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.
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