[TowerTalk] New antenna?

[Jim Brown]

Remember that these guys were using a well chosen test range -- they 
didn't have access to MIL grade range, and they used methods to take 
their range into account.  When you're making measurements by 
substitution, the use of calibrated observation antennas doesn't matter. 
And the difference between their range, and an idealized range, doesn't 
matter much, thanks to their methods. It's been 15 years since I studied 
their reports, but back then, I couldn't see any holes in their methods. 
Note that the baseline for gain dBd was a dipole at the location of the 
DUT, and I think I recall that location was chosen for uniform ground 
characteristics.

Further, if you read N6BT's writing about antennas and N0AX's antenna 
reviews, it's clear that both think about how vertical directivity and 
mounting height interact.

As to the Moseley results -- I don't see anything in their setup that 
accounts for a 6dB difference from one antenna to another. Further, note 
that results for the other antennas clustered in a far more reasonable 
manner. Further -- the smaller tribander was less inferior to the others 
-- more like 3dB.

Another VERY important point. The design issues are maintaining vertical 
and horizontal directivity over the width of the ham band in question. 
That's a LOT of variables to control. To understand this, we only need 
to try modeling simple Yagis in competent software. I've never taken the 
effort to go beyond Dean Straw's YW.

I'm told those with the EE chops to know that Brian Beasley has taken 
this to a far higher level, but his software has been unavailable for 
decades. And I haven't gone into it, because my real very tall redwoods 
favor high dipoles for the lower HF bands, and it took me three years 
and advice from K7LXC to find a place in that dense redwood forest where 
I could swing something as small as the straight 3-el SteppIR!

73, Jim K9YC

On 3/31/2026 1:04 AM, vk3od--- via TowerTalk wrote:
> He used calibrated antennas to make these measurements long before N0AX and K7LXC whose procedure did not use calibrated measuring antennas on a controlled range.