Thanks Tim for the response. I've asked where in the NEC this is stipulated
but haven't had a response yet. The funny thing about all this is Bob Heil
in a very early Ham Nation recommended exactly what I'm doing. It took me a
while to figure out why it works. My station has an AC safety ground it's
not in a manner that people are used to seeing.
When I started chasing down all my RFI problems I knew I had to think
differently. Following the handbook, W8JI's etc did nothing to remedy my
RFI. I have a small station, no tower etc. Just 100 WaaW as they say.
I realized I was going about this in the wrong direction. I want to stop
outside RFI from entering my equipment. Back in the day it was the other
way around - amateur RF got into other's equipment.
A lot of the grounding techniques were developed in the day when switch
mode anything or energy efficient stuff even existed. By figuring out the
large ground loop hidden in the walls I thought maybe a lot of common mode
RFI was coupling into this loop. I live near San Diego and the earth here
is rather poor so I postulated it was high enough impedance to effectively
not be of any use. When I split the AC ground a lot of that common mode
noise went away. It wasn't all gone so that's when I put ferrite on every
cable that attaches to my equipment. The end results were better than I
expected as seen in the video.
The one test I haven't done is to put the AC ground back into play and see
what happens. I will try that.
I know what I've done is not seen as a traditional solution of many ages of
amateur radio but desperate RFI times require desperate measures.
73! Mark KA6WKE
Website: https://www.ka6wke.net
On Tue, Feb 4, 2020, 19:20 Tim Duffy <k3lr@k3lr.com> wrote:
> Hello Mark:
>
>
>
> What you are doing (and suggesting others do) with the AC ground – to
> break it – is not right. It violates the NEC code and is very unsafe.
>
>
>
> Please refer to the NEC. What is posted here on the RFI reflector is
> viewed by thousands of hams. We must give proper (SAFE) advice.
>
>
>
> Please refer to K9YC’s on line work and to N0AX’s book. There is only ONE
> way – the right way.
>
>
>
> 73
>
> Tim K3LR
>
> RFI reflector founder and moderator.
>
>
>
>
>
>
>
> *From:* Mark Schoonover [mailto:mark@ka6wke.net]
> *Sent:* Tuesday, February 4, 2020 8:26 PM
> *To:* Tim Duffy
> *Cc:* jim@audiosystemsgroup.com; Amps
> *Subject:* Re: [Amps] Amp causing RFI
>
>
>
> There can be two paths to ground. One from the back of your equipment to
> the station ground then back to house ground. The other path is from the
> ground in the outlet back to breaker box to house ground then back to
> station ground. That creates a large loop depending on how much AC wiring
> involved.
>
>
>
> I use several of those three prong to two prong AC adapters to break the
> path in the AC ground leaving just one path to ground through station
> ground. All chassis grounds are connected to AC ground so electrical safety
> isn't compromised. Really cleaned up a lot of noise with my station.
>
>
>
> The main video about RFI on my website I drew it out on a whiteboard. It's
> about 2/3 of the video.
>
> 73! Mark KA6WKE
>
> Website: https://www.ka6wke.net
>
>
>
> On Tue, Feb 4, 2020, 16:32 Tim Duffy <k3lr@k3lr.com> wrote:
>
> Hello Mark,
>
> I am confused. What does a connection to earth ground have to do with
> ground
> loops?
>
> 73
> Tim K3LR
>
> -----Original Message-----
> From: Amps [mailto:amps-bounces@contesting.com] On Behalf Of Mark
> Schoonover
> Sent: Monday, February 3, 2020 11:04 PM
> To: jim@audiosystemsgroup.com
> Cc: Amps
> Subject: Re: [Amps] Amp causing RFI
>
> On Mon, Feb 3, 2020 at 7:57 PM Jim Brown <jim@audiosystemsgroup.com>
> wrote:
>
> > On 2/3/2020 7:48 PM, Alek Petkovic wrote:
> > > ndeed. It has also helped me and most ham friends I know on numerous
> > > occasions.
> > >
> > > Adding a few shallow buried wires to the ground rod has also worked
> well
> > > for me.
> >
> > Balderdash. The earth is not a sump into which noise, RFI, and other
> > trash is poured. Comments like this bring to mind the infinite number of
> > monkeys and typewriters producing Shakespeare.
> >
> > 73, Jim K9YC
> >
> >
> What having a decent ground does is eliminate the possibility of ground
> loops provided the ground is lifted from the third pin of the AC plug. I
> did a comprehensive RFI video on the subject and show how ground loops can
> happen and what to do to eliminate them. Quite possibly the #1 cause of
> RFI. You can watch the video in the link below.
> _______________________________________________
> Amps mailing list
> Amps@contesting.com
> http://lists.contesting.com/mailman/listinfo/amps
>
>
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