I’ll also throw in, if you're using the anc4 as designed. I did find it very
helpful for getting rid of a few kinds of noise in few specific circumstances ,
worked great.
your millage my vary
regards
n2ehg
myles
> On Jan 13, 2021, at 1:20 PM, Cianciolo, Paul, W1VLF <pcianciolo@arrl.org>
> wrote:
>
> I call it "quality noise"
> You want just your target noise to invert and cancel.
>
> Anything else will tend to add "new" noises from the pickup antenna.
> See here
>
> https://youtu.be/spre7Wn0Kqs
>
>
> 73,
>
> Paul Cianciolo, W1VLF
> ARRL EMC Engineer
>
> ARRL - The national association for Amateur Radio™
> 225 Main Street, Newington, CT 06111-1400 USA
> Telephone: (860) 594-0392
> FAX: (860) 594-0259
> Email: w1vlf@arrl.org
> World Wide Web: www.arrl.org
>
>
>
> -----Original Message-----
> From: RFI <rfi-bounces+pcianciolo=arrl.org@contesting.com> On Behalf Of Mike
> Martin
> Sent: Wednesday, January 13, 2021 11:57 AM
> To: Dave Cole <dave@nk7z.net>
> Cc: rfi@contesting.com
> Subject: Re: [RFI] Sense antenna for ANC-4 power line rfi?
>
> Hey guys consider this, you can look at a noise on two antennas exactly the
> same but located in different places in your yard and see different noises.
> That's a fact.
> So if you're using a noise cancellation device you can't expect the antenna
> you're using for that device to see the same noise that you see when the
> antenna with the symptoms. So you have to make sure that the cancellation
> device antenna is seeing the same noise that you're picking up in your
> receivers and causing interference to the one it's signal. once you achieve
> that then the noise cancellation device will work quite well. but if your
> noise cancellation device sees a different noise then you're canceling the
> wrong noise therefore it doesn't work properly. I wish I had more time to
> explain further but unfortunately I'm out here looking for noise and don't
> have the time.
> Just so you know I also don't have time to proofread my voice to text message
> so please excuse the mistakes and type of graphical errors. LOL
>
> Happy 2021,
> Mike
>
> Get BlueMail for Android
>
> On Jan 13, 2021, 9:15 AM, at 9:15 AM, Dave Cole <dave@nk7z.net> wrote:
>> Charles,
>>
>> You may find that the phase type noise reducers don't work so well on
>> power line noise... It can help-- but mostly it will not be very
>> effective for distributed RFI sources.
>>
>> The source of transmission can be distributed, (not in all cases),
>> along several hundred, to several thousand feet of power line. This
>> means that depending on the distance traveled down the power line, the
>> distance to your sense antenna, and the distance to your main antenna,
>> RFI will arrive at different times, and hence different phase
>> relationships to each other, from every point along the power line that
>>
>> carries the RFI.
>>
>> Given that the ANC-4 is a phase cancellation device, (it looks at your
>> main antenna, and your sense antenna, and tries to phase cancel an RF
>> signal based on phase relationship), this can cause no end of issues.
>>
>> Now imagine the signals the ANC will see if your RFI is being
>> re-radiated along several hundred, or thousand feet of power line. You
>>
>> will be able to cancel some, but not a lot of the RFI.
>>
>> If you are lucky, you will have a specular source, and no re-radiation,
>>
>> which will allow you to cancel most of the offending signal out...
>>
>> Your idea is a good one, and might help... RFI suppression is always
>> fun, when it works... Good luck. Please do post your results.
>>
>> 73, and thanks,
>> Dave (NK7Z)
>> https://www.nk7z.net
>> ARRL Volunteer Examiner
>> ARRL Technical Specialist, RFI
>> ARRL Asst. Director, NW Division, Technical Resources
>>
>> On 1/12/21 11:07 PM, Charles Plunk wrote:
>>> While waiting on my powerline arc to return in force enough to have
>>> confidence it will be ongoing when I call TVA in, thought I would
>> play
>>> with improving the sense antenna on my Timewave ANC-4. The 3 phase
>> power
>>> runs at the edge of my lot up to the suspect pole. So the noise is
>>> radiating up this way and all the more reason its strong on me I
>>> suspect. I have a storage building underneath the lines. I am
>> thinking
>>> about a vertical made for a scanning receiver I came across and
>> mounting
>>> it up under the lines on that building. I will tack it up there
>> somehow
>>> and move it around to get a sweet spot maybe. Any better ideas?
>>>
>>> Thanks,
>>> Chuck
>>> AF4O
>>>
>>> _______________________________________________
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>>> RFI@contesting.com
>>> http://lists.contesting.com/mailman/listinfo/rfi
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