[Kenwood] comments on 2000 rig

[Dr. Gerald N. Johnson, electrical engineer]

Actually noise blankers don't introduce distortion of the receive signal
except by chopping holes in that signal. That is all Lamb style noise
blankers. They work by shutting off the receiver with a rapid gate
during the noise pulse. Because its short and downward, we don't notice
it by ear (the narrow filters probably ring to fill in the hole). To be
fast enough to be effective and not audible, the noise processing has to
be where the receiver bandwidth is significantly greater than what we
desire for communications bandwidth (generally something under 2.5 KHz),
probably a bandwidth of at least 25 or 50 kHz. The chopping is applied
to ALL signals in that wide band. If there are any other signals in that
pass band, especially louder than the one we are listening to, the noise
chops those clean signals making them splatter. That we hear as
distortion even tuning off the only signal on the band. Actually is a
mix of the noise pulses and the strong signals.

Its what noise blankers do, there might be a better way in DSP, but I've
not proven that invention yet.

73, Jerry, K0CQ
-- 
Entire content copyright Dr. Gerald N. Johnson, electrical engineer.
Reproduction by permission only.