[Elecraft] Re： Manual notch In K3

[Johnny Siu]

Thanks, James.

Yes, AGC off is the last weapon to use.

73 Johnny VR2XMC



----- 郵件原件 ----
寄件人﹕ JAMES ROGERS <w4atk at bellsouth.net>
收件人﹕ Johnny Siu <vr2xmc at yahoo.com.hk>
傳送日期﹕ 2010/11/10 (三) 9:09:09 PM
主題： Re: [Elecraft] Manual notch In K3

I wanted to check something before I answered this, but yes the notch filter is 
probably in the audio chain, rather than the IF.  I picked a good carrier on my 
K3 and then applied the notch. the carrier was not diminished on the P3 display 
but completely notched out in the audio from the speaker.

If I might suggest, in the situation you described apply the notch,  reduce the 
RF Gain, and turn the AGC off.  This will remove the AGC action on the weak 
signal.  I often do this on weak DX as a matter of practice with or without the 
notch. You can then advance the RF Gain to bring up the weak signal to a 
comfortable level of copy.

73s Jim, W4ATK

On Nov 9, 2010, at 10:18 PM, Johnny Siu wrote:

> Hello Group,
> 
> I attempted to manual notch a strong carrier adjacent to a weak station.
> Although I was able to notch out the strong carrier (from the audio), there 
was
> no reduction in S meter level caused by that strong carrier.  In other words,
> the weak station did not pop out from the noise because the stronger
> carrier de-sensed the K3 AGC.
> 
> Please advise whether my observation is correct.
> 
> TNX,
> 
> Johnny VR2XMC
> 
> 
> 
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JIM ROGERS
w4atk at bellsouth.net
http://web.me.com/jimrogers_w4atk