Author Archive
Run ROS, Go Directly To Jail (Do Not Collect QSL Card)????
February 25th, 2010 | 
Author: There's been a ruckus over the new ROS digital mode going on in radio amateur blogademia and on radio ramateur reflectors. (Rut-ro!) Apparently ARRL has advised someone that ROS is spread spectrum and therefore is illegal below 222 Mhz in the US. The manual for ROS describes it as "a digital communications software based on a FSK modulation of 144 tones".
I haven't been able to find any ARRL article or official statement on it, however this supposed communication from ARRL was posted on the digitalradio reflector:
"From: Henderson, Dan N1NDSubject: RE: Spread SpectrumTo: [deleted for privacy]Date: Tuesday, February 23, 2010, 7:13 AMHi Fred:I ran this by our technical experts. They concur that ROS is a spread spectrum mode and as such is not allowed by the FCC on bands below 222 MHz. Remember that approved emissions vary from IARU Region at times as well as between countries. So while the IARU Band Plan for Region 2 would allow it, SS is not permitted on the HF bands by the FCC/Thanks and 73Dan Henderson, N1NDRegulatory Information ManagerARRL, the national association for Amateur Radio™ "
But is ROS really spread spectrum? Just what is spread spectrum? Let's ask our friend, Part 97.
§97.3(c)(8) SS. 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
That's incredibly vague, but basically spread spectrum is taking a signal and spreading out its bandwidth in order to improve interference immunity and/or obscure the intelligence. There are two primary methods, direct sequence and frequency hopping. With direct sequence the intelligence is mixed with a pseudo-random bit sequence at transmit and demodulated in the receiver with the same pseudo-random sequence. With frequency hopping, the signal simply rapidly hops around a predetermined band. Apparently it's assumed that ROS is frequency hopping spread spectrum.
One key difference I see between ROS and commonly accepted frequency hopping spread spectrum systems is that there's no modulation on the ROS carriers. The intelligence in a frequency hopping spread spectrum system is not determined by the frequency of the carrier at any given moment, it's determined by the modulation on the carrier itself. (OK, if you're using QAM modulation there is a frequency modulation component, but that's totally independent of the frequency hopping.) In ROS the intelligence is carried by the frequency of the carrier in time. The only difference between ROS and MKSK, besides the symbol rate and bandwidth is that ROS has only one tone on at a time and MFSK can have multiple. But let's assume for a moment that ROS is frequency hopping spread spectrum. RTTY also frequency hops. It hops between two frequencies. This hopping does expand the bandwidth, so therefore using this same interpretation that has been applied to ROS, RTTY is also spread spectrum and therefore it is illegal below 222 Mhz.
I hope ARRL realizes that ROS is frequency shift keying and not spread spectrum and reverses this initial finding. We need to have common sense prevail and not turn this into another unnecessary rule interpretation quagmire like the whole emcomm and employers issue has become. If ROS stays within the bandwidth allowed for other HF digital signals, what does it matter? Let's use it and move on.
February 23rd: U.S. Amateur Radio Liberation Day
On February 23rd 2007, amateur radio in the U.S. was liberated from the tyranny of a minority of radio amateurs. They said amateur radio would be destroyed. The foundations of amateur radio were being dismantled, eliminating all that was good and wholesome, ruining decades of innovation and service. Hiram would be turning over in his grave. Cats would be sleeping with dogs. Rupaul would be sleeping with women. The bands would be silent as a long cherished traditional would be outlawed. The CBers would be dancing in the streets and invading our bands, polluting and pillaging our precious frequencies. Old men would have to talk about something other than the early dinner specials at Dennys. It was a grim and apocalyptic picture they painted in those days leading up to the great event.So celebrate this February 23rd, U.S. Amateur Radio Liberation Day, a most joyous amateur radio holiday, by operating CW....not because someone made you take a test, but because you enjoy it.
QSY? QSY. QSY? QSY. QSY? QSY!!!!
Word has been going around in radio artisan blogademia that the lets-move-the-QRP-calling-frequency movement is afoot, yet again, apparently on QRP-L. I checked the QRP-L reflector and didn't see anything about it. Hmmm. Must be on that other QRP-L....let me check. What? They want me to subscribe in order to read the archive? No, I don't think so.
I don't know how much more can be said about moving the QRP calling frequency. RTTY interference. Check. Rock bound rigs. Check. Region 1 versus Region 2 bandplans. Check. 7040 on a gazillion website lists and stone tablets. Check.
What are we waiting for? A QRP elder to give their blessing? Hiram to appear and make known his wishes? A Rockmite retrofit kit?
Doohhhhh!
Apparently the Utility DXers Forum (UDXF) reported that LORAN had been saved by radio amateurs, a story first reported here at The K3NG Report. The Milcom Monitoring Post blog attempts to set the record straight.
Yes, the story was a spoof. Radio amateurs unfortunately are not saving LORAN. LORAN is being deactivated so that we'll be defenseless against mutant alien ants that are awaiting the network of GPS satellites to be turned into chunks of space garbage after the next X class flare. I've been decoding the shortwave numbers stations for some time and I know a bit about their plans. Oooops, I said too much already.
Wooden Tower Plans
The Pacific Northwest Region Forest Service has this neat collection of wooden fire tower plans available on their website. The various plans are from 1936 to 1965 and are provided for historic reference. While as the website mentions they do not meet current building codes, I've often dreamed about building one of these and using it for a station tower and perhaps having a hamshack up in the tower cab. Maybe someday when I have a ten acre wooded lot and a lot of time on my hands...and lots of life insurance.... :-)
Thanks the Pacific Northwest Region Forest Service for preserving these documents and posting them online.
Radio Amateur Volunteers to Save LORAN
Earlier this week President Obama announced that the aging LORAN navigation system would be deactivated, saving the U.S. $190 million over the next five years. Radio amateurs were vocal in their opposition to the deactivation, claiming that the antiquated system was a good backup if GPS failed.This morning President Obama reversed the decision, calling upon amateur radio volunteers to assist in the situation. "Today we ask radio amateurs, also known as 'hams' to help save the LORAN system. Hams came to the aid of their country in World War II, providing over 30,000 radio operators. Today we are asking for 500 amateur radio volunteers to run the system over the next five years."
Details were sketchy at the press conference, however a press release later in the day stated that volunteers would receive only room and board in LORAN station facilities, and the program would save a half billion dollars over the next 20 years. FCC Chairman Julius Genachowski applauded the decision noting that radio hams are known for their technical astuteness with antiquated systems and World War II technology, and were likely the best qualified to keep the obsolete system running for decades to come.
Senate Republicans who several days ago were critical of the administration for making a "foolish decision" to deactivate LORAN which would "compromise national security" released a statement in response to today's reversal calling the decision to keep LORAN running "another example of reckless spending that will increase the deficit and threaten freedom", vowing to block all attempts to keep the system running.
Details were sketchy at the press conference, however a press release later in the day stated that volunteers would receive only room and board in LORAN station facilities, and the program would save a half billion dollars over the next 20 years. FCC Chairman Julius Genachowski applauded the decision noting that radio hams are known for their technical astuteness with antiquated systems and World War II technology, and were likely the best qualified to keep the obsolete system running for decades to come.
Senate Republicans who several days ago were critical of the administration for making a "foolish decision" to deactivate LORAN which would "compromise national security" released a statement in response to today's reversal calling the decision to keep LORAN running "another example of reckless spending that will increase the deficit and threaten freedom", vowing to block all attempts to keep the system running.
ARRL officials were excited over the decision, announcing that all hams who volunteered at the LORAN stations could append a /L to their callsigns, in celebration of the saving of the LORAN network.
Reaction to the program to save LORAN on amateur radio forums and on the air was mixed with many questioning whether CW proficiency would be required of volunteers in order to insure that only technically qualified individuals would be operating the LORAN transmitters.
Walmart Closeout Rechargeable Batteries
A few days ago I found these rechargeable sealed lead acid lantern batteries from Remington for $5 each (normally $9.47) in the sporting goods section at Wally World.
They're each 6V 4.6 Ah, and (obviously) make 12V if used in series. They should make good backpacking batteries. I didn't really need anymore batteries, but it seemed like a good deal. I'm not sure if all Walmarts have these on closeout, but you may want to check your local store if you're needing some rechargeables for outdoor expeditions.
They're each 6V 4.6 Ah, and (obviously) make 12V if used in series. They should make good backpacking batteries. I didn't really need anymore batteries, but it seemed like a good deal. I'm not sure if all Walmarts have these on closeout, but you may want to check your local store if you're needing some rechargeables for outdoor expeditions.
