Alignment guidance for NM0S Buzz-kill


Kenneth Ketner
 

Looks like I got same working. However adjusting the alignment pots seems to have no effect on noise level. Does anyone have advice on aligning or troubleshooting concerning this issue? What alignment signal should one input? 

I used the signal from my noisy vertical to a rx thru BK to earphones. Am I trying to kill the wrong noise (antenna rfi)? Or am I trying to kill static noise on power line coming from power supply of XCVR?

73 de KA5ELD
Ken Ketner


AG1P Ron
 

I can’t help you on alignment. My unit worked right off. It does gud job taking out 60 cycle power line RFI. Think that is what it is designed to do.

72 - Ron - AG1P

 

From: main@4SQRP.groups.io [mailto:main@4SQRP.groups.io] On Behalf Of Kenneth Ketner via groups.io
Sent: Saturday, October 16, 2021 8:46 AM
To: main@4SQRP.groups.io
Subject: [4SQRP] Alignment guidance for NM0S Buzz-kill

 

Looks like I got same working. However adjusting the alignment pots seems to have no effect on noise level. Does anyone have advice on aligning or troubleshooting concerning this issue? What alignment signal should one input? 

I used the signal from my noisy vertical to a rx thru BK to earphones. Am I trying to kill the wrong noise (antenna rfi)? Or am I trying to kill static noise on power line coming from power supply of XCVR?

73 de KA5ELD
Ken Ketner


Johnny AC0BQ
 

Gm Ken
You will need to email Dave Cripe NM0S.
He is the designer.
I copied him with my reply.
72
Johnny ACØBQ 


On Sat, Oct 16, 2021 at 10:59 AM AG1P Ron <ag1p@...> wrote:

I can’t help you on alignment. My unit worked right off. It does gud job taking out 60 cycle power line RFI. Think that is what it is designed to do.

72 - Ron - AG1P

 

From: main@4SQRP.groups.io [mailto:main@4SQRP.groups.io] On Behalf Of Kenneth Ketner via groups.io
Sent: Saturday, October 16, 2021 8:46 AM
To: main@4SQRP.groups.io
Subject: [4SQRP] Alignment guidance for NM0S Buzz-kill

 

Looks like I got same working. However adjusting the alignment pots seems to have no effect on noise level. Does anyone have advice on aligning or troubleshooting concerning this issue? What alignment signal should one input? 

I used the signal from my noisy vertical to a rx thru BK to earphones. Am I trying to kill the wrong noise (antenna rfi)? Or am I trying to kill static noise on power line coming from power supply of XCVR?

73 de KA5ELD
Ken Ketner

--
Check out the 4SQRP website at 4sqrp.com


nm0s_qrp
 

Just keep in mind that the Buzz-Kill is for taking out 60 Hz noise.  This can be from motors, power supplies, or bad station grounding.  A lot of switching power supply noise will show up as 60 Hz noise in your receiver.  Alignment should be done with R14 centered, and R8 used to obtain the initial null.  Only then should R14 be touched.  The null is pretty sharp, so tune R8 slowly until the level of any 60 Hz noise drops dramatically.