[BC] Engineering Advice

[Mike McCarthy]

In this rare instance of Tom being serious...When it comes to antennas, 
there is so much bluster in the sales pitches that it can be very hard to 
discern the subtleties between the various design implementations. 
Especially from the lesser known companies trying to make inroads. This is 
where research becomes the key to achieving the goal of selecting the best 
antenna for THAT SPECIFIC installation.  Tom is right in his application of 
the word investment.  An antenna is an investment.  Which requires the same 
planning and research as the transmitter.

Until a few years ago, I didn't realize that one could define the FM bay 
spacing to anything desired without a special CP to achieve very specific 
vertical pattern results. Not just 1/2 and full.  The conditions and 
results can and will vary by location, terrain, and a host of other factors 
which are generally unique to a site. So spacing is a factor to be considered.

Granted, one can throw any full spaced x-bay antenna up and achieve a 
working low VSWR system.  "Working" being a relative term.  There are 
certain instances where you don't want a specific type of antenna or design 
practice...which would be a poor investment. And research will tell you that.

MM

At 09:11 AM 2/14/2009 -0500, Thomas G. Osenkowsky wrote
>If I am responsible for a project, be it an AM or FM
>antenna system design, transmitter or studio facility
>upgrade I like to obtain all possible information so I
>can make an informed decision for my client. My name
>will be on that project as will my reputation.
>
>Since we have a wide variety of people on the list with
>a wide range of experience it is helpful to solicit input
>from all of you. The fact that some experiences may
>conflict with one another is also informative. The
>choice of antenna bays vs element spacing, HAGL
>vs HAAT, etc. is a project that requires attention to
>specifics. Given the terrain, location(s) of the desired
>coverage, tower height limitations, transmitter power
>capability, and other factors is a selection that is
>unique to the circumstance. This must be carefully
>calculated to achieve the desired results.
>
>I prefer to tell a client he/she is investing, not spending
>money on a project. That is inclusive of my fee. I like
>my clients to get a positive return on their investments.
>
>Tom Osenkowsky, CPBE
>
> > >All I was trying to write is that when you are going to spend a large
> > >amount of money on the equipment, and installation, you need to get
> > >into some very specific discussions with people you can trust.