[Elecraft] KX-1: Broadcast breakthrough on 20m

[Don Wilhelm]

Stephen,

The first thing I would suggest is to see if the KX1 is really receiving 
on 20 meters, or perhaps on some other frequency band.  What I am 
thinking is that the firmware chip may not be fully seated in the 
socket, which will cause to DDS output to be on some unknown frequency.

Another thing that could cause similar problem is a distorted DDS output 
waveshape - check inductors L4 and L5 for damage and capacitors C50, C51 
and C52.

The other possibility is that the KX1 was actually responding to the 
image.  When tuned to USB at 14.2, the DDS output is 4.9 kHz below the 
received frequency, and there could be leak-through of strong signals 
near 4.4 MHz.

73,
Don W3FPR

Stephen Prior wrote:
> I have just returned from a few days away in Italy with my xyl.  Being
> limited with what we could take (we were flying, usually we drive), I took
> along my KX-1.  It was the first time that I had used it this year- blame
> the K3 for that!
>
> When I used it last (in CT and EA in summer 2008) I posted to the reflector
> that I had suffered Broadcast interference on 20m after the radio had
> suffered a rather severe blow caused by my son tripping up over the antenna
> wire and launching the KX-1 some distance!  As a result of this mishap I
> discovered that I had a broken bnc socket which I have since replaced.  I
> imagined that this might have been at the root of the problem and that all
> would be well.
>
> However, on the aforementioned trip I threw about 10m of wire out of the
> hotel window (just to listen) and was surprised to find three or four strong
> broadcast stations around 14.2MHz, so strong in fact that they were badly
> interfering with QSOs.  I cannot help but think that there is something else
> awry with the KX-1.  I have checked the filter alignment and all seems okay
> according to the manual.  Is there anything else I should check for?  I
> don't expect the kind of performance I get from the K2 or K3, but it seems
> to me that the KX-1 should be performing better than this.  It also seems a
> little quiet.
>
> Any suggestions appreciated
>
> 73 Stephen G4SJP
>
>
>
>
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