It's time for a word about objective vs. subjective opinions.
I once had a Mosley TA-33. I paid a lot of money for it (for me at the
time) and went to a lot of trouble to hang it on a tower, so I was
convinced it was great.
I moved, sold my TA-33 and tower. Put up a SteppIR DB18. Wow, what a
difference in apparent gain and front to back! Of course, the antenna cost
7x what the Mosley cost.
That's a subjective opinion. It's just what I thought.
I try to avoid spending money based on subjective opinions, but, being
human, I do.
When I buy a radio, for example, I always look at the measurements from the
ARRL labs and Sherwood Engineering, which contain objective data. I also
read subjective data like the reviews on eham.
After 45 years doing amateur radio and getting a engineering education,
I've learned to take antenna manufacturer's claims with a grain of salt.
For many years, QST would not run ads with specific claims for front to
back and gain - but manufacturers almost always provide them.
Claimed results may or may not be achieved in actual real world
installations. Height above ground, obstacles and even the Earth's magnetic
field can affect any installation. There's no standard environment for all
antennas to be tested in the same environment, but the claims are out
there, usually based on valid mathematical modeling. This provides a
reasonal basis for objective evaluation, in my opinion.
But some folks, including Mosley and G5RV, designed many of their antennas
back in the day before tools like EZNEC, had less accurate models, and
built and tested experimentally. So you can't expect the performance of
those antennas to be at par with a iterative design using modern tools.
The formal evaluations of antennas referenced elsewhere in this thread are
good indications as to the value and objectivity of manufacturer's claims.
If you're in the market for an antenna, purchasing one or more of those
reviews is money well spent.
Mosley survives because of subjective opinions and customer loyalty. You
can read those here in this thread. I'm happy they do survive, but hope
they continue to innovate - their mechanical designs are robust and sturdy.
Here's an article about what's subjective and what's objective. Remember,
if someone says that, objectively, your antenna is a Piece of Shot, they
may be objectively correct. But you may have achieved Honor Roll with it,
it obviously has some value to you, so don't take it personally.
Article link: http://www.diffen.com/difference/Objective_vs_Subjective
About my objectivity: I have no financial interest in any manufacturer of
antennas or publisher of ham radio information at all.
73,
Mickey N4MB
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