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On Fri, 24 Jan 2014 20:29:22 -0500, Jerry Stuckle
wrote: Receiver sensitivity was 0.2 mv for 20db S+N/N ratio. I'll assume that you mean 0.2 microvolts, not millivolts. Also, nobody has uses 20dB S+N/N since about the 1960's except maybe the ARRL[1]. 12dB SINAD has been around since about the mid 1960's. http://en.wikipedia.org/wiki/SINAD I don't know how much better; the surplus signal generator I was using wasn't that accurate. At the time, I used a Gertsch FM-something. It's the box with only the left handle showing at the extreme right of the pictu http://802.11junk.com/jeffl/pics/Old%20Repeaters/slides/PMC02.html It wasn't every accurate, and not really intended to be used as a signal source. However, I had a precision step attenuator, and since the Gertsch factory was near my parents house, it wasn't too difficult to get it calibrated in trade for some grunt work. And BTW - 'm' can also mean micro, especially when you don't have a Greek alphabet available. 'u' is not the same as the Greek 'mu' and can be confusing. Of course, using 'm' for both milli and micro can be confusing, unless you know the context. If you follow SI standards, the "m" means milli. http://physics.nist.gov/cuu/Units/prefixes.html If you have a PC keyboard, try using the key combination: alt0181 on the number pad which produces a µ symbol. http://symbolcodes.tlt.psu.edu/accents/codealt.html [1] It took me about 10 years to stop using micro-microfarads and switch to picofarads. I suppose there might be some dinosaurs roaming the earth still talking about "20 dB quieting". -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
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