[digitalradio] Anecdotes about FCC inadvertent hostility toward ham radio digital modes?
I've recently read several digital ops repeatedly ominously state hams should never ask the FCC about digital issues because the FCCs answer might be extremely bad for the hobby, aka, never tickle a sleeping dragon. This sounds new to me, outside of the digital world, hams constantly pester the FCC with all kinds of imaginative questions and proposals. Digital is new to me (well, relatively new, for a 3rd gen ham for twenty years, anyway). I hear it repeated over and over from some digital hams. So that indicates there might be a bad story from ye olden days of ham digital regulation. All I'm asking for is something like back in '67 after a perfectly innocent question about maritime mobile RTTY onair identification, the horrible end result was radioFAX transmission was temporarily banned because of lack of CW ids. I'm only bugging you all, because I have no idea what to google for, once I have a couple keywords I can find the details of the event on my own. 73 de N9NFB
[digitalradio] Re: ROS - make it legal in USA
--- In digitalradio@yahoogroups.com, John B. Stephensen kd6...@... wrote: What ROS users should do is email their ARRL representative and have them petition the FCC to change the rules. One solution is to eliminate the emission designators and change the RTTY/data segment of each HF band to 0-500 Hz wide emissions and the phone/image of each HF band to 0-8 kHz wide emissions with 0-20 kHz above 29 MHz. Well, most hams inaccurately believe, as a simplification, that the rule is emission designators ending in A/B go at the bottom of the band, ending in E goes at the top of the band, and ending in D wiggle in between. However, the whole point of the ROS debate is that FCC 97.3(c) does exist, like it or not, and FCC 97.3(c) was way over complicated and is simply obsolete. The FCC is not going to wipe FCC 2.201 because hams don't like emissions designators. A simpler solution than yours, would be to wipe 97.3(c) and replace it with something along the lines of ordering our transmissions based on alphabetical order of the letter at the end of our emissions designators., and then toss something in about 97.101(a) implying that maximizing the amount of cooperation with as many as possible of the thousands of band plans would be defined as good engineering practice. Which would pretty much end up as the status quo, with the added feature of eliminating all future RF engineer lawyer-ing. 73 de Vince N9NFB
[digitalradio] Re: ROS, legal in USA?
--- In digitalradio@yahoogroups.com, Dave Ackrill dave.g0...@... wrote: Does anyone have a definition of real spread spectrum? As I hate to think what will happen when/if people with even less knowledge than I have of what 'real' spread spectrum is get the idea that RIO is something that it is actually not and start their inevitable campaign of 'It's illegal, it's immoral and it makes you fat', to use the words of the song... Dave (G0DJA) Well, as a G0 its perfectly acceptable that you don't know. The K's N's W's and A's have no such excuse. Lets check out 47CFR2.201 and see what type of signal ROS is. The first letter is modulation. Clearly its F Frequency modulated. I read the ROS PDF and its basically a 16FSK that has its carrier frequency modulated/wiggled in a peculiar pattern. The number is nature of signal(s) modulating the main carrier. Clearly its 2, A single channel containing quantized or digital information with the use of a modulating sub-carrier, excluding time-division multiplex. That sub-carrier is the 16FSK, which thankfully (?) isn't TDM data. The second letter is type of information to be transmitted. Well, obviously that is D for data. We're not sending E voice or A telegraph or whatever here. So, the overall FCC Emission designator would pretty obviously be F2D. Where can we run F2D? First, hit FCC 97.305(c) authorized emission types table. The FCC says SS only on 222 and up. I have no idea what inspires people to publically claim you can only run SS on 432 and up, as 97.305(c) explicitly permits it on 222 and up. For another example, on 30M we can do RTTY or DATA. How does DATA or RTTY or SS or PULSE relate to emissions designators? The FCC helpfully defines that in 97.3(c) To qualify as SS all it needs per 97.3(c)(8) is Spread-spectrum emissions using bandwidth-expansion modulation emissions having designators with A, C, D, F, G, H, J or R as the first symbol; X as the second symbol; X as the third symbol. F2D doesn't seem to match the def of SS. To qualify as DATA all it needs per 97.3(c)(2) is Telemetry, telecommand and computer communications emissions having (i) designators with A, C, D, F, G, H, J or R as the first symbol, 1 as the second symbol, and D as the third symbol; (ii) emission J2D; and (iii) emissions A1C, F1C, F2C, J2C, and J3C having an occupied bandwidth of 500 Hz or less when transmitted on an amateur service frequency below 30 MHz. Only a digital code of a type specifically authorized in this part may be transmitted. F2D doesn't seem to match the def of DATA. Looks like USA folks can't transmit ROS at all, on any band. Ooops. Will people fooling around with ROS get dragged to court? Probably not. See 97.305(b) A station may transmit a test emission on any frequency authorized to the control operator for brief periods for experimental purposes, except that ... (essentially no SS or pulse where not otherwise permitted). So, fooling around for testing and experimentation of a new mode is well within the law by this exception. Running a contest, a regular schedule, a formal net, DXing, QSL card collecting, county hunting, or extensive ragchewing would be strictly verboten under 97.305(b). The key is doing it in a documented manner as an experiment, like as a research experiment or an article for QEX. Realize that big brother can deprive you of your life and liberty at any time for any reason, its not as if a rule prevents that, it just claims Big Bro won't do it, and politicians never lie... In summary, the problem seems to be FM modulating the carrier of the 16FSK. 73 de Vince N9NFB
[digitalradio] Re: Using CTSS on a digipeater?
--- In digitalradio@yahoogroups.com, Terry Breitenfeldt tabreitenfe...@... wrote: Let me thow out a couple more issues about this problem: 1) The Digi would be located on a hill over 10,000ft high, in an area prone to immense RF inference. Because of its height and the nature of digital signals, I'm concerned that a KPC+ would be overwhelmed hearing multiple signals from hundreds of miles away that might make the TNC unavailable, just when it needs to be available exclusively for ECOM. Even if a closed group were technologically possible, even inside a closed group you can still have massive hidden transmitter problems causing thruput problems. So if ham X 50 miles N can't hear the transmissions of ham Y 50 miles south, then the LAN will break down if ham X and ham Y both try to access the same digi. All the stations on the network will need hundreds of miles of range not just the digipeater. You may want to look at what the folks in WI and MI and MN (and probably many other locations) have done. Now if you installed multiple directional antennas and radios pointing to distinct metro areas on distinct frequencies, that culd work quite well. So antenna 1 pointing to metro area #1 where everyone in metro area #1 can hear each other while using off the shelf mobiles could work. Use nodes instead of digis and link them together. 73 de Vince N9NFB
[digitalradio] Re: Using CTSS on a digipeater?
--- In digitalradio@yahoogroups.com, Terry Breitenfeldt tabreitenfe...@... wrote: If I wanted to setup a closed Digipreater on 145.09 Mhz on a high mountain peak, so that I could limit activity to only ECOM traffic, would the use of a CTSS tone decode be a viable option? Would a CTSS tone interfere with Packet operations? A) What is there about ECOM that would inherently make only ECOM communications use CTCSS? Most of the plain ole analog voice repeaters around here use CTCSS on the input. Perhaps in some areas only ECOM radios have CTCSS tones, but not here nor most areas. B) What is there to gain by making sure that the ECOM infrastructure is only tested by real genuine ECOM traffic vs continuous testing by random hams? Far better to find out the digi is desensed or the amp is fried under non-ECOM conditions. C) Also since somewhere around 99% of actual emergency communications is handled by casual operators whom rise to the occasion, I'm not sure most emergency comms would be able to use a confusingly configured closed digipeater. So, moral and ethical issues aside, what are the technical problems: 1) SLOW CTCSS on some radios. Neither you nor anyone else using the digipeater can use a radio that is slow, or at least you'll have to slow the TXDELAY down to the speed of the slowest CTCSS decoder on the channel... Assuming everyone configures correctly, it'll merely be slow, but more likely they'll have massive retransmit problems. 2) Hidden Xmitter problems mean this simply cannot work. If either the users or the digi filter out non-CTCSS traffic to only hear closed traffic, then they'll transmit on top of the more legitimate open traffic because the TNCs will think the frequency is open. The end result is no thruput for either the closed users or open users, just alot of interference. 73 de Vince N9NFB EN53ua
[digitalradio] You Have Mail Re: How Can We Push HF Emcomm Messages to the Field?
--- In digitalradio@yahoogroups.com, Howard Z. [EMAIL PROTECTED] wrote: 2m/70cm D-star radios can communicate with each other without a repeater. These radios can send audio and slow speed data Another option is 1200 baud packet. I have not played with this very I played with 1200 baud packet ALOT in the early 90s in SE wisconsin. Sounds like you want an external TNC like a KPC-3 http://www.kantronics.com/products/kpc3.html About the size of a paperback book, cheaper than a d-star module, draws 30 mA (thats thirty mA, not three hundred mA). Folks connect to n9nfb-1 to talk to the internal mailbox (or connect via the built in ka-node thru the network if out of direct simplex range). When they leave you an email the far right LED mail illuminates. No need leave the laptop connected and running a certain program 24x7, perfectly OK to do something else until you see the little mail indicator on the TNC. Good luck finding a laptop that draws less than 30 mA while running a soundcard modem program. 73 de Vince N9NFB
