[Elecraft] Filters

[Bill Frantz]

Hi Mike and congratulations on the new-to-you K3.

When thinking about filters for the K3 or K3S remember that they 
are roofing filters. The DSP code also filters the signal, so 
unless you have a problem with nearby strong signals, the DSP 
filtering may do everything you need. For example, when I find 
very close CW signals, I may dial the DSP width down to 50 or 
100 Hz, which frequently eliminates the interference. On the 
other hand, during a contest when a local station is calling CQ 
400 Hz up from the station I'm trying to work, the 250 Hz filter 
is very helpful.

The FM filter can be used for AM operations.

My filter configuration is:

    13 KHz FM filter
    2.7 KHz 5 pole filter
    2.1 KHz 8 pole filter for SSB
    .25 KHz 8 pole filter for CW and digital operation

I just let the radio pick the right filter as I change the DSP 
bandwidth. It all works very nicely during contests and DX chasing.

73 Bill AE6JV

On 1/30/17 at 5:21 PM, mtruss8841 at comcast.net (mtruss) wrote:

>I have purchased a used  K3, serial number 3000 or so, it has been sent back
>to Elecraft for updates etc  and returned to me working great so far. I
>would like to update some things especially the roofing filters first so the
>question I would like to ask is  Has anybody upgraded from the 2.7 five pole
>filter to the 2.8 eight pole filter? I understand the 8 pole is a wider
>filter with 3 more filtering  crystals , does it make any difference in
>received audio? also could I use the fm filter for use in the 
>am position. Any other suggestions would be appreciated.
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