[TowerTalk] Measure / Check phase difference between two antennas?

[john at kk9a.com]

Regarding your " The last question is a real use case"  I believe that Yagi
phasing is not super critical.  Your phasing between two dissimilar Yagis
may be off but close enough for the stack to still work.  This should be
easy to model.

John KK9A


George Fremin III K5TR wrote:

I have posed this question to a number of people over the last few years -
and I have gotten some interesting ideas but I am not sure any of them have
provided a simple or repeatable way of making such a measurement. I have not
tried any of they yet but I think I am getting to that point.

So, I thought I would cast a larger net. 

On the simple side of things - if I have two antennas - lets say verticals
at some distance from each other with coax coming from them is there some
way to measure the phase difference?  Could I get some value out so that I
know how much delay I need to add to one to get them in phase for a given
signal?

Or lets say I have two yagis on a tower fed with coax and I would like to
verify they are in phase or at least close - can I measure this in some way?

What if I have say a 48 foot boom 10m yagi and a 24 ft boom 10m yagi on a
tower at 60ft over 30ft.  If there a way for me to measure the phase
difference? 

The last question is a real use case - and on the air use of this antenna
seems to show that I might have lucked into these antennas being in phase -
at least they work better together for EU and the USA.  But it would be nice
to repeat this luck or measure it.  

It would be nice if this did not require $100k in test equipment. 


George Fremin III
K5TR