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> In what legal jurisdiction can you use a 10 MHz bandwidth channel under <30 MHz (where you actually get ionospheric bounce (sometimes))? I never implied you
by ac29 7y ago
> In what legal jurisdiction can you use a 10 MHz bandwidth channel under <30 MHz (where you actually get ionospheric bounce (sometimes))?
I never implied you could? Its certainly possible in VHF/UHF, though (for licencees).
> And even worse than the answer to that (nowhere) is that in the USA the data rate limit is actually in terms of symbol rate, not bandwidth used
Sure, but those limits only apply for HF and longer-wavelength frequencies. You're welcome to do 256QAM in the microwave range, for example.
- superkuh 7y ago> Its certainly possible in VHF/UHF, though (for licencees). >You're welcome to do 256QAM in the microwave range, for example. Which gets back to line of sight propagation (tropo is not common) and everything I said in my first post. I've tried the home to car omnidirectional link thing on 902-928 MHz. All that matters is line of sight. I tried a 25w bidirectional amp (ham general license) and that didn't help. I tried bringing the ubiquiti transceivers w/broadband hamnet firmware all the way down to QPSK modulation and the narrowest channel I could. I even tried using narrowband 56k telemetry dongles. I customed designed and built my own microstrip based filters for the front ends. The only thing that really helps, and it's not enough, is height above terrain. When I go park my car on the hills outside of town megabits are possible. But the slightest hill or valley losing LOS kills it.