KNB2 - can´t bring it to work

[Karsten Eppert (DK4AS)]

I have sharp pulses on all bands hitting the band about once per second,
which the noiseblanker of my old IC 735 kills, but not so my K2 S/N 4765.
I can - more or less - read a circuit diagramm (I don´t understand each
components function in detail  yet) I´ve tried some signal tracing,
couldn´t identify a faulty component and can´t find out, what is wrong.
Is there an info-sheet available, what has to be seen with a
dual-scope-oszilloscope at which point and at what siganl level?

73
Karsten
DK4AS
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[Darrell Bellerive]

Karsten,

Sounds like the noise is outside of the KNB2's range. There is a mod for wider
spaced noise like you describe. See
http://www.qslnet.de/member/la3za/K2/modAny.html#KNB2
What you describe sounds like an electric fence.

There was some discusion about an improved noise blanker on the mailing list a
while back. Perhaps Wayne or Eric might comment on whether Elecraft will be
introducing a new noise blanker in the future.

73,
Darrell  VA7TO  K2#5093


On January 22, 2006 06:43 am, Karsten Eppert(DK4AS) wrote:

> I have sharp pulses on all bands hitting the band about once per second,
> which the noiseblanker of my old IC 735 kills, but not so my K2 S/N 4765.
> I can - more or less - read a circuit diagramm (I don´t understand each
> components function in detail  yet) I´ve tried some signal tracing,
> couldn´t identify a faulty component and can´t find out, what is wrong.
> Is there an info-sheet available, what has to be seen with a
> dual-scope-oszilloscope at which point and at what siganl level?
>
> 73
> Karsten
> DK4AS
> _______________________________________________

--
Darrell Bellerive
Amateur Radio Stations VA7TO and VE7CLA
Grand Forks, British Columbia, Canada
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[K3yt]

Hi Karsten,
 
I have found the same thing.  I have bad power line noise.
Sometime the K2 NB takes it all out,  sometimes not.
 
My IC-735 takes all the noise out.
 
I get the KNB2 to work sometimes by putting the pre-amp
ON, then try both high and low thresholds, and both timings.
 
73 de K3YT
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[Karsten Eppert (DK4AS)]

Thank you Darrell,
I checked the pulse width, and in fact it is 500 usec or broader, while
the KNB2 spec is 10 to 70 usec.
Seems I have to play with C11 and C12.
Still, if  could get hold of a diagram, that shows what to measure
where, it would be appriciated.
73
Karsten
DK4AS

Darrell Bellerive schrieb:

>Karsten,
>
>Sounds like the noise is outside of the KNB2's range. There is a mod for wider
>spaced noise like you describe. See
>http://www.qslnet.de/member/la3za/K2/modAny.html#KNB2
>What you describe sounds like an electric fence.
>
>There was some discusion about an improved noise blanker on the mailing list a
>while back. Perhaps Wayne or Eric might comment on whether Elecraft will be
>introducing a new noise blanker in the future.
>
>73,
>Darrell  VA7TO  K2#5093
>
>
>On January 22, 2006 06:43 am, Karsten Eppert(DK4AS) wrote:
>  
>
>>I have sharp pulses on all bands hitting the band about once per second,
>>which the noiseblanker of my old IC 735 kills, but not so my K2 S/N 4765.
>>I can - more or less - read a circuit diagramm (I don´t understand each
>>components function in detail  yet) I´ve tried some signal tracing,
>>couldn´t identify a faulty component and can´t find out, what is wrong.
>>Is there an info-sheet available, what has to be seen with a
>>dual-scope-oszilloscope at which point and at what siganl level?
>>
>>73
>>Karsten
>>DK4AS
>>_______________________________________________
>>    
>>
>
>  
>

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