[TenTec] 450 Ohm feedline

[ac5e at comcast.net]

Well, you learn something every day. But I 'spect my first Elmer, Old Hardman, would have a good belly laugh about twisting the line to keep it balanced. Back in '47 we were told that the two halves of a doublet antenna could not be exactly identical in length and siting so doublets were inherently unbalanced. And of course, since the load must be unbalanced the transmission must also be unbalanced. 

According to then established doctrine, open wire line, and later TV twinlead, was to be twisted to reduce automobile ignition noise and other impulse noise pickup. Radio Craft had a big illustrated writeup showing Kukla, Fran, and Ollie eaten up with ignition noise that went away when the twinlead was twisted at a one turn in three feet rate.  

Of ocurse, at that time the closest TV station was in Chicago so that didn't make much of an impression on us. Later, when the idiot boxes became common I found twisting the line sometimes made a difference - but not when the source of the noise was close to the transmission line. 

73  Pete Allen  AC5E
--
Never squat with your spurs on