K3 Notch Filter

[paulb]

Hello folks

Owned my k3 for about 3 years,  performance
is spot on, just one very minor operator feature
that I've never quite got comfortable with;

The K3 notch filter appears to be after the IF system?
eg audio type notch, the S meter does not show any
signal change on steady carrier.

Is this a big deal in the K3 ?

Other similar price major brand in the shack uses IF type notch
which knocks out the offending signal almost into
the background noise.

K3 here is latest firmware, with all hardware updates.

Interested to hear comments

reply off  list if preferred


thanks

cheers
Paul
zl1ajy

[Arie Kleingeld PA3A-2]

Paul,

Yes, the IF notch is kept outside the AGC - loop. And I am with you on
this. It would be so nice to have the notch inside the loop.

More than one reason for the notch outside the agc-loop have been
communicated in this list.

Summing up a few, but please let the experts help me on this:
- A too strong signal cannot be handled well bij the A/D convertor so
hardware AGC will have to kick in. This is , I think, a good reason, BUT
only for strong signals.
- Also increasing distortion is mentioned (IMD?) as a problem. Maybe so,
but I feel that the AGC that decreases the volume of the whole signal is
also a large distortion. I cannot tell what is worse and how much
distortion would be audible if the notch was inside the agc-loop (except
for the hardware AGC)
- is there more?

Anyway, the K3 is a fine rig in many things, but it is not an ideal rig.
This notch-thing is one of the not ideal features.

73
Arie PA3A
K3 #12xx



Op 27-4-2012 8:10, paulb schreef:

> The K3 notch filter appears to be after the IF system?
> eg audio type notch, the S meter does not show any
> signal change on steady carrier.
>
> Is this a big deal in the K3 ?
>
>
> cheers
> Paul
> zl1ajy
>
>
>

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