I see Steve's point, even though he did not just tell us the baud rate. I have been doing a lot of hunting around trying to find and understand the single tone waveforms used in MIL-STD-110. They don't often mention the actual baud rate because it appears that it is always 2400 baud. And maybe that is all the time?
One source that I found helpful, was a Norwegian doctoral dissertation on Adaptive Turbo Equalization which made the background information a bit more understandable since he worked through some of the examples. With 188-110B at the slowest 75 baud rate here is the calculation to confirm the symbol (baud) rate: fa = Rc x Q x Rf x fs fa = data rate @ 75 bps Rc = code rate @ 1/16 or .0625 Q = bit rate per symbol @ 1 Rf = frame pattern efficiency 1/2 or .5 fs = symbol (baud) rate 75 bps = .0625 x 1 x .5 x fs 75 = .03125 fs 75 /.03125 = fs fs = 2400 baud It seems hard to believe that this stuff can actually work, but until we get the rules changed for text baud rate to at least 2400, we won't be able to use this technology here in the U.S. on the HF bands as the lowest band we can operate 2400 baud on is 6 meters which allows 19600 baud. But it certainly can be tested on this band with hams that are close enough to try it out. Especially, noteworthy would be the AWGN on 6 meters with little QRM and QRN so you should be able to get a good feel for how well it works down into the noise since you could easily compare it to other modes. This is made even easier these days since we have more rigs that can work on 6 meters. Anyone doing that and who is willing to report on their comparisons? 73, Rick, KV9U Steve Hajducek wrote: > > In the U.S. ( correct me if I am wrong) which you are located, 300bps > for MIL-STD-188-110 is not legal for data on HF, nothing is due to > the symbol rate. > > Anyhow, what ever, who ever, where ever does using MIL-STD-188-110 > within the ARS, the standard 1800hz PSK carrier and 2400bps symbol > rate necessitates a 3Khz BW, so if you are not at least at 2.7Khz IF > BW, the results using the standard modem settings will be poor and the > higher the data rate the worst the results under perfect channel > conditions, add in QSB and the like and you get the picture. > > /s/ Steve, N2CKH >
