I finally had the chance to put my KX3 together over the weekend! Yay! I don't know if it's the same thing you're hearing, but there is a high pitched whine in the audio on my unit (it transfers from the speaker to the headphones when they're plugged in). Sounds like a G/G# ... maybe something in the 12.8 khz range? I don't have access to anything right now that can actually measure it. The volume of the tone doesn't change with AF gain -- tho what AF Gain mean in this radio is non-obvious :). It also doesn't change with band or mode, nor with a change of power supply (three different external supplies), nor location, nor presence or absence of antenna. I have the ATU and filter, no battery charger. I can easily hear it using the internal speaker, but I'm hoping I can fix that with a judiciously chosen capacitor across the speaker leads. I essentially can't hear it on my Heil cans, so I'll be fine this Field Day, but it turns up clearly on ear buds, so I'd like to fix that side as well. I don't recall having heard it on anyone else's KX3, but stuff in this range is pretty easy to either miss or misattribute unless you have good high frequency hearing and you're by yourself in a quiet room, and it could also vary from unit to unit. Finally, I won't claim to be pitch accurate up there, but until I can measure it on something, a good guess is better than nothing :).
-kb7psg On Fri, 2 Nov 2012, David F. Reed wrote:
I notice a high pitched hum (low level) when my KX3 is on, after installing the KXBC3; has anyone else noticed this? What might be causing it? Is it possible to eliminate? Other than the hum, everything seems to be normal and working fine. Thanks and 73 de Dave, W5SV
______________________________________________________________ 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
