Re this exchange: KJJ response to Keith Armstrong: In a court of law one must swear to tell the truth, the whole truth, and nothing but the truth.
JW: Indeed, but it is, of course, fatuous. One cannot tell if one even KNOWS the whole truth about anything, let alone whether one will be allowed by procedures and/or the wording of questions by counsel, to state the whole truth. KJJ response to JW: It's really neither here nor there relative to the technical argument, but philosophically the statement of truth is hardly fatuous. It would only be fatuous if there were a presupposition of human omniscience. It is understood by all that the terminology inherently implies the caveat, "the truth as understood by the subject." And as far as what counsel will or will not allow, the truth uttered in court is also subject to the restriction as what is necessary to know and not unfairly prejudicial. Now on to the technical issue. KJJ response to Keith Armstrong: What you stated below is merely part of the truth. The rest of the truth is that spurious emissions emitted by unintentional radiators (the kinds of emissions controlled by CISPR 22 and Title 47, part 15B of the US Code of Federal Regulations) are at such low levels that there is no ability to cause an adverse reaction to anything except a radio receiver. It is only the field intensities associated with intentional rf transmissions that are capable of stimulating electronics operating at higher levels than radio receivers. JW: Well, not 'no' ability, but the probability of significant interference is extremely low in the vast majority of cases. Of course, where safety- of-life is involved, we want the probability to be of the order of 10^-9, but this is not generally very difficult. Highly-sensitive systems should have very high immunity, and this includes receivers, in respect of out-of-band signals. It seems that civilian aircraft electronic systems do not have a very high level of immunity. We can begin to see why this subject is controversial. KJJ response to JW: The aircraft receivers in question are just that, radio receivers, and as such are the sensitive victims protected by CE and RE limits as I described earlier. There is nothing controversial here at all. The fact that personal consumer electronics may be able to affect such radios is not surprising. It is not necessary to assume an out-of-band response, either. ------------------------------------------- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson: pstc_ad...@garretson.org Dave Heald davehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
