[Elecraft] KNB2 does not work on my power line noise

[Ron D'Eau Claire]

Even on 80 meters, where the background noise is fairly high, I often =
turn
on the pre-amp to "quiet" the receiver because the blanker doesn't 'kick =
in'
on the lower level.=20

I'm not sure why that is - whether there is some averaging going on that
affects the minimum level. I've found the "low threshold" setting to =
have
minimal effect, but generally turning the Preamp ON will drop a S9++++ =
lamp
dimmer roar down to S3 or so.=20

Ron AC7AC

-----Original Message-----
GM Roger:

What S-meter reading do you get from the line noise at your QTH?

All noise blankers must have a minimum signal level from the noise =
before=20
they can properly sense it and begin the blanking process.

If your QTH is very quiet (other than the line noise), then even a =
minute=20
amount of line could sound terrible, but still be below the minimum=20
blanking level.

Since your NB did work correctly at your frien'ds QTH, but not yours, =
this=20
could be the cause...=20
73,

Tom    N0SS