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Re: [TCML] TESLA COIL EMI or RFIhome electrical system.



Agree.  Once you are properly radiating (typically the transmission element having similar dimensions to wavelength) then it is 1/r2.  So spark gap noise (on the primary in the 100+MHz) is 1/r2, but emission for fundamental frequency of most coils is 1/r3.  

Interesting potential argument about where there is most emitted power, and what causes more interference, but I think we're both agreed this varies on a case by case basis, and that some line filtering plus distance is the best all round plan. (That and having neighbours who also love Tesla coils, and don't care about a bit of interference in exchange for a great lightning display!) 

-----Original Message-----
From: Ed [mailto:evp@xxxxxxxxxxx] 
Sent: 03 October 2016 18:49
To: Colin Tregenza Dancer <ctd@xxxxxxxxxxxxxx>; Tesla Coil Mailing List <tesla@xxxxxxxxxx>
Subject: Re: [TCML] TESLA COIL EMI or RFIhome electrical system.



On 10/3/2016 6:25 AM, Colin Tregenza Dancer via Tesla wrote:
> Absolutely agree that distance is key.
>
> Filtering helps direct conducted emissions, and shielding the power feed can significantly reduce pickup (and then conduction) from the coil, but they are not enough if the coil is physically close to other wiring/kit.  The electric field, and magnetic induction field from the output can always be a problem, but 1/r3 comes to our aid.
     For low frequency interference yes.  For VHF it's only 1/r2.

Ed
>
> Colin.
>
> -----Original Message-----
> From: Tesla [mailto:tesla-bounces@xxxxxxxxxx] On Behalf Of drieben@xxxxxxx
> Sent: 02 October 2016 03:16
> To: Colin Tregenza Dancer via Tesla <tesla@xxxxxxxxxx>
> Subject: Re: [TCML] TESLA COIL EMI or RFIhome electrical system.
>
> Hi Colin,
>
> While I do agree that proper filtering can go a long way toward significantly reducing the ill-effects of RFI/EMI kickbacks of the tank circuit into the power supply feed, I still maintain that it is nearly impossible to completely eliminate this problem, at least within the budget constraints of the typical hobby level coiler. I do utilize each of the precautionary measures that you cite to address the back feed of RFI/EMI into my supply (the rest of the electric/electronic appliances in my home), I do still have some issues with the TV in the house getting some interference and the electronic start fluorescent lights going “haywire” when I run my big pole pig driven SG coil. I have found that distance seems to be my best friend in the fight against the back feed of RF into my home’s electrical system. The physically further that the coil is set up from my house when I fire it, the less of a problem the RF back feed seems to be.
>
> I don’t have any personal experience with running my coil off of a generator, just the wall plug, so I can’t speak to the issue of RF problems with running it off of a generator..
>
> David
>
> Sent from Mail for Windows 10
>
> From: Colin Tregenza Dancer via Tesla
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