This, as we say in the lightning fast chicken navy, the following is simply BS : Anyone with DigiPan or any other PSK31 program with a waterfall can verify that the frequency spreading is random and not a function of the data, which is the signature of spread-spectrum.
The use of a randomizer is not the mark of spread spectrum, but rather the mark of a well-designed modem system, where a steady state data in does not cause a lack of random transmit link data. The receiver needs a steady stream of clock transitions in order to maintain receive synchronization. The transmit waveform needs a steady stream of pseudorandom data in order to maintain a minimum carrier spectral density, than therefore reduce its potential to other users. That is to say, making your transmit waveform appear noise like (I did NOT say, under the noise), gives other modems the best chance be minimally affected. Randomness is not a differential to uniquely identify a spread spectrum modulation. However, every spread spectrum system is pseudorandom. A does not mean B, but B is A. Lester B Veenstra MØYCM K1YCM <mailto:[email protected]> [email protected] <mailto:[email protected]> [email protected] <mailto:[email protected]> [email protected] US Postal Address: PSC 45 Box 781 APO AE 09468 USA UK Postal Address: Dawn Cottage Norwood, Harrogate HG3 1SD, UK Telephones: Office: +44-(0)1423-846-385 Home: +44-(0)1943-880-963 Guam Cell: +1-671-788-5654 UK Cell: +44-(0)7716-298-224 US Cell: +1-240-425-7335 Jamaica: +1-876-352-7504 This e-mail and any documents attached hereto contain confidential or privileged information. The information is intended to be for use only by the individual or entity to whom they are addressed. If you are not the intended recipient or the person responsible for delivering the e-mail to the intended recipient, be aware that any disclosure, copying, distribution or use of the contents of this e-mail or any documents attached hereto is prohibited. From: [email protected] [mailto:[email protected]] On Behalf Of KH6TY Sent: Monday, July 12, 2010 12:21 PM To: [email protected] Subject: Re: [digitalradio] Moving ROS forward in the USA? Andy, I have been told by a FCC engineer, part of the evaluation group at the FCC, whom I will not name, that ROS 16 baud and 1 baud has been evaluated in the lab and "is" spread-spectrum and therefore illegal on HF, not only because the author first said it was spread spectrum and then changed his story. Anyone with DigiPan or any other PSK31 program with a waterfall can verify that the frequency spreading is random and not a function of the data, which is the signature of spread-spectrum. Just because someone "feels" it is not spread spectrum does not excuse them from following the regulations and those who do not risk the chance of FCC action against them once someone files a complaint. There is no reason for the FCC to "reconsider" their decision, since it is based on analysis as well as the author's declaration. What can be done is to submit a petition to the FCC to allow limited bandwidth spread spectrum on HF by showing it is not harmful to other users of the bands. The instructions for submitting a petition are available on the FCC website. Radio amateurs are responsible for following the regulations, not just interpreting them as they see fit. ROS is legal above 222 Mhz, so freely use it there if you wish. It is probably really good for EME. 73, Skip KH6TY _._,___
