[ADXA] noise chasing

[Dennis Schaefer]

Thanks, Mark - you’ve had plenty of experience with noise.  I’ll snoop
around at higher frequencies and see what I can find.   Appreciate it!

Dennis

On Sun, Dec 29, 2024 at 6:08 PM Mark Graves <mgraves at avecc.com> wrote:

> Usually….finding and fixing the noise that is detectable up high
> (300,50,30 MHz) will solve what you hear on the low bands. Sometimes, but
> very very rarely, you can have a higher frequency noise generator on the
> line equipment that is frequency selective. Almost always it’s audio
> signature is coming from a 120 Hz or 8.3 mS fundamental that can be seen
> after demodulating and viewing on your radio audio scope or oscilloscope
> for verification of power line vs harmonics interferences.
>
> Get Outlook for iOS <https://aka.ms/o0ukef>
> ------------------------------
> *From:* adxa-bounces at mailman.qth.net <adxa-bounces at mailman.qth.net> on
> behalf of Dennis Schaefer <dennisw5rz at gmail.com>
> *Sent:* Sunday, December 29, 2024 5:56:37 PM
> *To:* Jay Bromley <jayw5jay at outlook.com>
> *Cc:* ADXA <ADXA at mailman.qth.net>
> *Subject:* Re: [ADXA] noise chasing
>
> Thanks, Jay - I can easily try that.  It does 432 and I can even use a
> small yagi to narrow things down.  The only problem is that the source is
> some unknown distance beyond the back fence, but if I can pick it up well
> enough to use the yagi to get a fix, that would be great.  I might be able
> to drive around to the other side and get a couple more fixes for
> triangulation even if I can't drive right up to the transformer and pole.
> I need to look at Google Earth and see just where the lines run over
> there.
>
> 73,
> Dennis
>
> On Sun, Dec 29, 2024 at 4:44 PM Jay Bromley <jayw5jay at outlook.com> wrote:
>
> Hi Dennis,
> Try the 817 on the highest band, I think it has 70 cm?  Anyway, many of
> the test gear these power companies use are 350 MHz receivers with built in
> attenuators.
>
> Stan K5VR loaned me his HT that has AM receive on 70cm and we found the
> problem just walking up and down the road.  Need to borrow it again.  Stan
> and I found problems up to ¼ to 1/2 mile away.  However, since Ozark has
> upgraded many of the power poles it never stays foxed for more than a few
> weeks!  They replaced every other pole or several in a roll.  The old poles
> have old hardware that was stressed during the upgrade.  Then you add all
> those new surge suppressors that are arching and you have a real mess.
> They say they need the protectors to keep the equipment from so much
> damage, but if they are bad and arching that isn't going to protect
> anything!  I like the idea or protection, but only if they are being
> maintained!
>
> My power company doesn't have the training or the expertise to really
> maintain the system.  I hate calling them, now on a first name basis with
> many of the employees and have their numbers in my contact list, hi.  Only
> once when I interfaced with one of their engineers did I feel like the
> problem was being addressed!
>
> Sadly, it is a fact of life we now live in.  Some of the better power
> companies are now using drones find broken hardware and that seems to be a
> game changer!
>
> 73 de jay/w5jay..
>
> ------------------------------
> *From:* adxa-bounces at mailman.qth.net <adxa-bounces at mailman.qth.net> on
> behalf of Dennis Schaefer <dennisw5rz at gmail.com>
> *Sent:* Sunday, December 29, 2024 2:36 PM
> *To:* ADXA <ADXA at mailman.qth.net>
> *Subject:* [ADXA] noise chasing
>
> Randy, W5ZJ, has given me some good advice about Pennant antennas and even
> sent me some ferrite binocular cores for matching transformers.  I'm in the
> process of figuring out how to orient the trial Pennant.  I thought my
> noise sources were mainly from N to E but weather kept me from getting out
> and doing much snooping.
>
> I rotated the yagis and then went out today with an FT-817 (handheld HF
> rig) and a 20M antenna.  I walked all around listening on 20 with good
> sensitivity and 80 with poor sensitivity because of the 20M antenna.  I
> verified what I was seeing on my yagis - the main noise source is to the
> South.  There is a house back there, about 700 feet away.   The poles and
> transformers to the N and E are quiet.  I didn't walk right up to the
> houses they are associated with, but those seem quiet also.
>
> The noise to the S has that raspy, pulsing noise I usually associate with
> power line noise or some kind of arc.  I know the noise is strong on HF and
> 6M but I'm limited on checking on 80 and 160.  I could attach something to
> the FT-817 that would be better on 80 but I think the source to the South
> is a broadband noise signal.
>
> The other hot spot is my electric meter, but I only detect noise when the
> 817's antenna is within a few inches.
>
> I also have a TinySA spectrum analyzer, which is a truly remarkable
> instrument for the size and price, but it doesn't seem to be sensitive
> enough for outside checking.  I can hold it up to a computer or router or
> wall wart and see the spurious emissions clearly but this is with the
> little antenna just inches away.  I haven't begun to analyze things
> associated with my house yet, but I will get to that.  I have a lot of
> FT-240-31's and I'm sure some will be needed.
>
> My inclination now is to put the Pennant with its null to the South.  It
> should cover EU and AS that way and I could get an idea how it works.  I
> may try to make it reversible but I want to keep it simple for now.
>
> 73,
> Dennis/RZ
>
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