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Thanks for your help and the link. I did a range test on Thursday but my GoPro was out of focus so all I have is OpenTX logs again. They matched what the TX said but I will go again this weekend and get GoPro footage. I didn't test the power stage of the TX like you outlined so I'll do that as well. I also need to find something besides my tripod since it is aluminum.
For the following data I tested three different receivers:
Receiver #1 was a brand new receiver sitting atop a 6 foot tripod.
Receiver #2 is my oldest receiver and is installed in a quad strapped to the tripod about 5 feet up. Orientation is vertical with active element facing up and ground plane towards ground.
Receiver #3 is also installed in a quad but is horizontally installed and strung from back motor to back motor and is on top of the 6 foot tripod.
I'm providing only 5V to the flight controller on the quad installed receivers so noise from Vtx, etc, is not taken into consideration yet.
For #1 and #2 TX antenna is vertical and for #3 it is horizontal.
I walked (skated) 365m away with clear LOS to the receivers, activated logging, and slowly moved towards the quad always keeping proper antenna orientation.
Receiver #2 seems to be worse than the others but then again it was at 5 feet vs 6 feet but 10db is a lot of loss for a foot of height I think at only 365m.
Here's scatter plots for all three for RSSI vs Time:
Here's my average numbers while at range for each receiver:
Rec # RSSI RSNR RQly TRSSI TSNR TQly 1 85.5 db 27.9 db 100% 85.5 db 26.5 db 100% 2 96.5 db 13.3 db 98.5% 94.3 db 16.9 db 98.9% 3 82.3 db 25.9 db 98.3% 75.5 db 41.3 db 97.3%
These are rough averages as I walked way slower in the first test.
Are these values normal for 10mw at 365m? Noise floor was around -113db.
I feel like receiver #2 is clearly worse than #1 & #2.
FrSky at this distance was near 60db.
I have removed receiver #2 from the quad and will test it along with #1 as just a bare receiver.
Thanks for any help guys.
Raw data (XLSX): https://www.dropbox.com/s/qcbak0pz9l...Data.xlsx?dl=0
Since this thread is active and the issue is related. When I'm at 10mW and like 1.5-2 meters away, should I expect constant 300% LQ or is some variation expected? Because these values are noisy and go down to 270% very often. Same at 100mW and 6 meters and a wall between the receiver and transmitter, it keeps fluctuating.
Here's the error rate at 100mW power, couple of meters distance and a wall inbetween. (10mW at 2m unobstructed LOS it looks similar. There's errors on downlink, too.)
I suppose my receiver is broken, again? Transmitter power stage works fine per instructions in the KB article linked above.
Last edited by Glowtape; 26th March 2017 at 03:36 PM.
Ah, the X-axis are the channels, good to know.
That said, I'm having micro-failsafes on the field within 100m of LOS with the transmitter set to 25mW fixed or set to 100mW dynamic power. I can usually see the LQ drop a lot in the OSD when it's about to happen. I really need to get a DVR to demonstrate.