[Elecraft] K4 Question

[Adrian]

On 24/6/20 11:02 am, Jim Brown wrote:
> On 6/23/2020 4:53 PM, Adrian wrote:
>> An excessive strength FT8 signal is easy to remove with notch.
>
> Yes, BUT -- the notch introduces phase shift, which can degrade 
> decoding.  K1JT recommends running the IF wide and letting WSJT-X 
> separate signals.
Ok on that, My experience is that it allowed decode of my target RX., I 
did use narrow notch.
>
> I DO strongly differ with the advice in the WSJT-X manual for setting 
> levels. Instead, I recommend setting audio gains so that the green bar 
> indicating audio level as close as possible to the top without it 
> turning red on when strong signals are present. I find Slow AGC works 
> well for me, because both the strongest signals AND my local noise 
> vary widely.

Yes I do that all possible gain and AGC turned off on low band use, with 
green as high as 80dB with no red seen , for good weak signal decode.

Using low width roofing/dsp filtering around the signal boosts it to 
great extent, using width/shift to focus.