[Elecraft] Notch

[Ron D'Eau Claire]

No, Tim, you didn't miss anything.

For SSB, it seems like more and more rigs are going to some sort of DSP
that includes an automatic notch function. As a brass pounder, I have
little experience with those.

For CW, current operating practices seem to favor using the
narrowest-possible bandwidth which eliminates the need for a notch
filter.

I miss a notch filter, because I like using a w-i-d-e bandwidth filter -
as wide as QRM will allow. And sometimes I must crank down the bandwidth
just because of ONE loud signal nearby. It feels like I'm a horse
wearing blinders, using a very tight filter. I'm completely unaware of
what's going on around me "on the band". 

A good notch filter can be added at the audio output. One disadvantage
of doing that is that the AGC MUST be turned OFF, or a loud signal will
cause the AGC to turn down the overall gain on the weaker signal you are
trying to copy. For us OTs who still tend to ignore "newfangled" gadgets
like AGC and control the gain ourselves, that's no problem. But it can
be irritating to someone used to AGC. 

As for "why not?", I can't answer that question. I've had a "notch
filter" on almost every "high performance" receiver I've owned, since
the HRO-5 I bought in the mid 1950's. And the "notch" was handled by the
i-f filter where it should be to boot!  You are absolutely right. It's
nothing new. Gee, maybe it's gotten too old... <G>. 

Ron AC7AC
K2 # 1289


Hi folks -
  I very seldom have ever needed to use a notch control, but the other
night I used one on another rig and was surprised at how well it worked
and useful.
  Have I missed something or is there no notch control on the K2/100 and
if not, why not? Looks like it was pretty standard on rigs at least as
far back as Drakes. Can some one clue in the clueless. Thanks.

73/Tim NZ7C