RE: NEC-LIST: A question about yagis raised by Zvi Frank

Ladies and Gents of NEC-LIST:

The information provided by Mr. Green is a most interesting historical
perspective from someone who was a pioneer in these studies. Thank you
for providing it.

Just as Australian publications are not always at always found at the
workbenches of the world's professional antenna engineers, those of
you who are not Radio Amateurs ("ham radio operators") may not be
familiar with the large body of amateur literature dealing with
Yagis. Pardon me if this sounds like an advertisement, but I would
like to refer you to "The ARRL Antenna Book." Let me hasten to
identify myself as the editor of the 17th and 18th Editions of this
book, and specifically as the author of Chapter 11 on HF Yagis.

The ARRL Antenna Book (with its accompanying IBM-PC diskette)
documents in Chapter 11 a good number of Yagi designs that have been
"optimized" for a suitable compromise of design criteria -- free-space
gain, pattern (expressed in terms of "worst-case front-to-rear ratio")
and SWR, all over specified frequency bandwidths (various amateur
frequency bands).

The diskette accompanying the book contains a lot of interesting
software, but two programs should be of interest to this particular
question: YA.EXE (Yagi Analysis, which analyzes a Yagi) and SCALE.EXE
(which allows the operator to scale a design optimized for a
particular frequency band to other frequencies and/or design
parameters, such as aluminum tubing tapering schedules).

The bundled diskette contains some 80+ HF Yagi designs, each of which
is an ASCII file that can be modified using an ASCII editor. Chapter
18 in the book deals with VHF and UHF antenna designs, including a
number of optimized Yagi designs that can easily meet the design
criteria the original questioner, Mr. Zavri Frank, had (14 to 15 dBi
free-space gain). These designs can also be evaluated using the YA.EXE
program, although the user will have to keyboard the entries manually
because they are not included in the sample files on the diskette.

The ARRL Antenna Book is more than 800 pages long and represents a
tremendous value because it is purposely priced to suit the notably
frugal habits of radio amateurs. The retail price is $30, including
the afore-mentioned software. In this day where a college textbook can
easily cost $80 to $100, this is a real bargain, in my opinion. Check
out the web site:

http://www.arrl.org under Products.

Sorry for what could be considered a somewhat blatant advertisement,
but I hope the group might appreciate the information.

Regards (or "73," as we radio amateurs say),

R. Dean Straw, N6BV
Senior Assistant Technical Editor, ARRL (The American Radio Relay League)
Received on Tue Apr 20 1999 - 16:08:58 EDT