[TowerTalk] 135 foot dipole, 300 ohm twinlead

[Buck - N4PGW]

I had a 129 foot dipole fed with CATV coax.  It did ok, but where the
aluminum met the copper, it oxidized and I have been suffering with AM
broadcast band bleedover on all frequencies below 14 MHz.  I recently
replaced it with a 135 foot dipole fed by 300 ohm TV twinlead to my tuner on
which my IC-706 sits.  The problem I have now is TVI.  When I get the
antenna tuned and run more than 30 watts, the TV pictures turn red, green,
or blue.  We are on Cable TV and I cannot recall the last time I had TVI
other than when I operated 6 meters and the rig is sitting less than two
feet from my TV.  (the TVI now is all over the house.)  I don't know if it
is getting into neighbors homes at this time.

I figure I am getting less loss tuning that antenna with twinlead as opposed
to coax, but I have a piece of RG-8 foam I am thinking about feeding the
antenna with instead.  

Any suggestions or ideas?

thanks,
Buck
N4PGW