08-24-2026, 11:57 AM
Interesting result:
I performed a range test with an XPS transmitter module in a Taranis and a Nano receiver. I used the XPS Telemetry Station to record the receiver’s RSSI. Then I repeated the test with an ELRS RadioMaster TX15 transmitter and ER4 receiver.
In both tests I placed the receiver, servo and battery 125 feet away, and four feet off of the ground on a stool. I oriented the receiver's antenna vertically. I placed the transmitter four feet high with its antenna also oriented vertically. In both tests I configured the radio transmit power to 25mw. I turned on my "servo test" model which runs channel one end-to-end once per second. In both tests the receiver and servo ran reliably under these conditions (not surprising).
The results for both the XPS Nano and ELRS systems were pretty much the same, with each showing an average RSSI of about -73dBm.
I repeated the test using an XPS RFU with its -109 dBm sensitivity and an X10+v2. In the test, the RSSI with the RFU was about -65 dBm. Better than the ELRS setup.
The ELRS system provides link quality and signal to noise ratio telemetry data as well. The link quality at 25mw never went below 99% and the SNR never went below 9dBm. I repeated the ELRS test at 10mw transmit power and the average RSSI was down to about -77dBm, the lowest LQ was 95%, and the lowest SNR was 6dBm.
The ELRS documentation puts the theoretical ELRS receiver sensitivity at -112 dBm when using a packet rate of 100Hz. I think the ELRS (CRSF) data rate is 400Kbps. The RFU’s data rate (Xtreme) is 250Kbps.
I performed a range test with an XPS transmitter module in a Taranis and a Nano receiver. I used the XPS Telemetry Station to record the receiver’s RSSI. Then I repeated the test with an ELRS RadioMaster TX15 transmitter and ER4 receiver.
In both tests I placed the receiver, servo and battery 125 feet away, and four feet off of the ground on a stool. I oriented the receiver's antenna vertically. I placed the transmitter four feet high with its antenna also oriented vertically. In both tests I configured the radio transmit power to 25mw. I turned on my "servo test" model which runs channel one end-to-end once per second. In both tests the receiver and servo ran reliably under these conditions (not surprising).
The results for both the XPS Nano and ELRS systems were pretty much the same, with each showing an average RSSI of about -73dBm.
I repeated the test using an XPS RFU with its -109 dBm sensitivity and an X10+v2. In the test, the RSSI with the RFU was about -65 dBm. Better than the ELRS setup.
The ELRS system provides link quality and signal to noise ratio telemetry data as well. The link quality at 25mw never went below 99% and the SNR never went below 9dBm. I repeated the ELRS test at 10mw transmit power and the average RSSI was down to about -77dBm, the lowest LQ was 95%, and the lowest SNR was 6dBm.
The ELRS documentation puts the theoretical ELRS receiver sensitivity at -112 dBm when using a packet rate of 100Hz. I think the ELRS (CRSF) data rate is 400Kbps. The RFU’s data rate (Xtreme) is 250Kbps.