Oops, someone pointed out an ambiguity, the last line should have read "...it has the potential as a noise generating device that can be controlled".
Quoting [EMAIL PROTECTED]: > We have the facilities. There are a number of ways of generating comparison > data: > > - Controlled signal O/P, over-the-air especially valid if performed within > the > confines of an anechoic chamber. > - Direct measurement (COAX soldered directly to the board) using a modulated > > signal whose power can be accurately attenuated > > When I tested a number of RX's some 10 years ago all were acceptable, in fact > > within a few dB of each other. > > As to the validity of performing back to back comparisons I'm not sure there > is > any value in it, especially from a consumer standpoint. The measurements are > > irrelevant given that every end-user installation is different, and has > significantly more bearing on system (signal) integrity than the actual RX > sensitivity. > > The waters a muddied now, especially with onboard smarts which are becoming > more effective at discerning the intended signal in order to maintain > communication integrity. > > With this last statement, the actual measurement (in dBm) where a particular > RX > will no longer respond to a valid signal will be similar amongst the current > > crop of RX's be it smart or not-so-smart (no onboard uprocessors). > > Just how effective a RX with onboard smarts can differentiate the correct > signal under less than ideal circumstances (some sort of controlled > extraneous > EMI/RFI) would probably be of more value. > > This is where differing opinions start to play a part. As to what sort of > test > parameters would emulate the above premise, and be an acceptable means of > gathering data would be valid discussion to start with. > > We had to design a RX which would allow wireless data acquisition to check > the > mechanical integrity of super large combustion engines on gas trasmission > lines. Lot's of EMI/RFI from multiple spark ignition systems. As a spark in > itself generates EMI/RFI from DC well up into the GHz, it has the potential > as > a noise generating device that cantbe controlled. > > > Quoting Bill Swingle <[EMAIL PROTECTED]>: > > > >>Has anyone ever sat at their workbench and measured... > > >>Who has the tools? > > > > Good question. Tom Hoopes has done this. His data looked pretty good. But > > it's been a while since I've seen him publish any more info. > > > > I mentioned at the time that I'd like to see a "Hoopes Approved" sticker > but > > that didn't go anywhere. > > > > Very few have the tools and smarts to perform the hard numbers testing AND > > know how to apply it. There's just no money in doing it. Tom seemed to do > > well. George Steiner could. Heck, maybe Simon and a few others. But, it's > > not something to be taken lightly. > > > > What you're asking for a "Consumer Reports" style of evaluation. I've seen > > nothing like that since the "Hoopes" evaluation of several years ago. > > > > This is why I don't buy the latest and greatest RX's. I wait for some > field > > confirmations. It isn't great but it's the best we have available. > > > > Bill Swingle > > > > > > > > RCSE-List facilities provided by Model Airplane News. Send "subscribe" > and > > "unsubscribe" requests to [EMAIL PROTECTED] Please note that > > subscribe and unsubscribe messages must be sent in text only format with > MIME > > turned off. Email sent from web based email such as Hotmail and AOL are > > generally NOT in text format > > > > > Simon Van Leeuwen > PnP Systems - The E-Harness of Choice > Radius Systems > Cogito Ergo Zoom > > RCSE-List facilities provided by Model Airplane News. Send "subscribe" and > "unsubscribe" requests to [EMAIL PROTECTED] Please note that > subscribe and unsubscribe messages must be sent in text only format with MIME > turned off. Email sent from web based email such as Hotmail and AOL are > generally NOT in text format > Simon Van Leeuwen PnP Systems - The E-Harness of Choice Radius Systems Cogito Ergo Zoom RCSE-List facilities provided by Model Airplane News. Send "subscribe" and "unsubscribe" requests to [EMAIL PROTECTED] Please note that subscribe and unsubscribe messages must be sent in text only format with MIME turned off. Email sent from web based email such as Hotmail and AOL are generally NOT in text format
