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K3 weird noise generation...??

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Phil Hystad-3

K3 weird noise generation...??

I came home from work and turned on the K3 and the P3 and then switched to the CW zone of the 40 meter band. The VFO was about 7.009 as left from my last visit yesterday. I turned the VFO up just a tiny bit and this strong, like S9+ broadband noise came through. Funny because I remember looking at the spectrum of the P3 and I did not see anything there.

A long story short. I discovered that this noise was being generated by the K3. I had checked the band with my Icom 756 Pro III and nothing was there except lots of CW signals. I tuned the Pro III around the same spots as the K3. So, I rotated the VFO slow up frequency from 7.009 and at 7.00945 the noise started and continued up to about 7015.5. Now, on the spectrum this was a good 50 dB over and above my normal noise floor (sorry, not sure if I am using the right terminology) and it was the same across the entire spectrum which by the way was set wider then this frequency range of 7009 to 7015. And, all other CW signals disappeared and many of them were stronger then this noise level.

So, if I turned the VFO just past the upper threshold of 7015.5, the noise disappears entirely and there is nothing but normal display of CW signals on the spectrum.

I then decided to power off the K3 and P3. Powered back up and this weird noise phenomena disappeared. Now, the K3 and P3 is acting normal.

Anyone see anything like this?

73, phil, K7PEH
K3 Serial #3799
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Matt Zilmer

Re: K3 weird noise generation...??

Next time you see something like this, take a look at the VCO control
voltage (PLL1 or PLL2) using the DISP meter function. If the K3 goes
out of lock, it puts out all sorts of garbage audio and the PLL (VCO)
voltage moves around randomly.

I've had this happen on 5 MHz when working with certain MARS
frequencies. I've found it *only* happens when a command sequence
comes from RMS Express - something that puts the K3 in a weird mode
(probably commands too close back to back). I haven't determined what
the command sequence is yet.

If this is what's happening, you probably should discuss it with
Elecraft support.

GL & 73,
matt W6NIA

On Thu, 30 Dec 2010 16:41:23 -0800, you wrote:

>I came home from work and turned on the K3 and the P3 and then switched to the CW zone of the 40 meter band. The VFO was about 7.009 as left from my last visit yesterday. I turned the VFO up just a tiny bit and this strong, like S9+ broadband noise came through. Funny because I remember looking at the spectrum of the P3 and I did not see anything there.
>
>A long story short. I discovered that this noise was being generated by the K3. I had checked the band with my Icom 756 Pro III and nothing was there except lots of CW signals. I tuned the Pro III around the same spots as the K3. So, I rotated the VFO slow up frequency from 7.009 and at 7.00945 the noise started and continued up to about 7015.5. Now, on the spectrum this was a good 50 dB over and above my normal noise floor (sorry, not sure if I am using the right terminology) and it was the same across the entire spectrum which by the way was set wider then this frequency range of 7009 to 7015. And, all other CW signals disappeared and many of them were stronger then this noise level.
>
>So, if I turned the VFO just past the upper threshold of 7015.5, the noise disappears entirely and there is nothing but normal display of CW signals on the spectrum.
>
>I then decided to power off the K3 and P3. Powered back up and this weird noise phenomena disappeared. Now, the K3 and P3 is acting normal.
>
>Anyone see anything like this?
>
>73, phil, K7PEH
>K3 Serial #3799
>______________________________________________________________
>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

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Stephen Prior

Re: K3 weird noise generation...??

In reply to this post by Phil Hystad-3

Phil

I have seen the same kind of thing twice, only over roughly twice the
frequency range you describe. However on both occasions the only solution
was to do a recalibration of the VCO from the config menu. Simply turning
the K3/P3 off and on did nothing in my case. I recall that on both
occasions the beginning and end of the noise was accompanied by the sound
of a relay operating within the K3. I've not had it now for two or three
weeks.

I run HRD with the K3/P3 as a logging program. This may be significant, I
don't know.

73 Stephen G4SJP

On 31/12/2010 00:41, "Phil Hystad" <[hidden email]> wrote:

>
>I came home from work and turned on the K3 and the P3 and then switched
>to the CW zone of the 40 meter band. The VFO was about 7.009 as left from
>my last visit yesterday. I turned the VFO up just a tiny bit and this
>strong, like S9+ broadband noise came through. Funny because I remember
>looking at the spectrum of the P3 and I did not see anything there.
>
>A long story short. I discovered that this noise was being generated by
>the K3. I had checked the band with my Icom 756 Pro III and nothing was
>there except lots of CW signals. I tuned the Pro III around the same
>spots as the K3. So, I rotated the VFO slow up frequency from 7.009 and
>at 7.00945 the noise started and continued up to about 7015.5. Now, on
>the spectrum this was a good 50 dB over and above my normal noise floor
>(sorry, not sure if I am using the right terminology) and it was the same
>across the entire spectrum which by the way was set wider then this
>frequency range of 7009 to 7015. And, all other CW signals disappeared
>and many of them were stronger then this noise level.
>
>So, if I turned the VFO just past the upper threshold of 7015.5, the
>noise disappears entirely and there is nothing but normal display of CW
>signals on the spectrum.
>
>I then decided to power off the K3 and P3. Powered back up and this
>weird noise phenomena disappeared. Now, the K3 and P3 is acting normal.
>
>Anyone see anything like this?
>
>73, phil, K7PEH
>K3 Serial #3799
>______________________________________________________________
>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
>

Phil Hystad-3

Re: K3 weird noise generation...??

I noticed that the width of this noise seemed to be the width of the pass band since when I changed modes (CW, USB, etc.) the width of the affected frequency spread changed. It also changed when I adjusted the filter width.

On Dec 30, 2010, at 5:02 PM, Stephen Prior wrote:

> Phil
>
> I have seen the same kind of thing twice, only over roughly twice the
> frequency range you describe. However on both occasions the only solution
> was to do a recalibration of the VCO from the config menu. Simply turning
> the K3/P3 off and on did nothing in my case. I recall that on both
> occasions the beginning and end of the noise was accompanied by the sound
> of a relay operating within the K3. I've not had it now for two or three
> weeks.
>
> I run HRD with the K3/P3 as a logging program. This may be significant, I
> don't know.
>
> 73 Stephen G4SJP
>
> On 31/12/2010 00:41, "Phil Hystad" <[hidden email]> wrote:
>
>>
>> I came home from work and turned on the K3 and the P3 and then switched
>> to the CW zone of the 40 meter band. The VFO was about 7.009 as left from
>> my last visit yesterday. I turned the VFO up just a tiny bit and this
>> strong, like S9+ broadband noise came through. Funny because I remember
>> looking at the spectrum of the P3 and I did not see anything there.
>>
>> A long story short. I discovered that this noise was being generated by
>> the K3. I had checked the band with my Icom 756 Pro III and nothing was
>> there except lots of CW signals. I tuned the Pro III around the same
>> spots as the K3. So, I rotated the VFO slow up frequency from 7.009 and
>> at 7.00945 the noise started and continued up to about 7015.5. Now, on
>> the spectrum this was a good 50 dB over and above my normal noise floor
>> (sorry, not sure if I am using the right terminology) and it was the same
>> across the entire spectrum which by the way was set wider then this
>> frequency range of 7009 to 7015. And, all other CW signals disappeared
>> and many of them were stronger then this noise level.
>>
>> So, if I turned the VFO just past the upper threshold of 7015.5, the
>> noise disappears entirely and there is nothing but normal display of CW
>> signals on the spectrum.
>>
>> I then decided to power off the K3 and P3. Powered back up and this
>> weird noise phenomena disappeared. Now, the K3 and P3 is acting normal.
>>
>> Anyone see anything like this?
>>
>> 73, phil, K7PEH
>> K3 Serial #3799
>> ______________________________________________________________
>> 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
>>
>
>
>
>