[TowerTalk] In phase?

[Jim Brown]

On 11/15/2024 2:48 PM, Don Moman VE6JY wrote:
> The S meter extension available on many, maybe all of the ~1000  KIWI
> remote receivers around the world would give you a faster and better
> answer.  I use it all the time to evaluate similar antenna levels.
> http://rx.linkfanel.net/   No software needed, just connect in Chrome or
> similar browser.

Hi Stan,

Yes, remote receivers will tell you whether you're louder or weaker, but 
they won't tell you anything about phase relationships, because they 
don't tell you what vertical angle is getting you there. :)

A method that MIGHT be useful is to do your switching, and with AGC off, 
note which is louder for a lot of signals and paths, and compare that 
with your years of experience.

I've used the RBN to compare two antennas on 160M and gotten VERY good 
data by averaging a LOT of data over multiple nights of disciplined CQs, 
using my own call for one antenna, the club's call for the other. W6GJB 
did the same for two 80M antennas. In analyzing the data, plotted the 
difference between the two antennas vs distance. One antenna was an 
inverted V, the other a home brew vertical that we had designed together.

My situation was more complex, because one antenna was a Tee vertical, 
the other was a vertical wire fed from the base with elevated radials, 
sloping away from a 120 ft tower that acts as a reflector, so I analyzed 
data not by distance, but by reports from specific stations. And to take 
varying propagation into account, I did this for a half-dozen nights.

What my data told me was that the dense redwoods surrounding it were 
subtracting about 9 dB from the 2-3 dB that NEC predicted for the 
antenna. (The Tee vertical was about 200 ft away, and at the center of a 
large clearing for the house and shack. A few months later, I got an 
email from a ham retired from doing complex models for a major aircraft 
mfr, using software that could model the trees. His model predicted that 
amount of attenuation!


73, Jim K9YC