[Elecraft] Fw: K2 Trouble / Problem

[Ron D'Eau Claire]

The K2 noise blanker words extremely well on the types of noise it is
intended to remove. It probably should be called a "high amplitude fast
rise-time noise blanker" for all of those who think that it should =
remove
ALL types of noise. It won't.

Typically, the most difficult sort of noise to deal with is a train of =
very
fast and very loud "pulses" such as the loud Buzzzzzzzzz! you get from =
cheap
lamp dimmers on the lower frequencies or the noise you may hear from an
automobile ignition on the higher bands. It will simply make those kinds =
of
noise "disappear".=20

What the blanker does is to select any signal with a sufficiently-fast =
rise
time and turn off the receiver for a period of time that should match =
the
duration of the pulse. So the signal gets a series of "holes" punched in =
it
that exactly match where the loud noise pulses used to be. That's why =
it's
called a "blanker" and not a "limiter". There is a 'downside' to a noise
blanker. Punching those holes in the signal can cause noise artifacts of
their own, although they are nothing like the mess the blanker removes.
However, to preserve the high performance of the receiver when =
high-impulse
noise is not present, the blanker is designed to be switched on manually
only when needed. When not needed, it should be turned off.

By contrast to the blanker, some receivers use a Noise Limiter. A Noise
Limiter simply limits the maximum amplitude of any signal to some set =
level.
A limiter is good for helping with general "hash" that a blanker can't
separate from normal signals. Limiters seem to have fallen into disuse =
some
decades ago with the growing popularity of AGC in CW and SSB receivers. =
A
limiter won't remove high-impulse noise with very fast rise-times as =
well as
a blanker, but it provides some help on virtually any sort of noise. The =
K2
does NOT have a Noise Limiter.


I don't have the DSP unit, so I can't provide any feedback on that.=20

Ron AC7AC



-----Original Message-----
> Hello!  I know what I am about to ask is probably "a terrible thing to
ask"
> here....
> however, I am ready to buy & have been speaking with alot of owners &
people
> who
> build the units....
>
> It was told to me that 1) the noise blanker for the k2 does not work;
can't
> tell if it
> is on or off    2) DSP is way to complicated to use; end up resetting =
rig
> alot to try
> to use it
>
> The noise blanker to me is the most important....do you need the noise
> blanker when you buy the dsp? It looked like the dsp gave more noise=20
> blanker
functions...
>
> Again, this is very important to me & I would welcome any
> replys....direct would be best without tying up the whole group....
>