On 3/22/2011 7:24 PM, Edward Dickinson III wrote: > The matching network is a $20 item from an auto sound store and is > used to cut speaker level down to line level.
You just spent $20 on something that you could have done equally well with two 5-cent resistors, AND that probably was not needed in the first place. Study the part of http://audiosystemsgroup.com/HamInterfacing.pdf that talks about audio levels. Also see the Appendix on audio that is part of http://audiosystemsgroup.com/RFI-Ham.pdf The executive summary -- most computer sound cards clip at about 1 volt sine wave. A 2-watt power amp, typical for ham gear, would clip at about 2 volts, and that only occurs on very loud audio peaks. All that's required to prevent clipping of the sound card input is to turn the speaker output gain down a bit. A simple voltage divider (the two resistors) IS needed to drive a MIC level input. 73, Jim K9YC ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
