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Re: [TenTec] 95% Shield

To: "Discussion of Ten-Tec Equipment" <tentec@contesting.com>
Subject: Re: [TenTec] 95% Shield
From: "Ron Castro" <ronc@sonic.net>
Reply-to: Ron Castro <ronc@sonic.net>, Discussion of Ten-Tec Equipment <tentec@contesting.com>
Date: Thu, 15 May 2008 12:36:51 -0700
List-post: <tentec@contesting.com">mailto:tentec@contesting.com>
If the one mW is a harmonic or spurious signal radiated from your 
transmission line or antenna on the same frequency as the TV station your 
neighbor is watching, yes, it would cause TVI, however a good low-pass 
filter at the output of your transceiver or amp will mitigate that problem. 
I'm assuming here that the neighbor is using an outdoor antenna, not cable.

The other problem is that your fundamental signal is causing overload on the 
TV set, which is not your fault.  The fix for that, as Jim Brown, K9YC 
suggested, is to attenuate common-mode signals reaching the TV.  I have had 
great success killing some of the worst common-mode TVI/RFI wrapping a few 
turns of the cable and power line to the TV each around a ferrite torroid or 
rod to form a choke.

Another way to reduce common-mode signals in your neighbor's TV is to use an 
ICE model 472B TVI Filter: http://www.iceradioproducts.com/filtersrf.html#5 
.  I have used these with great success, although they cost $58 each.  Note 
that if the neighbor is using an external AV receiver, you may very well 
need common-mode chokes on each of the speaker leads.

         Ron  N6IE
      www.N6IE.com


----- Original Message ----- 
From: "Jim WA9YSD" <wa9ysd@yahoo.com>
To: <tentec@contesting.com>
Sent: Thursday, May 15, 2008 11:30 AM
Subject: Re: [TenTec] 95% Shield


> So what your saying is even ONE Milliwatt would create a problem with RFI. 
> So much for shielding in the real world.
>
> I want to build a glass house with no metal, and transmit 1 KW on the HF 
> bands with no RFI.  RRRRR never happen.
>
> Keep The Faith, Jim K9TF/WA9YSD
>
>
>
>
> _______________________________________________
> TenTec mailing list
> TenTec@contesting.com
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