AGC Attack with NB Engaged

K1ESE

My neighbor has an electric fence along one edge of my property. It makes a lot of noise in my Flex 6500 using SmartSDR 2.4.10.

After seeing Tim's presentation on the QSO Today Hamfest about receiver adjustments, I have been using the Noise Blanker at a low setting (10 or less). That eliminates the noise.

I run a CW traffic net and when a very strong station calls in the first letter of the call is highly distorted. After that copy is fine. It's like the AGC is slow to attack for part of a second. Or it may be that the Noise Blanker is confused at first.

Is there a setting I can adjust to minimize the effect?

I had been using the Wideband Noise Blanker and it doesn't have this slow attack problem, but it also is not as effective at eliminating the noise.

Tim - W4TME

I doubt it is the AGC that is causing it, but it is the initial "training" time that the NB does when it detects new signals. If changing the AGC to slow or fast makes no difference, then it is the NB that is responsible. I'd normally tell you to reduce the NB threshold, but you already have it very low to start with.

Tim - W4TME

What is your AGC setting?

K1ESE

Hi Tim -

ACG-T is about 25 and AGC is MED.