Dears I've seen on the manual S9 /50 microvolts is adjusted with Preamp ON . As a new Elecrafter I need some explanations, because with my previous rigs, I use to calibrate S9 without the preamp. Thanks Philippe A65BI K3 #3616
>>> Bill W4ZV <btipp...@alum.mit.edu> 17-11-2009 22:25 >>> Geoffrey Downs-2 wrote: > > A couple of years ago there was some correspondence on the reflector about > whether an S unit is 6db or 4 db and there appears to be historical > precedent for both but I have looked at the archive and can't find where > it > rested as far as the K3 is concerned. It occurred to me while recently > re-calibrating my S meter with the XG2 that if, in accordance with the > manual, you set S9 to be 50 microvolts and adopt 6 db per S unit the > reading > for 1 microvolt should be between S3 and S4 (S3 being 0.78 microvolts and > S4 > 1.56 microvolts by my calculations). For practical purposes S3 is probably > close enough rather than "about S2 or 3" as shown in the manual. Or is it > more complicated than that? My arithmetic is not up working out how many S > units one microvolt would be at 4db per S unit but I suspect it would be > further away from S2 or 3. Anyone care to comment? > I believe 6 dB is the "correct" definition, but most S-meters (K3 and Flex 5k excluded) are very non-linear at low S-meter readings. IMHO the following is an accurate summary of what readings should be: http://www.n6rk.com/S_unit_definitions.doc I would adjust the K3 for the XG2's 1 uV output to solidly display S3 (i.e. no flicker of S2-3). That would only be 2.16 dB off (20 log .78/1), which is probably "close enough". 73, Bill -- View this message in context: http://n2.nabble.com/Re-K3-S-Meter-tp4019422p4020331.html Sent from the Elecraft mailing list archive at Nabble.com. ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
