[TowerTalk] Phase, Time, and Polarity -- Let's Get Our Words Straight

[jimlux]

Jim Brown wrote:
> On Fri, 22 Jan 2010 20:16:59 -0800, jimlux wrote:
> 
>> If you have a time delay between the two antennas (as opposed to a phase 
>> shift), then the time delay sets the angle, frequency independent. Since 
>> most folks use a hunk o' coax for the phasing, then you're good to go.
> 
> Actually, the coax provides a TIME offset, NOT phase shift. There is a 
> resulting phase shift from a TIME offset, that is proportional to 
> frequency. 

Yep..

> 
>> If you're using phase reversing (e.g. in phase, out of phase) then it 
>> doesn't work as well.
> 
> When you reverse the wires in a system, you are not changing PHASE, you 
> are changing the POLARITY. When you reverse the polarity, there is NO 
> change in time (or delay) or phase, but you invert the waveform, and the 
> signal is complex (fundamental plus harmonics, or carrier with 
> sidebands), the signal is inverted at ALL FREQUENCIES. 

Good point. I was careless.

In any case, phase reversing has a different sort of effect from a time 
delay cable.