 ESC is connected to Aux1 and the single yellow wire is connected to the PIT post to feed the signal for the Spirit governore.
The telemetry is delivered by a Unisens-E unit via TM1000 and Xbus-adapter to the AR7700.
What I'm missing now is the integration of the Spirit system in the telemetry.
The SPM4649T (satellite) signal is usually hooked up to the AIL post but it requires a dsmx adjustment in the software.
Would it make sense to connect the signal from the RemoteRX outlet of the AR7700 to the AIL post and still leave the mode in the software at SLRX to get the integration tab in the telemetry?
Thanks in advance for any hint.
Kluftinger
Re: Spektrum Integration with AR7700 Receiver
Posted: Sun 22. Apr 2018 9:55:56
by ZeXx86
Hello,
I am sorry for late reply.
I am afraid, but it is not possible to use both SPM4649T and AR7700 together. Even that they both appear to be SRXL receivers, SPM4649T is not in reality. It is communicating with the same protocol as a Spektrum satellites, but messages that it is receiving from unit is in SRXL format.
On the other hand AR7700 can't process these messages.
So you have to use Spektrum satellites with SPM4649T (or just one SPM4649T) and connect it according to:
http://manual.spirit-system.com/index.p ... ntegration
Re: Spektrum Integration with AR7700 Receiver
Posted: Sun 22. Apr 2018 15:29:48
by Kluftinger
No worries, this was no urgent question.
I read in the specs for the AR7700 that it can handle an extra remote receiver, but it didn't say it can be a SPM4649T.
I have quite some issues with the 4649T and the provided RSSI data. The value drops down to 10-20% in a distance of 80m when the fixed antenna of my DX7g2 is pointing at the model. With cable ties on both sides supporting the two antennas (as seen on racecopters) I could gain about 20% for each situation.
I know, RSSI is not a very scientific data in the telemetry, but as soon you read weak numbers, it is hard to ignore them. Some say, RSSI data are only refering to the telemetry reception and the control of the model is still working fine.
So for my small helicopters, I'll stick with the 4649T, but for 450's and up I'll go with regular receivers.
A WiFi modul will then compensate the missing integration for adjustments on the flying field.
Re: Spektrum Integration with AR7700 Receiver
Posted: Sun 22. Apr 2018 19:15:04
by ZeXx86
Ah, thanks for the details.
Regarding antenna - your radio should never point with antenna to the model - in this case the signal transmission is very low.
The antenna is radiating around the rod which mean you should tilt it by 90° to get the best results.
But you can also play with antenna on the receiver and mount them so that they are perpendicular and outside of the model.
Re: Spektrum Integration with AR7700 Receiver
Posted: Mon 23. Apr 2018 7:16:07
by Kluftinger
ZeXx86 wrote:
Regarding antenna - your radio should never point with antenna to the model - in this case the signal transmission is very low.
The antenna is radiating around the rod which mean you should tilt it by 90° to get the best results.
But you can also play with antenna on the receiver and mount them so that they are perpendicular and outside of the model.
Yes, I agree, but the DX7 gen2 has a
fixed Antenna
The old antenna was not really durable but worked very well. The new style is vice versa.

Re: Spektrum Integration with AR7700 Receiver
Posted: Tue 24. Apr 2018 8:09:14
by pachy
Hi... just about my experience, I use 4649T on 325mm and 380mm heli size, I never had a H telemetry value different to zero.
Re: Spektrum Integration with AR7700 Receiver
Posted: Tue 24. Apr 2018 16:58:07
by Kluftinger
Hi pachy,
I never had a "
Hold" issue with the 4649T either. This would mean, the modell lost radio contact and had crashed.
What I see is "
Frame losses" and and very low RSSI values.
I could not find a clear statement from Spektrum, if RSSI is refering to the telemetry or the model control connection.
One user mentioned, he is seeing low values on the receiver telemetry display and higher numbers on the OSD at the same time.
This could mean that the OSD shows in this case data related to the transmitter connection (model control).
So maybe after the telemetry of a 4649T goes away in a distance of app. 150m, the model is still under control for another 150m.
But I don't want to be the test pilot for that with a 450 Heli.

Re: Spektrum Integration with AR7700 Receiver
Posted: Tue 24. Apr 2018 21:44:26
by pachy
@Kluftinger
You can have an hold or more without a crash.
Hold description from horizon hobby
« Hold – a hold occurs when 45 contiguous (one right after the other) frame losses occur. This takes about one second. »