[Elecraft] k2 noise blanker

[Don Wilhelm]

Brett,

To induce a noise that your KNB2 *should* blank, turn on the preamp and 
tap on Q21 with a metal screwdriver - the clicks should disappear with 
the NB on, which will tell you that your KNB2 is working.

If the noise blankiing is not effective with the particular noise you 
are dealing with, you can try widening the gate pulse by placing an 
additional capacitor in parallel with C11.  I would suggest .001 for 
starters, but increase that to whatever your noise source demands.  BUT, 
consider that an increased gate time will cut wider "holes" on your 
received signal, so there is a compromise between a gate time that 
defeats the noise and good receive audio - if the audio distortion is 
too great, then back off on the added capacitance value.

73,
Don W3FPR

Brett Gazdzinski wrote:
> I have the noise blanker in my K2, and I have yet to find a noise it does 
> anything with.
> It seems to have no impact at all on the receiver, no matter what settings.
>
> I did remove the bypass jumper, but it does not act like it....
>
> Is it supposed to be noticeable at all with it on?
>
> Brett
>   
>