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Using K3 to measure noise levels

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k1htv

Using K3 to measure noise levels

Using K3 to measure noise levels

Since the beginning of the year I've been plagued with power line noise on the 6 Meter band. Before I called the local power company I used my K3 and rotatable 6M yagi antenna to quantify noise levels in various directions. I wanted to set a baseline to measure any improvement after the power line crew completed their work. Using the K3 with the beam aimed in the most quiet direction I was able to get a 0.0 dBV reference level based on the AFV reading for that particular direction. Then rotating the yagi, I took dBV readings every 10 degrees from 000 degrees to 360 degrees.

If you have a rotatable beam for the VHF, UHF or higher HF bands and would like to map the noise levels in various directions around your QTH, here is how to do it with your K3.

- Turn on your K3 and move to an quiet frequency on the band to be used.
- Turn TECH mode to 'ON"' (Hold 'Menu' button to get to 'CONFIG' menu)
- Rotate VFO-B to 'TECH MD' and rotate VFO-A dial to display "ON".
- Tap MENU button
- Tap 'DISP' button
- Rotate VFO-B dial until 'AFV nnnn' is displayed. This AFV reading (nnnn) will be used as the 0.0 dBV reference level to which noise levels in other directions will be compared.
- Rotate VFO-B to the maximum clockwise direction to read 'dBV'.
- Record this reading and its beam heading. It should be close to 0.0 DB (+) plus or minus (-) a half DB or so.
***Note*** Do NOT move VFO-B from 'dBV' to 'AFV'. Doing so will reset the reference voltage.

If you have a long yagi you probably want to measure every 10 degrees. On the higher HF bands every 30 degrees should do.
- When finished taking all of your readings for each beam heading, tap "DISP" to return to the normal VFO-B display.

After making noise measurements a few months after the initial ones, I was able to determine the level of improvement (in dB) resulting from the work done by the power company crew. I also discovered a new noise source in a different direction which needs to be corrected.

In addition to making noise measurements You can also use the K3 AFV/dBV procedure described above to plot your yagi pattern. All you need is a Ham friend within a few miles of you to provide a steady QRP level carrier (With ID every 10 minutes, of course).

I was able to plot my 6M yagi pattern and determine that something, possibly guys or HF antennas, was distorting the beam's pattern in certain directions.

Hope that you found this K3 information of some use.

73,
Rich - K1HTV
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k5oai

Re: Using K3 to measure noise levels

you might find this software useful:
http://www.seed-solutions.com/gregordy/Software/SMeterLite.htm

On 10/12/2013 6:09 PM, Rich - K1HTV wrote:

> Using K3 to measure noise levels
>
> Since the beginning of the year I've been plagued with power line noise on the 6 Meter band. Before I called the local power company I used my K3 and rotatable 6M yagi antenna to quantify noise levels in various directions. I wanted to set a baseline to measure any improvement after the power line crew completed their work. Using the K3 with the beam aimed in the most quiet direction I was able to get a 0.0 dBV reference level based on the AFV reading for that particular direction. Then rotating the yagi, I took dBV readings every 10 degrees from 000 degrees to 360 degrees.
>
> If you have a rotatable beam for the VHF, UHF or higher HF bands and would like to map the noise levels in various directions around your QTH, here is how to do it with your K3.
>
> - Turn on your K3 and move to an quiet frequency on the band to be used.
> - Turn TECH mode to 'ON"' (Hold 'Menu' button to get to 'CONFIG' menu)
> - Rotate VFO-B to 'TECH MD' and rotate VFO-A dial to display "ON".
> - Tap MENU button
> - Tap 'DISP' button
> - Rotate VFO-B dial until 'AFV nnnn' is displayed. This AFV reading (nnnn) will be used as the 0.0 dBV reference level to which noise levels in other directions will be compared.
> - Rotate VFO-B to the maximum clockwise direction to read 'dBV'.
> - Record this reading and its beam heading. It should be close to 0.0 DB (+) plus or minus (-) a half DB or so.
> ***Note*** Do NOT move VFO-B from 'dBV' to 'AFV'. Doing so will reset the reference voltage.
>
> If you have a long yagi you probably want to measure every 10 degrees. On the higher HF bands every 30 degrees should do.
> - When finished taking all of your readings for each beam heading, tap "DISP" to return to the normal VFO-B display.
>
> After making noise measurements a few months after the initial ones, I was able to determine the level of improvement (in dB) resulting from the work done by the power company crew. I also discovered a new noise source in a different direction which needs to be corrected.
>
> In addition to making noise measurements You can also use the K3 AFV/dBV procedure described above to plot your yagi pattern. All you need is a Ham friend within a few miles of you to provide a steady QRP level carrier (With ID every 10 minutes, of course).
>
> I was able to plot my 6M yagi pattern and determine that something, possibly guys or HF antennas, was distorting the beam's pattern in certain directions.
>
>
> Hope that you found this K3 information of some use.
>
> 73,
> Rich - K1HTV

--

GB & 73
K5OAI
Sam Morgan
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k5oai

Re: Using K3 to measure noise levels

also a review of S-Meter Lite here:
http://nk7z.net/review-of-s-meter-lite/

and more info on how Nk&z used it to chase his RFI problem(s) here:
http://nk7z.net/rfi-at-my-home-qth/

On 10/12/2013 6:24 PM, Sam Morgan wrote:

> you might find this software useful:
> http://www.seed-solutions.com/gregordy/Software/SMeterLite.htm
>
> On 10/12/2013 6:09 PM, Rich - K1HTV wrote:
>> Using K3 to measure noise levels
>>
>> Since the beginning of the year I've been plagued with power line
>> noise on the 6 Meter band. Before I called the local power company I
>> used my K3 and rotatable 6M yagi antenna to quantify noise levels in
>> various directions. I wanted to set a baseline to measure any
>> improvement after the power line crew completed their work. Using the
>> K3 with the beam aimed in the most quiet direction I was able to get a
>> 0.0 dBV reference level based on the AFV reading for that particular
>> direction. Then rotating the yagi, I took dBV readings every 10
>> degrees from 000 degrees to 360 degrees.
>>
>> If you have a rotatable beam for the VHF, UHF or higher HF bands and
>> would like to map the noise levels in various directions around your
>> QTH, here is how to do it with your K3.
>>
>> - Turn on your K3 and move to an quiet frequency on the band to be used.
>> - Turn TECH mode to 'ON"' (Hold 'Menu' button to get to 'CONFIG' menu)
>> - Rotate VFO-B to 'TECH MD' and rotate VFO-A dial to display "ON".
>> - Tap MENU button
>> - Tap 'DISP' button
>> - Rotate VFO-B dial until 'AFV nnnn' is displayed. This AFV reading
>> (nnnn) will be used as the 0.0 dBV reference level to which noise
>> levels in other directions will be compared.
>> - Rotate VFO-B to the maximum clockwise direction to read 'dBV'.
>> - Record this reading and its beam heading. It should be close to 0.0
>> DB (+) plus or minus (-) a half DB or so.
>> ***Note*** Do NOT move VFO-B from 'dBV' to 'AFV'. Doing so will reset
>> the reference voltage.
>>
>> If you have a long yagi you probably want to measure every 10 degrees.
>> On the higher HF bands every 30 degrees should do.
>> - When finished taking all of your readings for each beam heading, tap
>> "DISP" to return to the normal VFO-B display.
>>
>> After making noise measurements a few months after the initial ones, I
>> was able to determine the level of improvement (in dB) resulting from
>> the work done by the power company crew. I also discovered a new noise
>> source in a different direction which needs to be corrected.
>>
>> In addition to making noise measurements You can also use the K3
>> AFV/dBV procedure described above to plot your yagi pattern. All you
>> need is a Ham friend within a few miles of you to provide a steady QRP
>> level carrier (With ID every 10 minutes, of course).
>>
>> I was able to plot my 6M yagi pattern and determine that something,
>> possibly guys or HF antennas, was distorting the beam's pattern in
>> certain directions.
>>
>>
>> Hope that you found this K3 information of some use.
>>
>> 73,
>> Rich - K1HTV
>

Jim Brown-10

Re: Using K3 to measure noise levels

In reply to this post by k1htv

On 10/12/2013 4:09 PM, Rich - K1HTV wrote:
> Turn on your K3 and move to an quiet frequency on the band to be used.
> - Turn TECH mode to 'ON"' (Hold 'Menu' button to get to 'CONFIG' menu)

Before beginning this, the AGC must be OFF. That's because the
voltmeter is reading the audio voltage. I know this because I first made
some completely useless measurements with the AGC on. :)

73, Jim K9YC

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David Cutter

Re: Using K3 to measure noise levels

In reply to this post by k5oai

For anyone serious about long term calibrated recordings of noise, see my
article under Citizen Science in the latest QST.

73

David
G3UNA

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k1htv

Re: Using K3 to measure noise levels

David,
I checked the Sept., Oct. and Nov. issues of QST, looking for your article about long term calibrated recording of noise but couldn't find it. Also couldn't find any mention of 'Citizen Science'. Where can we find your article ?

73,
Rich - K1HTV

= = =

----- Original Message -----
From: "David Cutter" <[hidden email]>
To: "Sam Morgan" <[hidden email]>, "Rich - K1HTV" <[hidden email]>, "Elecraft Reflector" <[hidden email]>
Sent: Tuesday, October 15, 2013 6:05:33 AM
Subject: Re: [Elecraft] Using K3 to measure noise levels

For anyone serious about long term calibrated recordings of noise, see my
article under Citizen Science in the latest QST.

73

David
G3UNA

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N8MSA

Re: Using K3 to measure noise levels

November 2013 QST Technical Correspondence - "More Citizen Science", page 62. It isn't so much an article as it is a letter, and isn't explicitly mentioned in the table of contents.

Mike Alexander - N8MSA

[hidden email]

----- Original Message -----
From: "Rich - K1HTV" <[hidden email]>
To: "David Cutter" <[hidden email]>
Cc: "Elecraft Reflector" <[hidden email]>
Sent: Tuesday, October 15, 2013 7:22:34 AM
Subject: Re: [Elecraft] Using K3 to measure noise levels

David,
I checked the Sept., Oct. and Nov. issues of QST, looking for your article about long term calibrated recording of noise but couldn't find it. Also couldn't find any mention of 'Citizen Science'. Where can we find your article ?

73,
Rich - K1HTV

= = =

----- Original Message -----
From: "David Cutter" <[hidden email]>
To: "Sam Morgan" <[hidden email]>, "Rich - K1HTV" <[hidden email]>, "Elecraft Reflector" <[hidden email]>
Sent: Tuesday, October 15, 2013 6:05:33 AM
Subject: Re: [Elecraft] Using K3 to measure noise levels

For anyone serious about long term calibrated recordings of noise, see my
article under Citizen Science in the latest QST.

73

David
G3UNA

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k5oai

Re: Using K3 to measure noise levels

In reply to this post by k1htv

pg 62 Nov 2013 QST

On 10/15/2013 06:22 AM, Rich - K1HTV wrote:

> David,
> I checked the Sept., Oct. and Nov. issues of QST, looking for your article about long term calibrated recording of noise but couldn't find it. Also couldn't find any mention of 'Citizen Science'. Where can we find your article ?
>
> 73,
> Rich - K1HTV
>
> = = =
>
> ----- Original Message -----
> From: "David Cutter" <[hidden email]>
> To: "Sam Morgan" <[hidden email]>, "Rich - K1HTV" <[hidden email]>, "Elecraft Reflector" <[hidden email]>
> Sent: Tuesday, October 15, 2013 6:05:33 AM
> Subject: Re: [Elecraft] Using K3 to measure noise levels
>
> For anyone serious about long term calibrated recordings of noise, see my
> article under Citizen Science in the latest QST.
>
> 73
>
> David
> G3UNA
>
>

PA5MW

Re: Using K3 to measure noise levels

Some remarks on doing this 360deg noise measurement:

- Any SDR with averaging set high, will result in more stable and accurate data
- You can use a certain time slot to decide for the value you measure (I used 20s)
- You first need to practise this on a few occasions
- Do it at few different time slots per day
- Avoid time slots around where your neighborhood switch on there TV sets (before the news)

A 360 deg radarview on the found results may look like this:
http://2.bp.blogspot.com/_iLgsAFYbyTM/SeJXpf0UXzI/AAAAAAAAAic/78zSIjWgPTE/s1600/144Mhz_radarview.jpg

Explanation on how I did this back in 2009 can be found at:
http://pa5mw.blogspot.nl/2009/04/location-location-location_12.html

You will see one other radarview from a ham nearby (6mls NW) with a totally different result.
Location, location, location. And neighbors are a bitch :)

I'm currently exchanging the antenna and will do a new measurement within a few weeks from now.
Let's see what has changed.......

73 Mark, PA5MW