[Elecraft] K3: 200Hz filter and manual notching oddity

[Arie Kleingeld PA3A]

Hi,


FW: uC 05.41 +   d1/2  2.76 +  FL1.15

Switching to manual notch in both modes.
Notch working on CW as it should, notch switches off at 100hz en 50 Hz 
BW. (No serious problem :-) )
Notch working on SSB and data as it should, also at lowest BW, which is 
150Hz for SSB.

73
Arie PA3A


Op 22-10-2012 8:24, Dan Sherwood schreef:
> All,
>
> I purchased 200 Hz 5-pole filters for my K3.  They work fine except for one
> oddity:  If I set a manual notch at exactly 700 Hz, then sweep the bandwidth
> control from the maximum of 2.5 KHz to a minimum 0.05 KHz, I would expect
> the audio to disappear at whatever the notch width is, (Passband <= NOTCH),
> and stay that way.  It does not.
>
> My findings:
>
> Between bandwidth settings 2.8 and 0.30 ­ full audio. (FL3 and FL4, 2.8K and
> 500Hz transitioning at 0.5)
> Bandwidth 0.25 ­ abrupt total silence, FL4 (500Hz filter) (might have
> expected this at 0.20 instead)
> Bandwidth 0.20 ­ total silence, FL5(new 200Hz filter)
> Bandwidth 0.15 ­ total silence, FL5
> Bandwidth 0.10 ­ full audio abruptly returns, FL5 (unexpected)
> Bandwidth 0.05 ­ full audio, FL5 (unexpected)
>