Hi Bill, Supposedly my S/N has the mods already. Nevertheless, I don't use the line output for anything normally and speakers are for listening to music. I won't be wasting my time looking for the problem if I wasn't actually hearing it too in my good quality headphones.
Regards, Wes --- On Mon, 2/2/09, Bill W4ZV <btipp...@alum.mit.edu> wrote: > From: Bill W4ZV <btipp...@alum.mit.edu> > Subject: Re: [Elecraft] K3 AM reception > To: elecraft@mailman.qth.net > Date: Monday, February 2, 2009, 10:01 AM > Wes Stewart wrote: > > > > Following are links to plots that demonstrate some of > the "fun" I'm > > having. The first two are taken using Spectrum Lab to > look at the Line > > Out audio signal from the K3. The input signal is > from a homebrew 28.7 > > MHz crystal oscillator/buffer with about a -70 dBm > output level. For > > these particular plots the K3 mode was set to LSB, > although I saw, but > > didn’t record the same issue on CW. The beat note > is 450 Hz. The Line Out > > is run into the microphone input of the built-in sound > card in my Lenovo > > T400 laptop. Care was taken to insure that the sound > card wasn't being > > overdriven. > > > > Have you done the AF Stage Upgrade? > > "While the K3's speaker and line outputs meet the > original K3 distortion > specifications at their intended levels of operation, > we've found that > further improvement is possible, especially at higher > volume levels, with > minor component changes. Low level distortion products can > be further > reduced at both outputs. These changes are being > incorporated into new K3s." > > http://www.elecraft.com/K3/mods/K3_AF_Stage_Upgrade_Instructions_Rev_B.pdf > > Do you notice the same distortion when using the headphone > output? I have > good ears and a lot of experience on CW. All 3 of the K3s > I've had have > excellent audio fidelity when using a good set of > headphones (headphone > output has apparently never had this problem). This also > sounds very > similar to UR5LAM's issue posted about some 3 months > ago, which I believe > resulted in the above mod. > > 73, Bill > > -- > View this message in context: > http://n2.nabble.com/K3-AM-reception-tp2254009p2259061.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
