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K3S Audio buzz on transmit, especially AM

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Nicklas Johnson

Re: K3S Audio buzz on transmit, especially AM

Sorry for the additional email, but this is particularly interesting: it
occurred to me that I'd never tried the reverse setup, so I put the KX3 in
transmit mode and 0.1W on AM in another room, and set the K3S on receive.
And sure enough, the K3S immediately started picking up S40 of buzzing
noise. However if I tune the K3S to an AM broadcast station or WWV, no
buzz. So either both the K3S and KX3 are being affected on transmit in the
same way (which seems implausible but not impossible), or possibly
something else is going on at my QTH.

On the P3, I definitely see the noise when the KX3 is transmitting from the
other room.

Now I wish I had a scope so I could see what the AM carrier generated by
the KX3 and K3S looks like so I could tell if this is something that's
happening inside the transmitter, or something that is happening because of
some outside influence mixing powerline noise with the AM carrier. The
important thing to me is that the carrier I'm putting out there is clean...
if there's some local mixing that happens that means I can't listen to my
own transmission without a buzz, I can live with that.

One kind of curious thing is that there's also a superimposed "squeaky
wheel" sound at random intervals detectable when the KX3 is transmitting an
AM carrier, and not otherwise, and also not when listening to WWV or AM
broadcast, which vaguely seems to correlate with how windy it is at any
given moment. Could all of this be a "rusty bolt" effect from something in
the vicinity?

Nick

On Fri, 26 Apr 2019 at 18:11, Nicklas Johnson <[hidden email]> wrote:

> A few more data points:
>
> Changing TX EQ, including cutting the first 4 bands all the way down to
> -16 had no effect on the received signal.
>
> Plugging in some headphones, turning the TX Monitor up all the way, I
> don't detect the hum in the TX monitor signal either in TX test mode,
> transmitting into a dummy load, or even transmitting into the antenna with
> very low power. If I turn up the Line In level, I just hear expected white
> noise on the TX monitor. So at least as far along the path as the TX
> monitor, there's no hum or buzz introduced.
>
> Switching the receiver (a KX3) to USB mode and using one leg of a
> buddistick as an antenna so I can walk around, the noise received around
> the house and outside is around S4 when transmitting about 100mW into the
> antenna, though it varies some as I walk around.
>
> I do have a set of power lines running through my back yard, and where I
> live in San Mateo, you're always near somebody's wiring for something,
> unfortunately... my neighbor's south wall is possibly as far as 8 feet away
> from my north wall, etc.
>
> It looks like two phases running along the top, then a transformer to two
> phases and a neutral along the bottom, to which people's houses are
> connected.
>
> We also have underground utilities on our street, including a big green
> transformer that sits in the corner of our front lawn.
>
> I think the next test will be to take the K3S and the KX3 some distance
> away from all of these things and see if the hum goes away, and if it does,
> then figure out what thing the K3S needs to get away from in particular.
> If it's the powerlines in my back yard or the transformer in my front yard,
> then that'll be a difficult problem.
>
> Nick
>
>
>
> On Fri, 26 Apr 2019 at 17:28, Bob McGraw K4TAX <[hidden email]>
> wrote:
>
>> Yes but the EQ is in the digital path. The EQ should be done there,
>> preferably after the MIC input. The AM BW does not attenuate the end like
>> the SSB filter.
>>
>> I suggest -16 dB on the first 3 bands.
>>
>> Bob, K4TAX
>>
>>
>> Sent from my iPhone
>>
>> > On Apr 26, 2019, at 6:38 PM, Nicklas Johnson <[hidden email]> wrote:
>> >
>> > Flat, except I turned the first one down a few notches, which doesn't
>> > really do much in my case because both the microphone and mixer that I
>> use
>> > (when they're actually connected) roll off below 150 and 80 Hz
>> > respectively. It had previously been suggested to me that rolling off
>> low
>> > frequency cruft is a good idea for AM and SSB.
>> >
>> > Nick
>> >
>> >> On Fri, 26 Apr 2019 at 15:57, Bob McGraw K4TAX <[hidden email]>
>> wrote:
>> >>
>> >> I recall commenting earlier. What TX EQ values are being used for AM.
>> ?
>> >>
>> >> Bob, K4TAX
>> >>
>> >>
>> >> Sent from my iPhone
>> >>
>> >>> On Apr 26, 2019, at 5:48 PM, Nicklas Johnson <[hidden email]> wrote:
>> >>>
>> >>> My desk in this case sits adjacent a wall, and there's only a shower
>> on
>> >> the
>> >>> other side of that wall. I did turn off everything in the vicinity of
>> >> the
>> >>> desk and all the lights in the room (I've in fact heard a very similar
>> >> hum
>> >>> from the switching power supply for my mixer, and my first thought
>> was it
>> >>> was this that was being picked up), but I didn't turn off the
>> computer on
>> >>> the other side of the room. In this case it will be easier to move
>> the
>> >> rig
>> >>> outdoors with a battery than it will be to turn that computer off for
>> the
>> >>> moment. It would have to be an impressively/obnoxiously strong
>> magnetic
>> >>> field from that side of the room to influence the transformers inside
>> the
>> >>> rig 8 feet away, but it's worth trying and simple enough to rule it
>> out.
>> >>>
>> >>> Nick
>> >>>
>> >>>> On Fri, 26 Apr 2019 at 14:51, Don Wilhelm <[hidden email]>
>> >> wrote:
>> >>>>
>> >>>> In addition to operating from a battery isolated from the solar
>> system,
>> >>>> I would recommend that you do a quick test - remove all cables from
>> the
>> >>>> K3S except the power cable and a coax to a dummy load. Power down
>> all
>> >>>> power supplies in your station, including any desk lamps.
>> >>>> Go into Transmit by tapping the XMIT button.
>> >>>> Is the hum still present? If not, then start connecting things to
>> your
>> >>>> K3S one at a time, doing the same test after each thing connected.
>> >>>>
>> >>>> Of course, if the hum is present with nothing connected, contact
>> >>>> [hidden email] - but I cannot imagine a hum with harmonics of
>> 60
>> >>>> Hz being induced if you take away all the 60 Hz operated sources in
>> the
>> >>>> area.
>> >>>>
>> >>>> 73,
>> >>>> Don W3FPR
>> >>>>
>> >>>> --
>> >>> *N6OL*
>> >>> Saying something doesn't make it true. Belief in something doesn't
>> make
>> >> it
>> >>> real. And if you have to lie to support a position, that position is
>> not
>> >>> worth supporting.
>> >>> ______________________________________________________________
>> >>> Elecraft mailing list
>> >>> Home: http://mailman.qth.net/mailman/listinfo/elecraft
>> >>> Help: http://mailman.qth.net/mmfaq.htm
>> >>> Post: mailto:[hidden email]
>> >>>
>> >>> This list hosted by: http://www.qsl.net
>> >>> Please help support this email list: http://www.qsl.net/donate.html
>> >>>
>> >>
>> >>
>> >
>> > --
>> > *N6OL*
>> > Saying something doesn't make it true. Belief in something doesn't
>> make it
>> > real. And if you have to lie to support a position, that position is not
>> > worth supporting.
>> > ______________________________________________________________
>> > Elecraft mailing list
>> > Home: http://mailman.qth.net/mailman/listinfo/elecraft
>> > Help: http://mailman.qth.net/mmfaq.htm
>> > Post: mailto:[hidden email]
>> >
>> > This list hosted by: http://www.qsl.net
>> > Please help support this email list: http://www.qsl.net/donate.html
>> >
>>
>>
>>
>
> --
> *N6OL*
> Saying something doesn't make it true. Belief in something doesn't make
> it real. And if you have to lie to support a position, that position is not
> worth supporting.
>

Bob McGraw - K4TAX

Re: K3S Audio buzz on transmit, especially AM

I think Jim's concern, expressed earlier, about power line neutral distortion components is valid. And it may be originating in "the big green transformer" in the yard.

Bob, K4TAX

Sent from my iPhone

> On Apr 26, 2019, at 8:53 PM, Nicklas Johnson <[hidden email]> wrote:
>
> Sorry for the additional email, but this is particularly interesting: it
> occurred to me that I'd never tried the reverse setup, so I put the KX3 in
> transmit mode and 0.1W on AM in another room, and set the K3S on receive.
> And sure enough, the K3S immediately started picking up S40 of buzzing
> noise. However if I tune the K3S to an AM broadcast station or WWV, no
> buzz. So either both the K3S and KX3 are being affected on transmit in the
> same way (which seems implausible but not impossible), or possibly
> something else is going on at my QTH.
>
> On the P3, I definitely see the noise when the KX3 is transmitting from the
> other room.
>
> Now I wish I had a scope so I could see what the AM carrier generated by
> the KX3 and K3S looks like so I could tell if this is something that's
> happening inside the transmitter, or something that is happening because of
> some outside influence mixing powerline noise with the AM carrier. The
> important thing to me is that the carrier I'm putting out there is clean...
> if there's some local mixing that happens that means I can't listen to my
> own transmission without a buzz, I can live with that.
>
> One kind of curious thing is that there's also a superimposed "squeaky
> wheel" sound at random intervals detectable when the KX3 is transmitting an
> AM carrier, and not otherwise, and also not when listening to WWV or AM
> broadcast, which vaguely seems to correlate with how windy it is at any
> given moment. Could all of this be a "rusty bolt" effect from something in
> the vicinity?
>
> Nick
>
>
>
>> On Fri, 26 Apr 2019 at 18:11, Nicklas Johnson <[hidden email]> wrote:
>>
>> A few more data points:
>>
>> Changing TX EQ, including cutting the first 4 bands all the way down to
>> -16 had no effect on the received signal.
>>
>> Plugging in some headphones, turning the TX Monitor up all the way, I
>> don't detect the hum in the TX monitor signal either in TX test mode,
>> transmitting into a dummy load, or even transmitting into the antenna with
>> very low power. If I turn up the Line In level, I just hear expected white
>> noise on the TX monitor. So at least as far along the path as the TX
>> monitor, there's no hum or buzz introduced.
>>
>> Switching the receiver (a KX3) to USB mode and using one leg of a
>> buddistick as an antenna so I can walk around, the noise received around
>> the house and outside is around S4 when transmitting about 100mW into the
>> antenna, though it varies some as I walk around.
>>
>> I do have a set of power lines running through my back yard, and where I
>> live in San Mateo, you're always near somebody's wiring for something,
>> unfortunately... my neighbor's south wall is possibly as far as 8 feet away
>> from my north wall, etc.
>>
>> It looks like two phases running along the top, then a transformer to two
>> phases and a neutral along the bottom, to which people's houses are
>> connected.
>>
>> We also have underground utilities on our street, including a big green
>> transformer that sits in the corner of our front lawn.
>>
>> I think the next test will be to take the K3S and the KX3 some distance
>> away from all of these things and see if the hum goes away, and if it does,
>> then figure out what thing the K3S needs to get away from in particular.
>> If it's the powerlines in my back yard or the transformer in my front yard,
>> then that'll be a difficult problem.
>>
>> Nick
>>
>>
>>
>> On Fri, 26 Apr 2019 at 17:28, Bob McGraw K4TAX <[hidden email]>
>> wrote:
>>
>>> Yes but the EQ is in the digital path. The EQ should be done there,
>>> preferably after the MIC input. The AM BW does not attenuate the end like
>>> the SSB filter.
>>>
>>> I suggest -16 dB on the first 3 bands.
>>>
>>> Bob, K4TAX
>>>
>>>
>>> Sent from my iPhone
>>>
>>>> On Apr 26, 2019, at 6:38 PM, Nicklas Johnson <[hidden email]> wrote:
>>>>
>>>> Flat, except I turned the first one down a few notches, which doesn't
>>>> really do much in my case because both the microphone and mixer that I
>>> use
>>>> (when they're actually connected) roll off below 150 and 80 Hz
>>>> respectively. It had previously been suggested to me that rolling off
>>> low
>>>> frequency cruft is a good idea for AM and SSB.
>>>>
>>>> Nick
>>>>
>>>>> On Fri, 26 Apr 2019 at 15:57, Bob McGraw K4TAX <[hidden email]>
>>> wrote:
>>>>>
>>>>> I recall commenting earlier. What TX EQ values are being used for AM.
>>> ?
>>>>>
>>>>> Bob, K4TAX
>>>>>
>>>>>
>>>>> Sent from my iPhone
>>>>>
>>>>>> On Apr 26, 2019, at 5:48 PM, Nicklas Johnson <[hidden email]> wrote:
>>>>>>
>>>>>> My desk in this case sits adjacent a wall, and there's only a shower
>>> on
>>>>> the
>>>>>> other side of that wall. I did turn off everything in the vicinity of
>>>>> the
>>>>>> desk and all the lights in the room (I've in fact heard a very similar
>>>>> hum
>>>>>> from the switching power supply for my mixer, and my first thought
>>> was it
>>>>>> was this that was being picked up), but I didn't turn off the
>>> computer on
>>>>>> the other side of the room. In this case it will be easier to move
>>> the
>>>>> rig
>>>>>> outdoors with a battery than it will be to turn that computer off for
>>> the
>>>>>> moment. It would have to be an impressively/obnoxiously strong
>>> magnetic
>>>>>> field from that side of the room to influence the transformers inside
>>> the
>>>>>> rig 8 feet away, but it's worth trying and simple enough to rule it
>>> out.
>>>>>>
>>>>>> Nick
>>>>>>
>>>>>>> On Fri, 26 Apr 2019 at 14:51, Don Wilhelm <[hidden email]>
>>>>> wrote:
>>>>>>>
>>>>>>> In addition to operating from a battery isolated from the solar
>>> system,
>>>>>>> I would recommend that you do a quick test - remove all cables from
>>> the
>>>>>>> K3S except the power cable and a coax to a dummy load. Power down
>>> all
>>>>>>> power supplies in your station, including any desk lamps.
>>>>>>> Go into Transmit by tapping the XMIT button.
>>>>>>> Is the hum still present? If not, then start connecting things to
>>> your
>>>>>>> K3S one at a time, doing the same test after each thing connected.
>>>>>>>
>>>>>>> Of course, if the hum is present with nothing connected, contact
>>>>>>> [hidden email] - but I cannot imagine a hum with harmonics of
>>> 60
>>>>>>> Hz being induced if you take away all the 60 Hz operated sources in
>>> the
>>>>>>> area.
>>>>>>>
>>>>>>> 73,
>>>>>>> Don W3FPR
>>>>>>>
>>>>>>> --
>>>>>> *N6OL*
>>>>>> Saying something doesn't make it true. Belief in something doesn't
>>> make
>>>>> it
>>>>>> real. And if you have to lie to support a position, that position is
>>> not
>>>>>> worth supporting.
>>>>>> ______________________________________________________________
>>>>>> Elecraft mailing list
>>>>>> Home: http://mailman.qth.net/mailman/listinfo/elecraft
>>>>>> Help: http://mailman.qth.net/mmfaq.htm
>>>>>> Post: mailto:[hidden email]
>>>>>>
>>>>>> This list hosted by: http://www.qsl.net
>>>>>> Please help support this email list: http://www.qsl.net/donate.html
>>>>>>
>>>>>
>>>>>
>>>>
>>>> --
>>>> *N6OL*
>>>> Saying something doesn't make it true. Belief in something doesn't
>>> make it
>>>> real. And if you have to lie to support a position, that position is not
>>>> worth supporting.
>>>> ______________________________________________________________
>>>> Elecraft mailing list
>>>> Home: http://mailman.qth.net/mailman/listinfo/elecraft
>>>> Help: http://mailman.qth.net/mmfaq.htm
>>>> Post: mailto:[hidden email]
>>>>
>>>> This list hosted by: http://www.qsl.net
>>>> Please help support this email list: http://www.qsl.net/donate.html
>>>>
>>>
>>>
>>>
>>
>> --
>> *N6OL*
>> Saying something doesn't make it true. Belief in something doesn't make
>> it real. And if you have to lie to support a position, that position is not
>> worth supporting.
>>
>
>
> --
> *N6OL*
> Saying something doesn't make it true. Belief in something doesn't make it
> real. And if you have to lie to support a position, that position is not
> worth supporting.
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> 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:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html

W2xj

Re: K3S Audio buzz on transmit, especially AM

In reply to this post by Nicklas Johnson

Sounds like some internal RF feedback.

Sent from my iPad

> On Apr 26, 2019, at 11:43 AM, Nicklas Johnson <[hidden email]> wrote:
>
> This morning just for yuks, I also temporarily disconnected the ground from
> the rig entirely while also connecting only to a dummy load, so there could
> be no path to ground at all, let alone multiple paths. No change.
>
> I guess the next things I'll probably try are a full factory reset, and
> then perhaps popping it open to make sure nothing has come unseated. But
> first I'll drop a line to Elecraft support too. I've seen a number of
> people post about similar problems that either magically resolved
> themselves or ended up being a fault on the audio board.
>
> Nick
>
>
>> On Thu, 25 Apr 2019 at 23:27, Nicklas Johnson <[hidden email]> wrote:
>>
>> Again, the problem persists with all inputs completely disconnected and
>> the mic gain set at 0. And running solely on a battery into a dummy load.
>>
>> Nick
>>
>> On Thu, Apr 25, 2019, 10:10 PM Jim Brown <[hidden email]>
>> wrote:
>>
>>>> On 4/25/2019 8:15 PM, Nicklas Johnson wrote:
>>>> Physically touching the case or grabbing the barrel of the front panel
>>> mic
>>>> connector actually does cause the buzz to get just a little softer.
>>>
>>> I suspect either a bonding problem or a problem with the wiring of the
>>> mic.
>>>
>>>> I generally use solar/battery power, though my ground is bonded to my
>>>> utility ground.
>>>
>>> I suggest that you carefully study either N0AX's recent ARRL book on
>>> grounding and bonding, or the slides for talks I've given at Visalia and
>>> Pacifion.
>>>
>>> 73, Jim K9YC
>>>
>>> ______________________________________________________________
>>> Elecraft mailing list
>>> Home: http://mailman.qth.net/mailman/listinfo/elecraft
>>> Help: http://mailman.qth.net/mmfaq.htm
>>> Post: mailto:[hidden email]
>>>
>>> This list hosted by: http://www.qsl.net
>>> Please help support this email list: http://www.qsl.net/donate.html
>>>
>>
>
> --
> *N6OL*
> Saying something doesn't make it true. Belief in something doesn't make it
> real. And if you have to lie to support a position, that position is not
> worth supporting.
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>

W2xj

Re: K3S Audio buzz on transmit, especially AM

In reply to this post by Bob McGraw - K4TAX

EQ should have nothing to do with solving the problem. EQ just masks it.

Sent from my iPad

> On Apr 26, 2019, at 6:56 PM, Bob McGraw K4TAX <[hidden email]> wrote:
>
> I recall commenting earlier. What TX EQ values are being used for AM. ?
>
> Bob, K4TAX
>
>
> Sent from my iPhone
>
>> On Apr 26, 2019, at 5:48 PM, Nicklas Johnson <[hidden email]> wrote:
>>
>> My desk in this case sits adjacent a wall, and there's only a shower on the
>> other side of that wall. I did turn off everything in the vicinity of the
>> desk and all the lights in the room (I've in fact heard a very similar hum
>> from the switching power supply for my mixer, and my first thought was it
>> was this that was being picked up), but I didn't turn off the computer on
>> the other side of the room. In this case it will be easier to move the rig
>> outdoors with a battery than it will be to turn that computer off for the
>> moment. It would have to be an impressively/obnoxiously strong magnetic
>> field from that side of the room to influence the transformers inside the
>> rig 8 feet away, but it's worth trying and simple enough to rule it out.
>>
>> Nick
>>
>>> On Fri, 26 Apr 2019 at 14:51, Don Wilhelm <[hidden email]> wrote:
>>>
>>> In addition to operating from a battery isolated from the solar system,
>>> I would recommend that you do a quick test - remove all cables from the
>>> K3S except the power cable and a coax to a dummy load. Power down all
>>> power supplies in your station, including any desk lamps.
>>> Go into Transmit by tapping the XMIT button.
>>> Is the hum still present? If not, then start connecting things to your
>>> K3S one at a time, doing the same test after each thing connected.
>>>
>>> Of course, if the hum is present with nothing connected, contact
>>> [hidden email] - but I cannot imagine a hum with harmonics of 60
>>> Hz being induced if you take away all the 60 Hz operated sources in the
>>> area.
>>>
>>> 73,
>>> Don W3FPR
>>>
>>> --
>> *N6OL*
>> Saying something doesn't make it true. Belief in something doesn't make it
>> real. And if you have to lie to support a position, that position is not
>> worth supporting.
>> ______________________________________________________________
>> Elecraft mailing list
>> Home: http://mailman.qth.net/mailman/listinfo/elecraft
>> Help: http://mailman.qth.net/mmfaq.htm
>> Post: mailto:[hidden email]
>>
>> 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:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>

Nicklas Johnson

Re: K3S Audio buzz on transmit, especially AM

In reply to this post by Bob McGraw - K4TAX

Before I forget, thank you to everyone who has responded thusfar with ideas
and suggestions. This one is a real head-scratcher, and I appreciate
everyone bouncing ideas around with me.

If the problem is in fact originating with power line neutral distortion,
what, if anything could I actually do about it, beyond what I've already
done in running on battery power? I can't really move my 'shack' in this
case.

I did find the "squeaky wheel" at least. It was the end of one of the
aluminum straps of an antenna mast chimney mount brushing against a copper
ground wire in the wind. A pair of tin snips solved that problem. This
bit was kind of fascinating-- if I held a copper wire against the aluminum
strap, and position the antenna of the KX3 nearby, I could receive some
broadcast AM station on the 51.123 MHz carrier I was transmitting from
inside the house (it's pretty close to a multiple of 810kHz, so if I had to
guess, it was likely KGO I was getting).

I also found the noise gets a hell of a lot louder near the back gutter of
the house (which runs parallel to the power lines that run through the back
yard), though this could just be because the antenna of my KX3 was coupling
to it.

Yet to be determined is whether the noise is a local thing only affecting
reception (e.g., some kind of passive intermod), or if in fact it becomes
part of the signal I'm sending up to the ionosphere. To really figure that
one out, I probably will need to make an actual distant AM contact and ask
someone to tell me how it sounds... this may be no small feat with the way
the sun is behaving lately, but I'll keep trying.

Nick

On Fri, 26 Apr 2019 at 19:18, Bob McGraw K4TAX <[hidden email]> wrote:

> I think Jim's concern, expressed earlier, about power line neutral
> distortion components is valid. And it may be originating in "the big green
> transformer" in the yard.
>
> Bob, K4TAX
>
>
> Sent from my iPhone
>
> > On Apr 26, 2019, at 8:53 PM, Nicklas Johnson <[hidden email]> wrote:
> >
> > Sorry for the additional email, but this is particularly interesting: it
> > occurred to me that I'd never tried the reverse setup, so I put the KX3
> in
> > transmit mode and 0.1W on AM in another room, and set the K3S on receive.
> > And sure enough, the K3S immediately started picking up S40 of buzzing
> > noise. However if I tune the K3S to an AM broadcast station or WWV, no
> > buzz. So either both the K3S and KX3 are being affected on transmit in
> the
> > same way (which seems implausible but not impossible), or possibly
> > something else is going on at my QTH.
> >
> > On the P3, I definitely see the noise when the KX3 is transmitting from
> the
> > other room.
> >
> > Now I wish I had a scope so I could see what the AM carrier generated by
> > the KX3 and K3S looks like so I could tell if this is something that's
> > happening inside the transmitter, or something that is happening because
> of
> > some outside influence mixing powerline noise with the AM carrier. The
> > important thing to me is that the carrier I'm putting out there is
> clean...
> > if there's some local mixing that happens that means I can't listen to my
> > own transmission without a buzz, I can live with that.
> >
> > One kind of curious thing is that there's also a superimposed "squeaky
> > wheel" sound at random intervals detectable when the KX3 is transmitting
> an
> > AM carrier, and not otherwise, and also not when listening to WWV or AM
> > broadcast, which vaguely seems to correlate with how windy it is at any
> > given moment. Could all of this be a "rusty bolt" effect from something
> in
> > the vicinity?
> >
> > Nick
> >
> >
> >
> >> On Fri, 26 Apr 2019 at 18:11, Nicklas Johnson <[hidden email]> wrote:
> >>
> >> A few more data points:
> >>
> >> Changing TX EQ, including cutting the first 4 bands all the way down to
> >> -16 had no effect on the received signal.
> >>
> >> Plugging in some headphones, turning the TX Monitor up all the way, I
> >> don't detect the hum in the TX monitor signal either in TX test mode,
> >> transmitting into a dummy load, or even transmitting into the antenna
> with
> >> very low power. If I turn up the Line In level, I just hear expected
> white
> >> noise on the TX monitor. So at least as far along the path as the TX
> >> monitor, there's no hum or buzz introduced.
> >>
> >> Switching the receiver (a KX3) to USB mode and using one leg of a
> >> buddistick as an antenna so I can walk around, the noise received around
> >> the house and outside is around S4 when transmitting about 100mW into
> the
> >> antenna, though it varies some as I walk around.
> >>
> >> I do have a set of power lines running through my back yard, and where I
> >> live in San Mateo, you're always near somebody's wiring for something,
> >> unfortunately... my neighbor's south wall is possibly as far as 8 feet
> away
> >> from my north wall, etc.
> >>
> >> It looks like two phases running along the top, then a transformer to
> two
> >> phases and a neutral along the bottom, to which people's houses are
> >> connected.
> >>
> >> We also have underground utilities on our street, including a big green
> >> transformer that sits in the corner of our front lawn.
> >>
> >> I think the next test will be to take the K3S and the KX3 some distance
> >> away from all of these things and see if the hum goes away, and if it
> does,
> >> then figure out what thing the K3S needs to get away from in particular.
> >> If it's the powerlines in my back yard or the transformer in my front
> yard,
> >> then that'll be a difficult problem.
> >>
> >> Nick
> >>
> >>
> >>
> >> On Fri, 26 Apr 2019 at 17:28, Bob McGraw K4TAX <[hidden email]>
> >> wrote:
> >>
> >>> Yes but the EQ is in the digital path. The EQ should be done there,
> >>> preferably after the MIC input. The AM BW does not attenuate the end
> like
> >>> the SSB filter.
> >>>
> >>> I suggest -16 dB on the first 3 bands.
> >>>
> >>> Bob, K4TAX
> >>>
> >>>
> >>> Sent from my iPhone
> >>>
> >>>> On Apr 26, 2019, at 6:38 PM, Nicklas Johnson <[hidden email]> wrote:
> >>>>
> >>>> Flat, except I turned the first one down a few notches, which doesn't
> >>>> really do much in my case because both the microphone and mixer that I
> >>> use
> >>>> (when they're actually connected) roll off below 150 and 80 Hz
> >>>> respectively. It had previously been suggested to me that rolling off
> >>> low
> >>>> frequency cruft is a good idea for AM and SSB.
> >>>>
> >>>> Nick
> >>>>
> >>>>> On Fri, 26 Apr 2019 at 15:57, Bob McGraw K4TAX <[hidden email]>
> >>> wrote:
> >>>>>
> >>>>> I recall commenting earlier. What TX EQ values are being used for
> AM.
> >>> ?
> >>>>>
> >>>>> Bob, K4TAX
> >>>>>
> >>>>>
> >>>>> Sent from my iPhone
> >>>>>
> >>>>>> On Apr 26, 2019, at 5:48 PM, Nicklas Johnson <[hidden email]> wrote:
> >>>>>>
> >>>>>> My desk in this case sits adjacent a wall, and there's only a shower
> >>> on
> >>>>> the
> >>>>>> other side of that wall. I did turn off everything in the vicinity
> of
> >>>>> the
> >>>>>> desk and all the lights in the room (I've in fact heard a very
> similar
> >>>>> hum
> >>>>>> from the switching power supply for my mixer, and my first thought
> >>> was it
> >>>>>> was this that was being picked up), but I didn't turn off the
> >>> computer on
> >>>>>> the other side of the room. In this case it will be easier to move
> >>> the
> >>>>> rig
> >>>>>> outdoors with a battery than it will be to turn that computer off
> for
> >>> the
> >>>>>> moment. It would have to be an impressively/obnoxiously strong
> >>> magnetic
> >>>>>> field from that side of the room to influence the transformers
> inside
> >>> the
> >>>>>> rig 8 feet away, but it's worth trying and simple enough to rule it
> >>> out.
> >>>>>>
> >>>>>> Nick
> >>>>>>
> >>>>>>> On Fri, 26 Apr 2019 at 14:51, Don Wilhelm <[hidden email]>
> >>>>> wrote:
> >>>>>>>
> >>>>>>> In addition to operating from a battery isolated from the solar
> >>> system,
> >>>>>>> I would recommend that you do a quick test - remove all cables from
> >>> the
> >>>>>>> K3S except the power cable and a coax to a dummy load. Power down
> >>> all
> >>>>>>> power supplies in your station, including any desk lamps.
> >>>>>>> Go into Transmit by tapping the XMIT button.
> >>>>>>> Is the hum still present? If not, then start connecting things to
> >>> your
> >>>>>>> K3S one at a time, doing the same test after each thing connected.
> >>>>>>>
> >>>>>>> Of course, if the hum is present with nothing connected, contact
> >>>>>>> [hidden email] - but I cannot imagine a hum with harmonics
> of
> >>> 60
> >>>>>>> Hz being induced if you take away all the 60 Hz operated sources in
> >>> the
> >>>>>>> area.
> >>>>>>>
> >>>>>>> 73,
> >>>>>>> Don W3FPR
> >>>>>>>
> >>>>>>> --
> >>>>>> *N6OL*
> >>>>>> Saying something doesn't make it true. Belief in something doesn't
> >>> make
> >>>>> it
> >>>>>> real. And if you have to lie to support a position, that position is
> >>> not
> >>>>>> worth supporting.
> >>>>>> ______________________________________________________________
> >>>>>> Elecraft mailing list
> >>>>>> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> >>>>>> Help: http://mailman.qth.net/mmfaq.htm
> >>>>>> Post: mailto:[hidden email]
> >>>>>>
> >>>>>> This list hosted by: http://www.qsl.net
> >>>>>> Please help support this email list: http://www.qsl.net/donate.html
> >>>>>>
> >>>>>
> >>>>>
> >>>>
> >>>> --
> >>>> *N6OL*
> >>>> Saying something doesn't make it true. Belief in something doesn't
> >>> make it
> >>>> real. And if you have to lie to support a position, that position is
> not
> >>>> worth supporting.
> >>>> ______________________________________________________________
> >>>> Elecraft mailing list
> >>>> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> >>>> Help: http://mailman.qth.net/mmfaq.htm
> >>>> Post: mailto:[hidden email]
> >>>>
> >>>> This list hosted by: http://www.qsl.net
> >>>> Please help support this email list: http://www.qsl.net/donate.html
> >>>>
> >>>
> >>>
> >>>
> >>
> >> --
> >> *N6OL*
> >> Saying something doesn't make it true. Belief in something doesn't make
> >> it real. And if you have to lie to support a position, that position is
> not
> >> worth supporting.
> >>
> >
> >
> > --
> > *N6OL*
> > Saying something doesn't make it true. Belief in something doesn't make
> it
> > real. And if you have to lie to support a position, that position is not
> > worth supporting.
> > ______________________________________________________________
> > Elecraft mailing list
> > Home: http://mailman.qth.net/mailman/listinfo/elecraft
> > Help: http://mailman.qth.net/mmfaq.htm
> > Post: mailto:[hidden email]
> >
> > This list hosted by: http://www.qsl.net
> > Please help support this email list: http://www.qsl.net/donate.html
> >
>
>
>

Frank Krozel

Re: K3S Audio buzz on transmit, especially AM

Try switching to a linear supply?

Sincerely, Frank Krozel t: 1-630-924-1600 [hidden email]
BSEE, AASEET, FCC Lic.# PG-18-19178, KG9H
Electronic Instrument Associates - Central, Inc. ...since 1971
w: www.electronicinstrument.com d/l our linecard at http://www.electronicinstrument.com/lc.pdf

> On Apr 26, 2019, at 9:46 PM, Nicklas Johnson <[hidden email]> wrote:
>
> Before I forget, thank you to everyone who has responded thusfar with ideas
> and suggestions. This one is a real head-scratcher, and I appreciate
> everyone bouncing ideas around with me.
>
> If the problem is in fact originating with power line neutral distortion,
> what, if anything could I actually do about it, beyond what I've already
> done in running on battery power? I can't really move my 'shack' in this
> case.
>
> I did find the "squeaky wheel" at least. It was the end of one of the
> aluminum straps of an antenna mast chimney mount brushing against a copper
> ground wire in the wind. A pair of tin snips solved that problem. This
> bit was kind of fascinating-- if I held a copper wire against the aluminum
> strap, and position the antenna of the KX3 nearby, I could receive some
> broadcast AM station on the 51.123 MHz carrier I was transmitting from
> inside the house (it's pretty close to a multiple of 810kHz, so if I had to
> guess, it was likely KGO I was getting).
>
> I also found the noise gets a hell of a lot louder near the back gutter of
> the house (which runs parallel to the power lines that run through the back
> yard), though this could just be because the antenna of my KX3 was coupling
> to it.
>
> Yet to be determined is whether the noise is a local thing only affecting
> reception (e.g., some kind of passive intermod), or if in fact it becomes
> part of the signal I'm sending up to the ionosphere. To really figure that
> one out, I probably will need to make an actual distant AM contact and ask
> someone to tell me how it sounds... this may be no small feat with the way
> the sun is behaving lately, but I'll keep trying.
>
> Nick
>
>> On Fri, 26 Apr 2019 at 19:18, Bob McGraw K4TAX <[hidden email]> wrote:
>>
>> I think Jim's concern, expressed earlier, about power line neutral
>> distortion components is valid. And it may be originating in "the big green
>> transformer" in the yard.
>>
>> Bob, K4TAX
>>
>>
>> Sent from my iPhone
>>
>>> On Apr 26, 2019, at 8:53 PM, Nicklas Johnson <[hidden email]> wrote:
>>>
>>> Sorry for the additional email, but this is particularly interesting: it
>>> occurred to me that I'd never tried the reverse setup, so I put the KX3
>> in
>>> transmit mode and 0.1W on AM in another room, and set the K3S on receive.
>>> And sure enough, the K3S immediately started picking up S40 of buzzing
>>> noise. However if I tune the K3S to an AM broadcast station or WWV, no
>>> buzz. So either both the K3S and KX3 are being affected on transmit in
>> the
>>> same way (which seems implausible but not impossible), or possibly
>>> something else is going on at my QTH.
>>>
>>> On the P3, I definitely see the noise when the KX3 is transmitting from
>> the
>>> other room.
>>>
>>> Now I wish I had a scope so I could see what the AM carrier generated by
>>> the KX3 and K3S looks like so I could tell if this is something that's
>>> happening inside the transmitter, or something that is happening because
>> of
>>> some outside influence mixing powerline noise with the AM carrier. The
>>> important thing to me is that the carrier I'm putting out there is
>> clean...
>>> if there's some local mixing that happens that means I can't listen to my
>>> own transmission without a buzz, I can live with that.
>>>
>>> One kind of curious thing is that there's also a superimposed "squeaky
>>> wheel" sound at random intervals detectable when the KX3 is transmitting
>> an
>>> AM carrier, and not otherwise, and also not when listening to WWV or AM
>>> broadcast, which vaguely seems to correlate with how windy it is at any
>>> given moment. Could all of this be a "rusty bolt" effect from something
>> in
>>> the vicinity?
>>>
>>> Nick
>>>
>>>
>>>
>>>> On Fri, 26 Apr 2019 at 18:11, Nicklas Johnson <[hidden email]> wrote:
>>>>
>>>> A few more data points:
>>>>
>>>> Changing TX EQ, including cutting the first 4 bands all the way down to
>>>> -16 had no effect on the received signal.
>>>>
>>>> Plugging in some headphones, turning the TX Monitor up all the way, I
>>>> don't detect the hum in the TX monitor signal either in TX test mode,
>>>> transmitting into a dummy load, or even transmitting into the antenna
>> with
>>>> very low power. If I turn up the Line In level, I just hear expected
>> white
>>>> noise on the TX monitor. So at least as far along the path as the TX
>>>> monitor, there's no hum or buzz introduced.
>>>>
>>>> Switching the receiver (a KX3) to USB mode and using one leg of a
>>>> buddistick as an antenna so I can walk around, the noise received around
>>>> the house and outside is around S4 when transmitting about 100mW into
>> the
>>>> antenna, though it varies some as I walk around.
>>>>
>>>> I do have a set of power lines running through my back yard, and where I
>>>> live in San Mateo, you're always near somebody's wiring for something,
>>>> unfortunately... my neighbor's south wall is possibly as far as 8 feet
>> away
>>>> from my north wall, etc.
>>>>
>>>> It looks like two phases running along the top, then a transformer to
>> two
>>>> phases and a neutral along the bottom, to which people's houses are
>>>> connected.
>>>>
>>>> We also have underground utilities on our street, including a big green
>>>> transformer that sits in the corner of our front lawn.
>>>>
>>>> I think the next test will be to take the K3S and the KX3 some distance
>>>> away from all of these things and see if the hum goes away, and if it
>> does,
>>>> then figure out what thing the K3S needs to get away from in particular.
>>>> If it's the powerlines in my back yard or the transformer in my front
>> yard,
>>>> then that'll be a difficult problem.
>>>>
>>>> Nick
>>>>
>>>>
>>>>
>>>> On Fri, 26 Apr 2019 at 17:28, Bob McGraw K4TAX <[hidden email]>
>>>> wrote:
>>>>
>>>>> Yes but the EQ is in the digital path. The EQ should be done there,
>>>>> preferably after the MIC input. The AM BW does not attenuate the end
>> like
>>>>> the SSB filter.
>>>>>
>>>>> I suggest -16 dB on the first 3 bands.
>>>>>
>>>>> Bob, K4TAX
>>>>>
>>>>>
>>>>> Sent from my iPhone
>>>>>
>>>>>> On Apr 26, 2019, at 6:38 PM, Nicklas Johnson <[hidden email]> wrote:
>>>>>>
>>>>>> Flat, except I turned the first one down a few notches, which doesn't
>>>>>> really do much in my case because both the microphone and mixer that I
>>>>> use
>>>>>> (when they're actually connected) roll off below 150 and 80 Hz
>>>>>> respectively. It had previously been suggested to me that rolling off
>>>>> low
>>>>>> frequency cruft is a good idea for AM and SSB.
>>>>>>
>>>>>> Nick
>>>>>>
>>>>>>> On Fri, 26 Apr 2019 at 15:57, Bob McGraw K4TAX <[hidden email]>
>>>>> wrote:
>>>>>>>
>>>>>>> I recall commenting earlier. What TX EQ values are being used for
>> AM.
>>>>> ?
>>>>>>>
>>>>>>> Bob, K4TAX
>>>>>>>
>>>>>>>
>>>>>>> Sent from my iPhone
>>>>>>>
>>>>>>>> On Apr 26, 2019, at 5:48 PM, Nicklas Johnson <[hidden email]> wrote:
>>>>>>>>
>>>>>>>> My desk in this case sits adjacent a wall, and there's only a shower
>>>>> on
>>>>>>> the
>>>>>>>> other side of that wall. I did turn off everything in the vicinity
>> of
>>>>>>> the
>>>>>>>> desk and all the lights in the room (I've in fact heard a very
>> similar
>>>>>>> hum
>>>>>>>> from the switching power supply for my mixer, and my first thought
>>>>> was it
>>>>>>>> was this that was being picked up), but I didn't turn off the
>>>>> computer on
>>>>>>>> the other side of the room. In this case it will be easier to move
>>>>> the
>>>>>>> rig
>>>>>>>> outdoors with a battery than it will be to turn that computer off
>> for
>>>>> the
>>>>>>>> moment. It would have to be an impressively/obnoxiously strong
>>>>> magnetic
>>>>>>>> field from that side of the room to influence the transformers
>> inside
>>>>> the
>>>>>>>> rig 8 feet away, but it's worth trying and simple enough to rule it
>>>>> out.
>>>>>>>>
>>>>>>>> Nick
>>>>>>>>
>>>>>>>>> On Fri, 26 Apr 2019 at 14:51, Don Wilhelm <[hidden email]>
>>>>>>> wrote:
>>>>>>>>>
>>>>>>>>> In addition to operating from a battery isolated from the solar
>>>>> system,
>>>>>>>>> I would recommend that you do a quick test - remove all cables from
>>>>> the
>>>>>>>>> K3S except the power cable and a coax to a dummy load. Power down
>>>>> all
>>>>>>>>> power supplies in your station, including any desk lamps.
>>>>>>>>> Go into Transmit by tapping the XMIT button.
>>>>>>>>> Is the hum still present? If not, then start connecting things to
>>>>> your
>>>>>>>>> K3S one at a time, doing the same test after each thing connected.
>>>>>>>>>
>>>>>>>>> Of course, if the hum is present with nothing connected, contact
>>>>>>>>> [hidden email] - but I cannot imagine a hum with harmonics
>> of
>>>>> 60
>>>>>>>>> Hz being induced if you take away all the 60 Hz operated sources in
>>>>> the
>>>>>>>>> area.
>>>>>>>>>
>>>>>>>>> 73,
>>>>>>>>> Don W3FPR
>>>>>>>>>
>>>>>>>>> --
>>>>>>>> *N6OL*
>>>>>>>> Saying something doesn't make it true. Belief in something doesn't
>>>>> make
>>>>>>> it
>>>>>>>> real. And if you have to lie to support a position, that position is
>>>>> not
>>>>>>>> worth supporting.
>>>>>>>> ______________________________________________________________
>>>>>>>> Elecraft mailing list
>>>>>>>> Home: http://mailman.qth.net/mailman/listinfo/elecraft
>>>>>>>> Help: http://mailman.qth.net/mmfaq.htm
>>>>>>>> Post: mailto:[hidden email]
>>>>>>>>
>>>>>>>> This list hosted by: http://www.qsl.net
>>>>>>>> Please help support this email list: http://www.qsl.net/donate.html
>>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>
>>>>>> --
>>>>>> *N6OL*
>>>>>> Saying something doesn't make it true. Belief in something doesn't
>>>>> make it
>>>>>> real. And if you have to lie to support a position, that position is
>> not
>>>>>> worth supporting.
>>>>>> ______________________________________________________________
>>>>>> Elecraft mailing list
>>>>>> Home: http://mailman.qth.net/mailman/listinfo/elecraft
>>>>>> Help: http://mailman.qth.net/mmfaq.htm
>>>>>> Post: mailto:[hidden email]
>>>>>>
>>>>>> This list hosted by: http://www.qsl.net
>>>>>> Please help support this email list: http://www.qsl.net/donate.html
>>>>>>
>>>>>
>>>>>
>>>>>
>>>>
>>>> --
>>>> *N6OL*
>>>> Saying something doesn't make it true. Belief in something doesn't make
>>>> it real. And if you have to lie to support a position, that position is
>> not
>>>> worth supporting.
>>>>
>>>
>>>
>>> --
>>> *N6OL*
>>> Saying something doesn't make it true. Belief in something doesn't make
>> it
>>> real. And if you have to lie to support a position, that position is not
>>> worth supporting.
>>> ______________________________________________________________
>>> Elecraft mailing list
>>> Home: http://mailman.qth.net/mailman/listinfo/elecraft
>>> Help: http://mailman.qth.net/mmfaq.htm
>>> Post: mailto:[hidden email]
>>>
>>> This list hosted by: http://www.qsl.net
>>> Please help support this email list: http://www.qsl.net/donate.html
>>>
>>
>>
>>
>
> --
> *N6OL*
> Saying something doesn't make it true. Belief in something doesn't make it
> real. And if you have to lie to support a position, that position is not
> worth supporting.
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html

Jim Brown-10

Re: K3S Audio buzz on transmit, especially AM

In reply to this post by Nicklas Johnson

On 4/26/2019 6:11 PM, Nicklas Johnson wrote:
> Plugging in some headphones, turning the TX Monitor up all the way, I don't
> detect the hum in the TX monitor signal either in TX test mode,
> transmitting into a dummy load, or even transmitting into the antenna with
> very low power. If I turn up the Line In level, I just hear expected white
> noise on the TX monitor. So at least as far along the path as the TX
> monitor, there's no hum or buzz introduced.

I'm confused, Nick. Under what conditions DO you hear the buzz? Antenna
connected to the K3S?

> Switching the receiver (a KX3) to USB mode and using one leg of a
> buddistick as an antenna so I can walk around, the noise received around
> the house and outside is around S4 when transmitting about 100mW into the
> antenna, though it varies some as I walk around.

I'm more confused. When you have been listening to your signal and
hearing the buzz, HOW were you listening to it? Were you listening on
the KX3? If you transmit 5-10W into a dummy load you should be able to
hear your signal in a KX3 sitting next to it with NO antenna.

Does the buzz only happen when you're listening on the KX3 and there's
an antenna connected to the K3S? That brings up the possibility of
passive intermod. We'll talk about that after we've gotten the symptoms
straight.

73, Jim K9YC

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Jim Brown-10

Re: K3S Audio buzz on transmit, especially AM

In reply to this post by Frank Krozel

On 4/26/2019 7:48 PM, Frank Krozel wrote:
> Try switching to a linear supply?

No, ALL power supplies with cap input filter have harmonics. But the
problem is FAR, FAR larger than equipment in the shack.

Nick -- what kind of mic do you use with your rig? Is it an electret or
a dynamic? Another way of asking -- do you have turn on bias to make it
work? Does the buzz get worse with the mic plugged in? Does turning up
the mic gain make it louder?

73, Jim

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donovanf

Re: K3S Audio buzz on transmit, especially AM

In reply to this post by Nicklas Johnson

Hi Nick,

Since there are many unknowns and concerns about the EMI and
magnetic environment at your home QTH, it might be revealing
to repeat your basic tests (battery and dummy load) at a friend's
QTH. Maybe you also have a friend who owns a K3 or K3S.

Forget about resetting your transceiver. Your varied descriptions
point to EMI or one (or more) strong magnetic fields as the source
of your difficulties.

How far is the "big green transformer" from your ham shack?

Have you ever attempted to perform this type of troubleshooting
in the past? Y our emails leave the impression that your approach
isn't very methodical. A friend with troubleshooting experience
could be of great help in getting you organized for a successful result.

73
Frank
W3LPL

----- Original Message -----

From: "Nicklas Johnson" <[hidden email]>
To: "elecraft" <[hidden email]>
Sent: Saturday, April 27, 2019 1:53:27 AM
Subject: Re: [Elecraft] K3S Audio buzz on transmit, especially AM

Sorry for the additional email, but this is particularly interesting: it
occurred to me that I'd never tried the reverse setup, so I put the KX3 in
transmit mode and 0.1W on AM in another room, and set the K3S on receive.
And sure enough, the K3S immediately started picking up S40 of buzzing
noise. However if I tune the K3S to an AM broadcast station or WWV, no
buzz. So either both the K3S and KX3 are being affected on transmit in the
same way (which seems implausible but not impossible), or possibly
something else is going on at my QTH.

On the P3, I definitely see the noise when the KX3 is transmitting from the
other room.

Now I wish I had a scope so I could see what the AM carrier generated by
the KX3 and K3S looks like so I could tell if this is something that's
happening inside the transmitter, or something that is happening because of
some outside influence mixing powerline noise with the AM carrier. The
important thing to me is that the carrier I'm putting out there is clean...
if there's some local mixing that happens that means I can't listen to my
own transmission without a buzz, I can live with that.

One kind of curious thing is that there's also a superimposed "squeaky
wheel" sound at random intervals detectable when the KX3 is transmitting an
AM carrier, and not otherwise, and also not when listening to WWV or AM
broadcast, which vaguely seems to correlate with how windy it is at any
given moment. Could all of this be a "rusty bolt" effect from something in
the vicinity?

Nick

On Fri, 26 Apr 2019 at 18:11, Nicklas Johnson <[hidden email]> wrote:

--
*N6OL*
Saying something doesn't make it true. Belief in something doesn't make it
real. And if you have to lie to support a position, that position is not
worth supporting.
______________________________________________________________
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Jim Brown-10

Re: K3S Audio buzz on transmit, especially AM

On 4/26/2019 10:44 PM, [hidden email] wrote:
> Y our emails leave the impression that your approach
> isn't very methodical.

Yes, but that lack of methodical troubleshooting is the result of most
hams being weak on the fundamentals of fields and passive IM, instead
seeing problems in the light of RFI and mythical concepts like "ground
loops."

The two causes I've come around to smelling in this problem are passive
IM (which Frank reminded me of) and power-related fields. And Frank's
advice is right on.

73, Jim K9YC

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Nicklas Johnson

Re: K3S Audio buzz on transmit, especially AM

I don't think that "collecting data" and "process of elimination" are
particularly ANTI-methodical either. But the fact is that most people will
never encounter this kind of problem and don't spend their days practicing
how to troubleshoot it, so they seek advice from people who do have
experience. Thus this email thread, which began with my thinking I'd
developed an audio fault in the rig and seeking advice, but successive
tests have pointed in other directions.

To answer Jim's earlier question, yes, it does appear that transmitting an
unmodulated AM carrier from the K3S into anything resembling an antenna
yields a buzz on the KX3 receiver (and vice-versa). The buzz is NOT
audible when listening to the K3S's own TX monitor.

And to answer Frank's question, the PG&E transformer in our front yard for
the underground utilities is approximately 30 horizontal feet over and 6
vertical feet down from the station. The distance to the utilities that
run through the back of our lot is approximately 60 feet.

I spent the morning reviewing (again) materials on grounding and bonding
over my morning coffee to see if there's something important I missed, and
I also found by repeating it that an earlier test I'd done had given me a
misleading/contradictory result-- transmitting into a dummy load
immediately adjacent the KX3 receiving it produces a nice, clean signal. I
was misled before by the KX3 picking up a different buzz (probably off a
wall wart) in the shack when performing this test earlier. (It also helped
in this case to put the KX3 into CW mode to detect the unmodulated AM
carrier.)

FWIW, this morning I also disconnected the bonding between the station's
ground rod and the house's utility power and also disconnected the DTV
antenna run into the house (which shares the same coax grounding/surge
protection bus outside, but of course could find another path to ground
over the coax shield via either one of the TV receivers). Doing so
eliminated any *direct * connection with the utility power, as I'm still
running purely on battery power. This had NO effect on the received buzz.

At this point I'm pretty sure this is an environmental issue and not a
problem with either rig, so it's probably not appropriate for me to
continue to pester the list about it. Thank you again to everyone who
offered suggestions and advice.

But for posterity, and in case anyone comes along searching the list while
debugging a similar problem, here's a list of all the other things that I
tried to isolate the problem, none of which had any effect:

- Complete disconnection of all other inputs and outputs on the K3S
other than the antenna.
- Turning off all nearby power supplies.
- Setting the input to any other selection (front panel, rear panel,
line in)
- Setting the line input level to 0, verifying that front and rear panel
gains were set to "low"
- Running solely on battery power without the solar charge controller
- TX EQ settings- cutting the low end completely
- Taking the receiver outdoors, away from power supplies
- Trying a different transmit antenna (ie, making sure I wasn't having
problems with a damaged dipole having the house neutral wiring as one leg)
- Temporarily disconnecting the station ground
- Temporarily disconnecting the utility bonding from the station's
ground rod
- Reversing the direction: transmitting with the KX3 into a portable
antenna and receiving with the K3S also produced a much more significant
buzz

What DID yield some useful data:

- Transmitting into a dummy load *while* turning off all nearby power
supplies and lights with the KX3 immediately adjacent the dummy load: nice,
pristine signal
- Checking the TX monitor on the K3S: only white noise with the line
input and the monitor output turned to maximum while transmitting.

What I have yet to do, and will require some more time and effort to
organize and implement:

- Going portable or to another QTH to test again
- Getting a signal report from a distant station to see if this is a
local reception problem, or something actually getting into the transmitted
signal.

Nick

On Sat, 27 Apr 2019 at 01:19, Jim Brown <[hidden email]> wrote:

> On 4/26/2019 10:44 PM, [hidden email] wrote:
> > Y our emails leave the impression that your approach
> > isn't very methodical.
>
> Yes, but that lack of methodical troubleshooting is the result of most
> hams being weak on the fundamentals of fields and passive IM, instead
> seeing problems in the light of RFI and mythical concepts like "ground
> loops."
>
> The two causes I've come around to smelling in this problem are passive
> IM (which Frank reminded me of) and power-related fields. And Frank's
> advice is right on.
>
> 73, Jim K9YC
>
>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>

Jim Brown-10

Re: K3S Audio buzz on transmit, especially AM

On 4/27/2019 11:31 AM, Nicklas Johnson wrote:
> To answer Jim's earlier question, yes, it does appear that transmitting an
> unmodulated AM carrier from the K3S into anything resembling an antenna
> yields a buzz on the KX3 receiver (and vice-versa). The buzz is NOT
> audible when listening to the K3S's own TX monitor.

OK. Try this test. Running from a battery, no connection to anything
grounded, TX into an antenna and listen on the KX3 running on internal
batteries, also not connected to anything grounded. Do you hear buzz? If
not, walk around until you do. If you do, walk around until it's
loudest. What this test is doing is probing for some source of passive
intermod. It could be in your own home, or it could be somewhere else.

And try this test. Transmit into an antenna and have someone listen to
your signal. I see that you're only 36 miles from me, so perhaps I could
do that on 75M if you have a suitable antenna.

I haven't seen an answer for my question about DC voltage under RX and
TX conditions.

73, Jim K9YC

______________________________________________________________
Elecraft mailing list
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Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html

Rick WA6NHC-2

Re: K3S Audio buzz on transmit, especially AM

In reply to this post by Nicklas Johnson

What they are saying is that it is best to break things down into
logical clear steps, isolating as much as possible to prove or eliminate
cause and effect. The issue are that some folks don't know enough to do
this and some have issues trying to be logical; running in circles while
others often seek the easy way(s) out. No slur is meant or intended,
people have different abilities or we wouldn't need groups like this.

This is all best done while the XYL is at the spa or otherwise
unavailable for a few hours. ;-)

Here is one example for your situation:

A critical and valid test to find the source of your radio problem is to
run the radio on battery (no solar, no other wiring including ground)
into a dummy load (completely isolated from everything, including any
metal table that might be in use) with the house mains (and any
outbuildings) turned completely OFF. Set up the test receiver in the
same manner (nothing but different battery for power and another dummy
load).

This is to determine if it's the radio or the home environment (no stray
induction). If everything is clean, it's probably not the radio but to
make sure...

The second portion of that test would be to repeat on different bands or
frequencies within the band to eliminate 'fundamental overload' or
unexpected mixing of the receiver (which should also be on a dummy load,
proximity is likely enough to hear the signal). Is it band related or
single band, on one frequency only or all? At only certain output power
levels (bad internal amp? A 100 watt K3 has a series of three amps)?
If the radio is clean, skip the next step.

The third step (if the problem still exists) is to provide physical
isolation of the receiver (another room even if both are on dummy loads)
to note any changes (overload or coupling is no longer likely). If the
problem remains, it's a radio issue (don't discount a receiver issue so
you can confirm the issue with a second receiver).

Then based on these results, if it's all clean, (therefore not a radio
issue so more testing is required to find the actual cause) one then
determines a potential cause as you re-power the house (breaker by
breaker). In other words, when does it return?

In the best case, flipping only one breaker on, testing, turning that
breaker off and moving to the next breaker; then bringing multiple
breakers on in combinations (interaction of home devices?). At which
point/s does the issue return? Single breaker means examine everything
powered on that circuit, mixed breakers is much more of a challenge to
find the cause. Recall that house wiring often appears 'random' so it
may be a challenge to find what each circuit powers.

If the problem doesn't return with turning on all the breakers, the
search continues.

Note changes as you reconnect to the rest of the world (add antennas,
control cables, etc) to your station. Through more testing, at which
point does the issue return?

Then reset all the clocks in the house as you ponder the results.

With an antenna connected, this series of tests also gives you a good
baseline for RF noise reduction if the home generates noise (it's
guaranteed that it will).

In your case, just for giggles, make SURE that ALL the tmp connectors in
the K3(s) are properly connected as well (re-seat them) and re-tighten
all screws and bolts as well (Murphy lives). While it's opened up, make
sure no case paint is in the way of any bonding too, no corrosion,
roaming parts etc. and look for obvious failures (disconnected wires,
frays or pinched wire all without the smell of escaped smoke).

And lastly, a complete reset (groan) is an option, sometimes things are
not what they show to be or are expected to be (stuck bits, EEPROM
belches...). Made when the radio is functioning correctly, you DO have
a current backup of settings to use, no? If not, you manually make what
changes are required (MANY of them, hence the groan) THEN make a backup.

Now if there is a need to call for further assistance (Elecraft help
line, your Elmer or here), one has (dis)proven some of the possibilities
to present the issue.

While others may disagree in this content, this is but one path to follow.

GL,
Rick nhc

On 4/27/2019 11:31 AM, Nicklas Johnson wrote:

> I don't think that "collecting data" and "process of elimination" are
> particularly ANTI-methodical either. But the fact is that most people will
> never encounter this kind of problem and don't spend their days practicing
> how to troubleshoot it, so they seek advice from people who do have
> experience. Thus this email thread, which began with my thinking I'd
> developed an audio fault in the rig and seeking advice, but successive
> tests have pointed in other directions.
>
> To answer Jim's earlier question, yes, it does appear that transmitting an
> unmodulated AM carrier from the K3S into anything resembling an antenna
> yields a buzz on the KX3 receiver (and vice-versa). The buzz is NOT
> audible when listening to the K3S's own TX monitor.
>
> And to answer Frank's question, the PG&E transformer in our front yard for
> the underground utilities is approximately 30 horizontal feet over and 6
> vertical feet down from the station. The distance to the utilities that
> run through the back of our lot is approximately 60 feet.
>
> I spent the morning reviewing (again) materials on grounding and bonding
> over my morning coffee to see if there's something important I missed, and
> I also found by repeating it that an earlier test I'd done had given me a
> misleading/contradictory result-- transmitting into a dummy load
> immediately adjacent the KX3 receiving it produces a nice, clean signal. I
> was misled before by the KX3 picking up a different buzz (probably off a
> wall wart) in the shack when performing this test earlier. (It also helped
> in this case to put the KX3 into CW mode to detect the unmodulated AM
> carrier.)
>
> FWIW, this morning I also disconnected the bonding between the station's
> ground rod and the house's utility power and also disconnected the DTV
> antenna run into the house (which shares the same coax grounding/surge
> protection bus outside, but of course could find another path to ground
> over the coax shield via either one of the TV receivers). Doing so
> eliminated any *direct * connection with the utility power, as I'm still
> running purely on battery power. This had NO effect on the received buzz.
>
> At this point I'm pretty sure this is an environmental issue and not a
> problem with either rig, so it's probably not appropriate for me to
> continue to pester the list about it. Thank you again to everyone who
> offered suggestions and advice.
>
> But for posterity, and in case anyone comes along searching the list while
> debugging a similar problem, here's a list of all the other things that I
> tried to isolate the problem, none of which had any effect:
>
> - Complete disconnection of all other inputs and outputs on the K3S
> other than the antenna.
> - Turning off all nearby power supplies.
> - Setting the input to any other selection (front panel, rear panel,
> line in)
> - Setting the line input level to 0, verifying that front and rear panel
> gains were set to "low"
> - Running solely on battery power without the solar charge controller
> - TX EQ settings- cutting the low end completely
> - Taking the receiver outdoors, away from power supplies
> - Trying a different transmit antenna (ie, making sure I wasn't having
> problems with a damaged dipole having the house neutral wiring as one leg)
> - Temporarily disconnecting the station ground
> - Temporarily disconnecting the utility bonding from the station's
> ground rod
> - Reversing the direction: transmitting with the KX3 into a portable
> antenna and receiving with the K3S also produced a much more significant
> buzz
>
> What DID yield some useful data:
>
> - Transmitting into a dummy load *while* turning off all nearby power
> supplies and lights with the KX3 immediately adjacent the dummy load: nice,
> pristine signal
> - Checking the TX monitor on the K3S: only white noise with the line
> input and the monitor output turned to maximum while transmitting.
>
> What I have yet to do, and will require some more time and effort to
> organize and implement:
>
> - Going portable or to another QTH to test again
> - Getting a signal report from a distant station to see if this is a
> local reception problem, or something actually getting into the transmitted
> signal.
>
>
> Nick
>

donovanf

Re: K3S Audio buzz on transmit, especially AM

In reply to this post by Nicklas Johnson

Hi Nick,

You've done a good job organizing your tests and test results.

One more question: how far is your transmitting antenna from
your ham shack and other nearby homes?

Very telling is this comment at the end of your email:
"Transmitting into a dummy load *while* turning off all nearby power
supplies and lights with the KX3 immediately adjacent the dummy load: nice,
pristine signal"

That certainly points to EMC issues in your environment. When you're
ready for additional tests, first go back to your pristine signal case.
Then -- one by one -- turn additional radio accessories and household
on and reconnect them. Repeat your test each time you change
something.

I strongly suspect that you have a common EMI condition in your
ham shack, probably elsewhere in your home and possibly in adjacent
homes known as "RF FLOODING."

What the heck is RF Flooding? When a strong RF signal enters a
non-linear device (semiconductors most commonly, but also ferrites
near saturation) that also carries other signals (most commonly AC
power, but also computer related signals such as Ethernet), the
non-linear device will mix the two signals together and reradiate
them (including harmonics of the RF signal) on the wires connected
to the non-linear device.

Multi-operator and SO2R operator contest stations have experienced
RF Flooding interference for decades, but the problem has become
much worse as semiconductor devices have proliferated. Switching
power supplies are among the worst offenders, especially wall-warts.

If you have a RF flooding problem it will be especially apparent on
the second and third harmonic of your transmitted signal. On the
harmonic frequencies the buzz sidebands may be stronger than the
transmitted harmonic.

So what to do about it? If you don't intend to operate multi-operator
or SO2R contests from your QTH, there's no reason to fix the problem
at all. The buzz sidebands probably don't radiate more than a few
hundred feet from your QTH. In that case its simply been an EMC
learning experience about the consequences of introducing a strong
RF field into a houseful of electronics.

73
Frank
W3LPL

----- Original Message -----

From: "Nicklas Johnson" <[hidden email]>
To: "elecraft" <[hidden email]>
Sent: Saturday, April 27, 2019 6:31:53 PM
Subject: Re: [Elecraft] K3S Audio buzz on transmit, especially AM

I don't think that "collecting data" and "process of elimination" are
particularly ANTI-methodical either. But the fact is that most people will
never encounter this kind of problem and don't spend their days practicing
how to troubleshoot it, so they seek advice from people who do have
experience. Thus this email thread, which began with my thinking I'd
developed an audio fault in the rig and seeking advice, but successive
tests have pointed in other directions.

To answer Jim's earlier question, yes, it does appear that transmitting an
unmodulated AM carrier from the K3S into anything resembling an antenna
yields a buzz on the KX3 receiver (and vice-versa). The buzz is NOT
audible when listening to the K3S's own TX monitor.

And to answer Frank's question, the PG&E transformer in our front yard for
the underground utilities is approximately 30 horizontal feet over and 6
vertical feet down from the station. The distance to the utilities that
run through the back of our lot is approximately 60 feet.

I spent the morning reviewing (again) materials on grounding and bonding
over my morning coffee to see if there's something important I missed, and
I also found by repeating it that an earlier test I'd done had given me a
misleading/contradictory result-- transmitting into a dummy load
immediately adjacent the KX3 receiving it produces a nice, clean signal. I
was misled before by the KX3 picking up a different buzz (probably off a
wall wart) in the shack when performing this test earlier. (It also helped
in this case to put the KX3 into CW mode to detect the unmodulated AM
carrier.)

FWIW, this morning I also disconnected the bonding between the station's
ground rod and the house's utility power and also disconnected the DTV
antenna run into the house (which shares the same coax grounding/surge
protection bus outside, but of course could find another path to ground
over the coax shield via either one of the TV receivers). Doing so
eliminated any *direct * connection with the utility power, as I'm still
running purely on battery power. This had NO effect on the received buzz.

At this point I'm pretty sure this is an environmental issue and not a
problem with either rig, so it's probably not appropriate for me to
continue to pester the list about it. Thank you again to everyone who
offered suggestions and advice.

But for posterity, and in case anyone comes along searching the list while
debugging a similar problem, here's a list of all the other things that I
tried to isolate the problem, none of which had any effect:

- Complete disconnection of all other inputs and outputs on the K3S
other than the antenna.
- Turning off all nearby power supplies.
- Setting the input to any other selection (front panel, rear panel,
line in)
- Setting the line input level to 0, verifying that front and rear panel
gains were set to "low"
- Running solely on battery power without the solar charge controller
- TX EQ settings- cutting the low end completely
- Taking the receiver outdoors, away from power supplies
- Trying a different transmit antenna (ie, making sure I wasn't having
problems with a damaged dipole having the house neutral wiring as one leg)
- Temporarily disconnecting the station ground
- Temporarily disconnecting the utility bonding from the station's
ground rod
- Reversing the direction: transmitting with the KX3 into a portable
antenna and receiving with the K3S also produced a much more significant
buzz

What DID yield some useful data:

- Transmitting into a dummy load *while* turning off all nearby power
supplies and lights with the KX3 immediately adjacent the dummy load: nice,
pristine signal
- Checking the TX monitor on the K3S: only white noise with the line
input and the monitor output turned to maximum while transmitting.

What I have yet to do, and will require some more time and effort to
organize and implement:

- Going portable or to another QTH to test again
- Getting a signal report from a distant station to see if this is a
local reception problem, or something actually getting into the transmitted
signal.

Nick

On Sat, 27 Apr 2019 at 01:19, Jim Brown <[hidden email]> wrote:

k6dgw

Re: K3S Audio buzz on transmit, especially AM

In reply to this post by Rick WA6NHC-2

Ahh indeed. Several hours at W7RN with a new router trying random
things was less than productive. A more structured, several step effort
at home yielded the solution, which was primarily router pilot error.

73,
Fred ["Skip"] K6DGW
Sparks NV DM09dn
Washoe County

On 4/27/2019 1:02 PM, Rick WA6NHC wrote:

> What they are saying is that it is best to break things down into
> logical clear steps, isolating as much as possible to prove or
> eliminate cause and effect. The issue are that some folks don't know
> enough to do this and some have issues trying to be logical; running
> in circles while others often seek the easy way(s) out. No slur is
> meant or intended, people have different abilities or we wouldn't need
> groups like this.
>
> This is all best done while the XYL is at the spa or otherwise
> unavailable for a few hours. ;-)
>