Test items:
1. CORONA (2X2 2.4G + FF9 2.4G)
2. JR DSX7 (SPEKTRUM)
3. ASSAN
4. FUTABA FF10 (FASST)
Test meter: Agilent E4404B Series Specturm Analyzer and Agilent N5182A Vector Signal Generator.
The analysis range is 9K~6.7G. The yellow line show on monitor is ASSAN, The blue one is CORONA and DX7. The red one is Futaba FF10.
The single range of Vector Signal Generator is 100K~6G.
The blue line is from Radio and the yellow one is from signal generator.
2.4G system is not easy to be interfered. If the noise continuous, the frequency will be changed after restart the radio. But during using, the frequency doesn¡¦t change.
Data analysis:
Radio System: CORONA (9X II 2.4G + FF9 2.4G)
Features: Using 2 fix narrowband single for hopping.
Technique: 2.4G + Frequency Hopping.
Power: normal
FH function: 2~3 frequency (FDMA)
Anti-interference: If 2 channels be interference in same time, it will be locked.
Frequency & channel using: 2~3 channel in ~500Mhz.
SPEKTRUM JR DSX
Features: Auto scan free frequency, than select 3 channels for communication.
Technique: 2.4G + Frequency Hopping
Power: normal.
FH function: Auto sane, 3 channels (FDMA)
Anti-interference: If 2 channels be interference in same time, it will be locked.
Frequency & channel using: 2~3 channel in ~300Mhz.
ASSAN
Features: Fix frequency narrowband single
Technique: 2.4G
Power: normal
FH function: no
Anti-interference: Probably will be interference if the noise large than single, because it use only one frequency.
Futaba FF10 (FASST)
Features: Use N channel included almost 2.4G frequency.
Technique: 2.4G + Frequency Hopping Spread Spectrum, FHSS.
Power: normal
Anti-interference: If noise is broadband, will be lock.
Frequency & channel using: N channel in ~800Mhz.
Conclusion:
1. Different brand are un-compatible.
2. If be interference, all servo will be locked. No like PPM, servo will shake.
3. If there is any 2.4G AP station very close, probably will interference because one AP station needs 16 MHz band width.
4. FF10 probably will interference other brand radio.
5. We don¡¦t know do those radio with TDMA function. We only can identity FDMA tech.
6. Seems, no radio us DDS (Direct Sequence Spread Spectrum) tech to do CDMA commutation.
7. Same brand radio work in same time, almost impossible to be interference. But different brand radios maybe will interference others