[Elecraft] Noise Blanker

Sat Sep 28 11:17:01 2002

Hello, All!

The K2's noise blanker is the most effective noise blanker I have ever
heard on a commercial amateur radio transceiver.

I use my K2 for weak signal VHF/UHF/microwave work, including 144 MHz
EME.  I have a location filled with pulse noise and the K2 outperforms
all of the commercial rigs I have tried, up to and including the
FT-1000MP, which has a very highly regarded receiver.  If I am doing EME
or other weak signal work with a commercial rig, when it is noisy I turn
off the FT1000 and go with the K2.  It far outperforms all of the
competition.

Therefore, I think that if you are not seeing a difference and your K2
has been built correctly, then either (1) you have no noise or (2) it is
not pulse noise.

In your case I would worry about a construction error or a bad or
incorrect part as I noted no increase in noise after I installed the
KNB2, and have not heard of this happening from anyone else.

Hearing that the K2 Noise Blanker 'doesn't work' or 'adds noise' is to
me about the same as hearing 'my Lamborghini doesn't have any pickup';
something is wrong in your particular case; either a construction error
or a bad or incorrect part.  These are NOT expected problems with the
KNB2, which has stellar and frankly unequaled performance.

I hope that helps.

73,

Roger Rehr
W3SZ   FN20ah
2 Merrymount Road
Reading, PA  19609-1718
http://www.qsl.net/w3sz

> -----Original Message-----
> From: [email protected] 
> [mailto:[email protected]] On Behalf Of postal_guy
> Sent: Friday, September 27, 2002 9:36 PM
> To: [email protected]
> Subject: [Elecraft] Noise Blanker
> 
> 
>   Although I'm still very impressed and satisfied with my new 
> K2, I've yet to notice much of a difference in using the 
> Noise Blanker. I could 'see' a slight difference using the 
> Spectrogram program but could not hear much of one. Switching 
> to hi or low threshold did'nt change much of anything either. 
> I just thought that maybe there was'nt any electrical noise 
> to filter out around here.
>   
>   Unrelated to the KNB2, after seeing the suggestion about 
> swapping out the R1 resistor (control board), I changed mine 
> to 49k and heard some improvement, (and still found little 
> use for the KNB2), so I changed it again to 39k and can hear 
> even more of an improvement.
> 
>   However, now when I try the KNB2, it actually ADDS 
> interference noise. In hi-threshold, it adds some 
> clicking/popping sounds; in lo-threshold, it adds a "roaring 
> hiss" sound. Not that I really found a need to use it anyway, 
> but has anyone else experienced this? So far I dont mind the 
> trade-off, but I would like to see a remedy for this, other 
> than going back to the 51k value.
> 
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