Erhard,
I do not have any real lab equipment to measure the output of the transmitters. I tried using an Immersion RC Power Meter, but since the transmitter signal is hopping and has a low average power, I could only get vague results.
However, I did get repeatable results using the XPS XDP device in conjunction with the XPS RSSI application.
I have repeated this test with my XPS JR and XPS Futaba transmitter modules and the results were pretty much the same. Using the XDP device:
Bring up the Tx RSSI tester application and place the working transmitter 3 feet away. I just did this test with my Taranis and XPS-J1 transmitter module. At 3 feet I saw signal strength numbers in the area of -40dBm.
Then I moved the transmitter to a spot about 20 feet away and the new RSSI numbers were about -61dBm.
Then, still about twenty feet away, I placed the transmitter in my refrigerator (a big metal box) and the RSSI went down to -77dBm.
Since both of my transmitter modules produced similar results, I decided that they were both working properly.
The RSSI numbers can vary quite a bit based on the relative location of the transmitter and the XDP device. I wasn't so concerned about the absolute numbers. The test can, however, give a good comparative results to see if one transmitter module is performing differently from another.
Paul
p.s. With the RSSI application running, you can press the low power button (range check mode) on the back of the transmitter module and see the overall signal strength go down.
I do not have any real lab equipment to measure the output of the transmitters. I tried using an Immersion RC Power Meter, but since the transmitter signal is hopping and has a low average power, I could only get vague results.
However, I did get repeatable results using the XPS XDP device in conjunction with the XPS RSSI application.
I have repeated this test with my XPS JR and XPS Futaba transmitter modules and the results were pretty much the same. Using the XDP device:
Bring up the Tx RSSI tester application and place the working transmitter 3 feet away. I just did this test with my Taranis and XPS-J1 transmitter module. At 3 feet I saw signal strength numbers in the area of -40dBm.
Then I moved the transmitter to a spot about 20 feet away and the new RSSI numbers were about -61dBm.
Then, still about twenty feet away, I placed the transmitter in my refrigerator (a big metal box) and the RSSI went down to -77dBm.
Since both of my transmitter modules produced similar results, I decided that they were both working properly.
The RSSI numbers can vary quite a bit based on the relative location of the transmitter and the XDP device. I wasn't so concerned about the absolute numbers. The test can, however, give a good comparative results to see if one transmitter module is performing differently from another.
Paul
p.s. With the RSSI application running, you can press the low power button (range check mode) on the back of the transmitter module and see the overall signal strength go down.