[Elecraft] K3 weird noise generation...??

[Phil Hystad]

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" <phystad at mac.com> 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
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> 
> 
>