Re: K3: killing RX key clicks

Posted by P.B. Christensen on Dec 01, 2009; 5:57pm
URL: http://elecraft.85.s1.nabble.com/K3-killing-RX-key-clicks-tp4093607p4095129.html

All good suggestions, Ron -- including turning off the NB if not mentioned
previously.  Engaging the NB function oftentimes produces
internally-generated clicks.

Paul, W9AC

----- Original Message -----
From: "Ron D'Eau Claire" <[hidden email]>
To: "'Elecraft Reflector'" <[hidden email]>
Sent: Tuesday, December 01, 2009 12:51 PM
Subject: Re: [Elecraft] K3: killing RX key clicks

> Key clicks can be generated by several different mechanisms within the
> receiver itself. Paradoxically, it's easier to produce false clicks with a
> high performance receiver than it is with a lesser receiver.
>
> These have nothing to do with the transmitted signal.
>
> The first line of "defense" is to turn off the Preamp and turn on the
> Attenuator to reduce the overall strength of the signals. Next is to set
> the
> AGC to "Slow" to ensure a strong signal isn't within the roofing filter
> bandpass and triggering the AGC while the variable DSP filter is set
> narrow
> so the beat note isn't heard. In some cases using the RF gain to control
> the
> level helps a great deal. Another approach is to use a narrower roofing
> filter or to shift your bandpass so the edge of the roofing filter is very
> close to the desired signal on the side toward the interfering station and
> as far from the interfering station as possible. Shifting the bandpass may
> require you open up your DSP bandwidth to continue to hear the desired
> signal or shifting the DSP filter position within the roofing filter
> bandpass.
>
> And, remember, "clicks" are an essential component of a CW signal. They
> are
> the sidebands created by modulating (keying) the signal. Very careful
> shaping of the keying envelope, such as used in the K2 and K3, can
> minimize
> clicks while maintaining an easily readable signal, but the only way to
> completely eliminate clicks is to not key the signal at all. With a really
> high-performance you can snuggle up very close to a signal, as many here
> have noted. When you do that, you're much more likely to hear the
> essential
> clicks required for good keying.
>
> Ron AC7AC
>
>

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