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shortwavesurfer2009

I haven't read the regulations behind this, but this might work over CB radio on 11 meters as well. A lot of CB uses AM instead of single sideband, which, if you can get it to work, might actually be able to transmit data faster, since you'd have more frequency space to work with.

However, that may not work because AM might just mirror what's on one side band with what's on the other side band instead of being able to transmit more data.

Liberty Farmer 5mo ago 💬 2

Are there data allotments on cb?

I believe there is no data allowed, unsure.

However, you can now use up to 2.8khz bandwidth on ssb data. A recent change. This will allow much much higher speeds on things like HAMSTR on 10M or 6M.

Currently, I test on the 20, 40, 80m bands at 300 and 600 baud. In theory you can now push to higher limits, the reality of physics and error correction limitations come on to play at those.

I will be opening up HAMSTR to vara hf and VHF modems, and fldigi and the full suite of data modes soon. Fl digi in particular will allow for some pretty fast data transfer rates, especially on fm/VHF. Vara too.

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Discussion

shortwavesurfer2009 5mo ago

I'm not sure if there are data allotments on CV or not.

My best guess is probably not, which would make this impossible, unfortunately.

Liberty Farmer 5mo ago 💬 2

Im 99% there isn't. AM data is for sure a thing and allowed however, but it would need to be a customodulation scheme I think, I don't know of any off the top of my head. You also would run into the same carrier width restrictions, so in reality, you would have half as much signal I think.

shortwavesurfer2009 5mo ago

Well, AM is wider bandwidth than signal sideband because AM is basically a double sideband, but I do believe that what's on one is mirrored on the other, so you'd be losing signal strength and not getting any more data through, which would be unfortunate.

With single sideband, all of your power is going into a smaller bandwidth which makes it travel further distance.

Liberty Farmer 5mo ago 💬 1

Correct. What I mean is that currently, the FCC limit is 2.8khz for data modes. So on am, you would need a 1.4khz signal on each side, minus the carrier signal. So it doesn't really help. On VHF frequencies you can just use fm modes at a much higher rate. With the tradeoff of less range of course.

shortwavesurfer2009 5mo ago

Oh, okay. I see what you mean now.