If everyone did switch over to HF digital equipment and abandoned their analog mode equipment, it is very likely that this would drastically reduce our overall ability to communicate.
This is particularly true of voice communications. I don't think the science supports the ability to have digital weak signals working as well, much less better than, analog weak signals, when you need the high throughput rate of voice. That is why we can do slow digital modes, e.g., text, at relatively weak signals (< -17 db S/N with PSK10) but voice modes require tremendously better signals (~ + 10 db S/N). The difference is the need for the drastically higher rates of data throughput for voice. We only have to look at D-Star and APCO25 equipment. These modes can not compete with analog signals under difficult conditions. Not to mention the difficulty in finding the "sweet spot" in real time when you are operating portable. Some have suggested that the digital technology can only get better. Perhaps it can. We will have to see if there are some breakthroughs in the future. Otherwise, my understanding is that you generally either have to increase power or increase bandwidth in order to make digital modes more robust and/or have higher throughput. Since we will likely be limited to 3.5 KHz bandwidth on most HF frequencies in the near future here in the U.S., this will restrict further experimentation on HF. A few are claiming wonderful possibilities for high baud rates on HF if only we could run those high baud rates. The truth is that we can do this right now on VHF and up albeit under much easier (but shorter distance) propagation conditions. But we typically need much wider bandwidths than with SSB, which still seems to be the best overall voice mode for a wide variety of signal conditions in terms of weak signal capabilities, ionospheric conditions e.g., selective fading, etc. My point being that higher HF baud rates may be of limited value compared to giving up the ability to use wider bandwidths. Much of the "new" technologies are beginning to sound a lot like when we went through the promotion of ACSB (Amplitude Compandered Side Band) several decades back. For those who were around then, remember how this highly touted technology was going to revolutionize voice communications. But it proved to be marginally effective considering all the added complexity. The main advantage was for non technical operators operating on a "channel," and even then it never was all that successful for commercial use either. Another example is when we pushed for the ability to transmit 110 baud ASCII on HF. This was to be a really big paradigm shift and revolutionize HF digital. Yet it proved to be far less effective than RTTY and after a short time of experimentation, was abandoned. How many of us use the ASCII mode that many of the multi-mode digital interface boxes had as a selection? 73, Rick, KV9U >Think about what your saying here. Amateur radio is going to become a >step-child of BPL, looking for notches in the BPL signal to operate >in. In addtion, what was recommended was trashing all current radios >and moving to wide band capable ones. Are you ready to put all your >analog radios in storage, and tell every other ham in the US that they >will have to do the same, and fork over multi-thousands of dollars for >new, more capable radios all because we are going total digital? > > > Need a Digital mode QSO? Connect to Telnet://cluster.dynalias.org Other areas of interest: The MixW Reflector : http://groups.yahoo.com/group/themixwgroup/ DigiPol: http://groups.yahoo.com/group/Digipol (band plan policy discussion) Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/digitalradio/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/digitalradio/join (Yahoo! ID required) <*> To change settings via email: mailto:[EMAIL PROTECTED] mailto:[EMAIL PROTECTED] <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
