Quote:
Originally Posted by toxcrusadr
Thanks for the explanation. I finally get what balanced actually means.
I thought all TVs used 300 ohm flat cable up until cable tV started to take over in about the 1980s.
Now I'm curious what a common mode signal is.
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Common mode vs Differential
The above link gives a fairly good explanation.
If both conductors are picking up the same signal, current trying to go in the same direction in both, that's common mode. That gets cancelled at the balun for obvious reasons. But, with baluns at both ends and a straight run of 300 ohm twinlead you have a loop that can have current induced in it though magnetic induction if you don't put a few twists in it to cause it to cancel out.
That's not a very careful explanation, but I'm sure you get the idea.
It's easy enough to make the proper baluns, but it may not be worth the effort. If you do it would be interesting to hear the results.
John