Tom, your comparison results are interesting, but like you stated, from an
experimental design and data analysis viewpoint, you might be getting some
interaction effects and confounding of the data. That is why the results
when running a computer program that runs simulations of various antenna
designs and configurations can produce very different results from what you
get when putting up the antenna in the real world! <lol> 

Ron, K8HSY

-----Original Message-----
From: For blind ham radio operators [mailto:[log in to unmask]]
On Behalf Of Tom Behler
Sent: Wednesday, November 26, 2014 8:14 PM
To: [log in to unmask]
Subject: Re: SWR, antenna tuners, and reflected power

Ron:

Yes, I've done a number of comparisons, but not on all bands.

To summarize:

The Cobra performs better on 80 meters, and about equal to the Alpha Delta
on 20 meters.

The cobra does ok on 160 meters, while the Alpha Delta does not tune at all,
which is what I'd expect.


The Alpha Delta is far superior to the Cobra on 40 meters, for reasons I
don't quite understand, since the cobra is supposed to tune on 40 and do
reasonably well.

The Alpha Delta does better than the Cobra on both 15 and 10 meters.

I haven't done systematic comparisons between the two antennas on the WARC
bands.

I think my results are confounded a bit by some variables related to my
instalations, such as some coupling between the antennas, and possibly other
nearby elements on our house and garage.  But, I haven't totally unraveled
all of those mysteries yet.

The bottom line, I guess is that there are some clear improvements that I
can probably make to things here.  At the same time, though, I do seem to
get out reasonably well on most bands with one antenna or the other.

Tom Behler: KB8TYJ


-----Original Message-----
From: For blind ham radio operators [mailto:[log in to unmask]]
On Behalf Of Dr. Ronald E. Milliman]\\`
Sent: Wednesday, November 26, 2014 5:53 PM
To: [log in to unmask]
Subject: Re: SWR, antenna tuners, and reflected power

Tom, have you ever made a comparison of the Cobra ultralite senior antenna
to your Alpha Delta DXCC nulti-band dipole? That is, when talking to a
station using one of the two antennas, have you ever switched to the other
one to see which one performed best? Have you conducted such a comparison on
each band? If so, what were your results? 

Ron, K8HSY