12-06-2023, 08:58 AM
Here is a data log conundrum. As the pilot I experienced no radio signal problem.
This plot of data logging from a flight this morning shows several unexplained drops in receiver signal to noise (RSNR). The plane was a Flash 1m 3d profile with a 3S lipo, controlled by a RM Tx16 tx with elrs internal module and Edgetx firmware, and a matek R24P rx. I set dynamic power on, which means a rx algorithm decides when/whether there is a radio signal issue and increases tx power whenever needed.
Each data series is modified so that all 6 series can be clearly seen in 1 plot.
The RXBat+20 shows that the rx voltage was fine at 5v throughout - none of the approx 600 measurements at 0.5 sec intervals deviated from 4.9 or 5v.
The throttle setting (THR) goes from -20 (no throttle) to +20 (full throttle).
From the THR you can locate the 2 blenders in this flight: at the start of a blender there is a vertical climb requiring full throttle, at the top I cut the THR to zero to commence the vertical plunge and spin. For the first blender the THR was cut at 50 sec, the second at 225 sec.
The RSSI (signal strength) and the RQly (rx quality aka VFR) were within normal limits throughout the flight - not a single measurement was abnormal.
However the TPWR (transmitter power) which was at 10 mw throughout had 4 episodes of an increase to 25 mw. Each tx power increase was associated (maybe triggered) by a significant decline in RSNR (receiver signal to noise ratio), from 10 or 11 down to 4 db. A RSNR of 4 means the signal is still much stronger than the noise, and RSSI and RQly were not affected, but what caused the fall in RSNR?
The increase in TPWR means the rx algorithm thought there was a signal problem. Two of the episodes of TPWR increase were associated with a blender, the other 2 also seem linked to high THR.
Interference from the 5G tower or a nearby factory would not be in time with my blenders, so cannot account for the episodes of reduced RSNR.
Maybe the increased power in the vertical climb for the blender means interference from the esc reduces the RSNR, and that triggers the tx power increase? But my esc is not mounted very near by the rx or antenna.
This plot of data logging from a flight this morning shows several unexplained drops in receiver signal to noise (RSNR). The plane was a Flash 1m 3d profile with a 3S lipo, controlled by a RM Tx16 tx with elrs internal module and Edgetx firmware, and a matek R24P rx. I set dynamic power on, which means a rx algorithm decides when/whether there is a radio signal issue and increases tx power whenever needed.
Each data series is modified so that all 6 series can be clearly seen in 1 plot.
The RXBat+20 shows that the rx voltage was fine at 5v throughout - none of the approx 600 measurements at 0.5 sec intervals deviated from 4.9 or 5v.
The throttle setting (THR) goes from -20 (no throttle) to +20 (full throttle).
From the THR you can locate the 2 blenders in this flight: at the start of a blender there is a vertical climb requiring full throttle, at the top I cut the THR to zero to commence the vertical plunge and spin. For the first blender the THR was cut at 50 sec, the second at 225 sec.
The RSSI (signal strength) and the RQly (rx quality aka VFR) were within normal limits throughout the flight - not a single measurement was abnormal.
However the TPWR (transmitter power) which was at 10 mw throughout had 4 episodes of an increase to 25 mw. Each tx power increase was associated (maybe triggered) by a significant decline in RSNR (receiver signal to noise ratio), from 10 or 11 down to 4 db. A RSNR of 4 means the signal is still much stronger than the noise, and RSSI and RQly were not affected, but what caused the fall in RSNR?
The increase in TPWR means the rx algorithm thought there was a signal problem. Two of the episodes of TPWR increase were associated with a blender, the other 2 also seem linked to high THR.
Interference from the 5G tower or a nearby factory would not be in time with my blenders, so cannot account for the episodes of reduced RSNR.
Maybe the increased power in the vertical climb for the blender means interference from the esc reduces the RSNR, and that triggers the tx power increase? But my esc is not mounted very near by the rx or antenna.