[Elecraft] KX3

[Don Wilhelm]

John,

This reflector covers all Elecraft products.

The notch filter is only used to notch out an *unwanted* signal - use it 
carefully since you can easily notch out the signal that you are trying 
to receive.

First use the DSP filter to home in on the wanted signal - the PBT knob. 
  The roofing filter will follow along with the width of the DSP passband.

Once you get the wanted signal, you can optionally use APF if it is of 
benefit.

If there is an unwanted signal within the passband, you can use NOTCH to 
reduce it.

73,
Don W3FPR

On 4/24/2018 6:03 AM, john daws wrote:
> (not sure if this is the same as using the KX3 users group but here goes)
> 
> Would appreciate advice on the use of the* notch filter* on my KX3
> 
> It is fitted with* KX3FL3* roofing filters. I only use CW
> 
> Once I have spotted a weak signal I can  use these to narrow down and
> filter out unwanted noise on the chosen signal
> 
> I can also apply the APF filter and tune that way.
> 
> Recent advice suggested that the APF function  works best when when used
> with a  DSP/crystal filter WIDTH setting of 300-500 Hz
> 
> Does this mean I switch on the Notch and tune to this range on the notch
> setting and how does this work with the bandwidth settings on the PBT
> function?
> 
> Do I leave the notch on whilst tuning for other signals or only use it when
> I have a weak signal in the first place.
> 
> Trial and error has left me doubtful whether I am getting the best out of
> this function.