Good day: I can't help myself. :-)
The "usual" definition of an S9 signal is 50 uVolts, or -73 dBm (assuming a 50 Ohm load). The "S-Meter" unit is a 6 dB change in VOLTAGE, not power. To get one VOLT, we need 2000 times 50 uVolts, or S9 + about 86dB (86 dB over S9). 40 over is about 5 mVolts... The formula for the dB difference for two voltages, assuming you want a power and have the same load, is 20 * log (V2/V1). If you want dB's "over" S9, let V1 be 50 uV, (50E-6 Volts). Now, let's hope I managed to get this right. :-) 73, Mark ----- Original Message ----- From: "Randy Downs" <randyddo...@gmail.com> To: elecraft@mailman.qth.net, "Jim Brown" <j...@audiosystemsgroup.com> Sent: Monday, May 4, 2009 4:37:01 PM GMT -05:00 US/Canada Eastern Subject: Re: [Elecraft] K3 on-channel strong signal overload? 40 over is several volts? I thought it was around 5 mili volts. That's what I am talking about. I've seen this distortion in signals since several fw revisions ago. If I get time tonight I'll reload some earlier rev's. Randy K8RDD ----- Original Message ----- From: "Jim Brown" <j...@audiosystemsgroup.com> To: "Elecraft List" <elecraft@mailman.qth.net> Sent: Monday, May 04, 2009 2:34 PM Subject: Re: [Elecraft] K3 on-channel strong signal overload? > On Mon, 4 May 2009 14:12:09 -0400, Randy Downs wrote: > >>It's on 10 meters. Should I not run 10 meters? > > Of course not. Just don't be surprised when several volts of on- > frequency RF causes overload. > > 73, > > Jim K9YC > > > ______________________________________________________________ > 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 ______________________________________________________________ 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
