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
The final ARRL petition didn't change the rules in 97.221 for automatic
stations:
APPENDIX A – AMENDED March 22, 2007
PROPOSED RULE CHANGES
Part 97 of Chapter I of Title 47 of the Code of Federal Regulation is proposed
to be amended as follows:
Section 97.3(a)(8) is amended to read as
The 300 baud limit applies only to the HF RTTY/data segments. In the
phone/image segments below 29 MHz there s no baud rate limit but the bandwidth
is limited by the following parts of 97.307(f).
(1) No angle-modulated emission may have a modulation index greater
than 1 at the highest
Pactor was FSK with a 100% duty cycle (or peak to average power ratio - PAPR),
but Pactor-III is OFDM which has a PAPR similar to SSB and much less than SSB
with RF clipping so I don't see how its any worse than digital voice or SSTV.
Were the two stations in the automated segments fighting or
Commercial and military SS systems also use FSK so that not likely alleviate
the problem. The pseudorandom movement of the center frequency is the issue.
Since the object is to prevent intersymbol interference due to multipath
spread, one way around the legal issue is to transmit even symbols
Any petition should reduce regulation rather than increase its complexity by
continually adding loopholes. ROS is not the only mode that is currently
illegal -- there are single carrier PSK digital modes that U.S. amateurs can't
use because of the baud rate limit. U.S. regulations should be
The FCC only requires that a technical description be published:
Sec. 97.309 RTTY and data emission codes.
(a) Where authorized by Sec. Sec. 97.305(c) and 97.307(f) of the
part, an amateur station may transmit a RTTY or data emission using the
following specified digital codes:
(1)
Convolutional coding and Viterbi decoding may increase the occupied bandwidth
but they also decrease the amount of power required to communicate. In some
cases, like trellis-coded modulation, the bandwidth stays the same even though
the power required decreases by a factor of 2-4. Spread
These modes use interleaving and randomize data values by exclusive-ORing with
a pseudorandom binary sequence. The methods are used in most commerial products
and the FCC and NSA know how to monitor the signals.
The FCCs problem is that the military uses FHSS and DSSS to hide the existance
To: digitalradio@yahoogroups.com
Sent: Wednesday, February 24, 2010 03:37 UTC
Subject: Re: [digitalradio] Consensus? Is ROS Legal in US?`
On 02/23/2010 10:22 PM, John B. Stephensen wrote:
These modes use interleaving and randomize data values by
exclusive-ORing with a pseudorandom binary
In order for amateurs in the U.S. to use any RTTY/data mode other than Baudot,
ASCII or AMTOR over 2FSK they must be able to point to a published technical
specification for the potocol that shows that it is legal. It was condition
that we all agreed to when we were issued a license. When this
A member of this group contacted the FCC, got a ruling, and published it here.
Just remember that you have no legal defense if the FCC decides to take action.
I keep replying to this stuff because some members of this group could led
others into losing their licenses.
73,
John
KD6OZH
-
] Consensus? Is ROS Legal in US?`
I see you have not idea waht is the meaning of Spread spectrum.
Spread spectrum reduce energy density.
--
De: John B. Stephensen kd6...@comcast.net
Para: digitalradio
to see
whether people comply.
73,
John
KD6OZH
- Original Message -
From: Dave Ackrill
To: digitalradio@yahoogroups.com
Sent: Wednesday, February 24, 2010 20:48 UTC
Subject: Re: [digitalradio] Re: Consensus? Is ROS Legal in US?`
John B. Stephensen wrote:
A member
A lawyer with an engineering degree would be the best person to interpret FCC
regulations. The ARRL has engineers and lawyers and deals with the FCC so they
are the best source of free advice in the U.S.
73,
John
KD6OZH
- Original Message -
From: Bob John
To:
CHIP64 is legal above 222 MHz -- they're assuming that the user will notice
that it's spread-spectrum and act accordingly.
73,
John
KD6OZH
- Original Message -
From: jose alberto nieto ros
To: digitalradio@yahoogroups.com
Sent: Wednesday, February 24, 2010 23:30 UTC
is legal because is not a SS modulation.
--
De: John B. Stephensen kd6...@comcast.net
Para: digitalradio@yahoogroups.com
Enviado: jue,25 febrero, 2010 00:47
Asunto: Re: [digitalradio] Is ROS Documentation
The FCC didn't do anything arbitrary or capricious. They read a specification
provided by the author of the software that stated that ROS is a
spread-spectrum mode. They then told the person asking for the FCC's opinion
that they should go by what the author wrote and not use ROS on HF.
The
A new technical description was published so you should see what it describes
-- fixed start and stop sequences using 16 tones with convolutionally coded
data using 128 tones in between.
73,
John
KD6OZH
- Original Message -
From: Steinar Aanesland
To:
The FCC will say that it up to each licensee to check the legality by reading
the new technical specification. Unless someone shows that the spectrum doesn't
match the specification U.S.hams should feel safe using ROS.
73,
John
KD6OZH
- Original Message -
From: Dave Ackrill
Chapter 8 of the 2010 handbook has a short overview of spread-spectrum
techniques that could be applied to either analog or digital modulation. The
original signal cold be anything (BPSK, FSK, FM...) and is phase or frequency
modulated by a pseudorandom sequence in order to spread the signal
There is a technical descrption at http://rosmodem.wordpress.com/. I doesn't
describe the start and stop tone sequences or completely describe the mapping
from the convolutional encoder to the 128 tones used for data. However, it's
more compete than some of the technical specifications on the
The problem is that the FCC regulations are overly complex and people need a
specialized engineering background to interpret some of them. 99% of the
licensees probably can't interpret every word in the regulations so they ask
for help in this forum when something is not clear.
73,
John
signal when
idling
A good portion of the FCC rules is almost cut and paste from ITU standards
which apply worldwide.
--
From: John B. Stephensen kd6...@comcast.net
Reply-To: digitalradio@yahoogroups.com
I had no doubt that it would once the document that the FCC requires was
published. Since European hams don't normally read FCC regulations, it might
be useful for the IARU or RSGB to publish an article about U.S. regulations
so this doesn't happen again.
73,
John
KD6OZH
- Original
The document that the author of ROS originally published, Introduction to ROS:
The Spread Spectrum, contains a good description of frequency-hopping
spread-spectrum (FHSS) techniques. Section 4 describes taking a 250 Hz wide
mode (MFSK16) and spreading it over 2 kHz by shifting the center
The HSMM working group never proposed the use of spread spectrum. It was
interested in getting the maximum data rate into limited bandwidths. SS does
the opposite of what the HSMM WG was interested in. It spreads limited amounts
of data over the maximum bandwidth.
The actual proposal was to
I assumed that people kept using FSK because paths to Europe can have 20-30 Hz
of Doppler spread.
73,
John
KD6OZH
- Original Message -
From: KH6TY
To: digitalradio@yahoogroups.com
Sent: Tuesday, March 09, 2010 19:08 UTC
Subject: Re: [digitalradio] Re: 1976 FCC - Delete all
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