[TenTec] Re: TWINCOM feedline?

AC5E@aol.com AC5E@aol.com
Thu, 17 Oct 2002 10:52:15 EDT


How does a radiating feedline cause TVI?  That depends on the individual 
case, but...

In my case a radiating feedline about 20 feet from the local CATV system's 
cable put enough energy into the CATV system to knock out the Playboy channel 
over most of our block.  The local bunny fanciers were outraged,  as were the 
late night porn movie fanciers. 

I had coax running almost in contact with the CATV cable with no interference 
to any channel - but any attempt to use the open wire line resulted in nasty 
telephone calls. While the SWR was well within 2:1  (a folded dipole radiator 
and 450 ohm wire)  and was actually less at the band edges, efforts to reduce 
feedline radiation proved fruitless. 

After some effort to get the CATV system to either replace their defective 
cable, or at least step up their signal enough to override the leakage, I 
gave it up.  The same antenna with a choke balun followed by a 4:1 balun at 
the feedpoint is completely TVI free. 

73 Pete Allen  AC5E