Digital Solves All Your Problems? OK, I admit, that’s pure click-bait. In this episode I talk with Bruce Perens K6BP. Some of you may recognize that name, and maybe not have even known Bruce is a ham. Out there in the real world, Bruce is known for being one of the founders of the Open Source Software movement, and he remains an evangelist for the idea. Here in Ham Radio, he’s turned that focus to things like CODEC2, FreeDV, and the HT of the Future (put some mental reverb on that as you read it).
What we’re talking about begins with the ARRL’s FCC petition to update our rules regarding digital modes to get rid of the reference to Symbol Rate, and replace it with a simple 2.8 kHz bandwidth limit (on HF) into which you may stuff anything that’s legal… BUT, they retain the cw/data – Phone/Image distinction. I just spent a few quality minutes on Wikipedia trying (again) to understand symbol rate, and I don’t get it. But I do get bandwidth.
Our discussion progresses to more on CODEC2 (a free, open-source CODEC for high-quality, low bit-rate voice transmission), FreeDV (a free, open-source program for using CODEC2 on digital voice) and that HT (HT HT HT).
But it’s that 2.8 kHz bandwidth idea that’s got a lot of ham’s undies in a knot. The worry, as I understand it, is that with an “anything goes” 2.8 kHz digital policy, digital will proliferate across the bands, causing interference to analog modes (SSB, CW). And the analog ops won’t be able to tap the digital ops on their RF shoulder and say sri, OM, QRM, pse QSY, tnx. WinLink2000, a fairly wideband and often automated digital mail system, is frequently the focus of their displeasure, as it can tromp on a cw QSO without recognizing what it’s doing (if I understand the argument correctly, and I don’t claim that this is either a complete and correct analysis of the issue).
In the program, Bruce and I recognize the potential problem. We might not think it’s likely to be as serious as some hams think it is, and we don’t have a solution, other than to note that QRM is a fact of life. But it is something worth discussing, and I’d like to have that discussion soon on another episode of HamRadioNow. I’ve got a few suggestions on guests to talk to about it, but I’m open to more (be quick).
We think the ARRL is taking a baby step with this proposal, in that it retains what we think is an artificial distinction between bits that make text, and bits that make image and voice. But last time the ARRL tried anything like this, about 10 years ago with their “Regulation by Bandwidth” proposal (a far more sweeping plan that would have divided the bands into segments that permitted stuffing whatever fit into 200 Hz, 500 Hz, and 3 kHz bandwidths), a large part of the membership got very unhappy. They still are.
So expect the topic to come up in the near future, and periodically for a while, because this won’t have a quick fix. But I don’t think it’s a good idea to hold back progress on future modes because they may cause some trouble with our current modes.
73, Gary KN4AQ