Hi,
I think I found the problem. Since I had another K3 I took the KR mixer board from one of the radios and put in the one with the problem and the noise went away. So I started measuring on the board and as soon as I put the oscilloscope probe on the +5V pin the noise went away. So by the looks of the schematic +5V is fed into a voltage divider which is also connected to the LO and switches the multiplexer doing the mixing. So I measured the voltage at the input to the "mixer" and the peak level was right at +2V which is also the Vih of the circuit. So I guess it ended up barely switching any thus just generating noise instead. By adjusting it so it switches properly the problem went away. 73 de Mike, SM2WMV (SJ2W) http://www.sj2w.se/contest/ On 8 November 2019 at 23:26:32 +01:00, Mikael Larsmark <[email protected]> wrote: > Hi again, > > I tried the factory settings and the problem does remain. I made a Youtube > clip which shows it and the noise goes away below 1320kHz and above 2150kHz. > > > Here is the clip,<<https://youtu.be/Ju5oMhq2YEE>> > > > So I really feel this is a problem in the radio and not anything else. > 73 de Mike, SM2WMV (SJ2W) > <http://www.sj2w.se/contest/> > > > On 8 November 2019 at 22:53:25 +01:00, RIchard Williams > <<[email protected]>> wrote: > > > > Well, that was a good idea (only works if you have a second radio). I would > > try Eric's suggestion to reload a good EEINIT file. Can't beat Elecraft for > > support. > > > > > > Dick, K8ZTT > > > > > > > > Sent from Yahoo Mail on Android > > <<https://go.onelink.me/107872968?pid=InProduct&c=Global_Internal_YGrowth_AndroidEmailSig__AndroidUsers&af_wl=ym&af_sub1=Internal&af_sub2=Global_YGrowth&af_sub3=EmailSignature>> > > > > > > > > > On Fri, Nov 8, 2019 at 11:28, Mikael Larsmark > > > <<[email protected]>> wrote: > > > > > > Hi Dick, > > > > > > I have tried plugging everything out of the radio except the power > > > supply. Then I took another K3 and made sure I did not have the same > > > problem on that radio which I did not have, it was totally quiet when > > > unplugging the antennas. I took the power supply cable from that K3 and > > > plugged into the one with problem (still no other cables connected) and > > > still the same noise. I also tried a dummy load on the TX ant port but no > > > success. > > > > > > > > > So I doubt it is anything generated locally since the setup is identical > > > with the other K3 when switching them out. Plus it is dead quiet on all > > > other bands when unplugging the antennas. > > > 73 de Mike, SM2WMV (SJ2W) > > > <<http://www.sj2w.se/contest/>> > > > > > > > > > On 8 November 2019 at 21:55:26 +01:00, RIchard Williams > > > <<<[email protected]>>> wrote: > > > > > > > > > > First, I would try using just a battery to make sure it is not power > > > > supply. Then try turning off everything but your radio in the shack. If > > > > the noise is still there, throw the master breaker to the house to see > > > > if it might be something in your house. > > > > > > > > > > > > Or you might take your radio and a battery somewhere that is not near > > > > any noise sources and see what your S meter shows. If you still have > > > > the noise, maybe someone else has some thoughts. > > > > > > > > > > > > Dick, K8ZTT > > > > > > > > Sent from Yahoo Mail on Android > > > > <<https://go.onelink.me/107872968>?pid=InProduct&c=Global_Internal_YGrowth_AndroidEmailSig__AndroidUsers_wl=ym_sub1=Internal_sub2=Global_YGrowth_sub3=EmailSignature > > > > > > > > <<https://go.onelink.me/107872968?pid=InProduct&c=Global_Internal_YGrowth_AndroidEmailSig__AndroidUsers&af_wl=ym&af_sub1=Internal&af_sub2=Global_YGrowth&af_sub3=EmailSignature>>> > > > > > > > > > > > > > > > > > On Fri, Nov 8, 2019 at 10:01, Mikael Larsmark > > > > > <<<[email protected]>>> wrote: > > > > > > > > > > Hi, > > > > > > > > > > I am having an issue which confuses me quite a bit. When I unplug my > > > > > antennas and listen to 80m for example I have very low noise and the > > > > > S-meter does not light up a single bar. When I go to 160m and do the > > > > > same thing I have S3-S4 and I can hear a much higher noise level. It > > > > > is the same behavior regardless if I use the RX antenna or the ANT1 > > > > > jack (none with any antenna). I have the same settings on both bands. > > > > > > > > > > > > > > > I also tried to do a factory reset but behavior remains. > > > > > Any idea what this can be? > > > > > > > > > > /Mikael, SJ2W > > > > > ______________________________________________________________ > > > > > 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>>> > > > > > Message delivered to <<<[email protected]>>> > > > > > > > > > > > > > > > > > > > > > > > > > > > > ______________________________________________________________ > > > 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>> > > > Message delivered to <<[email protected]>> > > > > > > > ______________________________________________________________ > 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> > Message delivered to <[email protected]> > ______________________________________________________________ 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 Message delivered to [email protected]
