Re: VARA vs. Pactor-III Speed Comparison Plots
It certainly was a time consuming process. It's interesting to note that short-term changes in propagation had less of an effect on modem speed than I expected. Speeds usually varied by 20 percent or less in the relativity short period of time it took to extract an average from multiple test runs.
Jose did mention the changes he made to the protocol and I suspect it would have had a slight impact on the results. To your other question: no, I didn't measure variation in power consumption.
I'm not aware of any test data that includes Pactor-4 and VARA, but I suspect that would be something those in emergency communications would be interested in.
Obviously, the proper way to compare HF modems would be under the controlled environment of an HF path simulator, but I think on-air testing can reveal certain throughput characteristics that may not show up on an artificial path. I think it all depends on how complex the real path is and what the path model limitations are.
6/15/2018 10:37 AM, Graham wrote: