Bill, KM9P, raises an interesting point on antenna design, and the
use of computer simulation. I'm no expert on antennas, but I did take
one course in grad school and expect to install Wires/NEC in my laptop.
However, the bread and butter of my employment fot the past 20+ years
has been in optical design/engineering which is done alomst exclusively
thru computer modeling on the other end of the E-M spectrum. I that
- In that realm, there are many softwrae packages at varying levels of
complexity which model different facets of the phemonia differently.
It is not uncommon to find inexperienced "technical" people redefining
the lwas of physics based on their findings on some computer program.
If left unchecked, the world would be filled with multitudes of hardware
that does not work what-so-ever.
In the realm where I work, it is not uncommon to have other people duplicate
one's finding on "other" software packages. It is not uncommon to even
have to write your own software to model unigue configurations. It is not
uncommon to place NO FAITH in the results of any computer output unless
one understand what the code is modeling, and what it's limitations are.
The first test of a computer model is not in the the fabricated hardware,
but rather a basic SANITY CHECK by other "experts". Without this, we only
have a hypothesis.
73, alan N2ALE/6
aka ames@force.decnet.lockheed.com
>From Steve Fraasch <sfraasch@ATK.COM> Tue Aug 30 20:10:00 1994
From: Steve Fraasch <sfraasch@ATK.COM> (Steve Fraasch)
Subject: PIN Diode Reference
Message-ID: <2E638433@msm.ATK.COM>
I wrote before:
> Kevin, the most usual (How about useful?) reference I have found is the
"PIN Diode Designer's
> Handbook and Catalog," by Unitrode, Lexingon, MA, a PIN diode
manufacturer.
Steve Kelly, KC7EM, asks:
Do you have an address or phone number for ordering this catalog?
Yes! Unitrode PIN line was bought by Microsemi. I talked to Mr. Bill
Dougherty, 508-670-9086 (ext 3138), their applications engineer. He says
that Microsemi just finished re-writing the new "PIN Designers' Handbook",
and is publishing 10,000 copies this fall. Call him directly to obtain a
copy. He also says there are 2 application notes (MPD-101, MPD-102), with
more coming. Recent articles appear in Dec. 93 "Microwaves & RF," as well
as numerous articles in "RF Design." Lately they have been developing
diodes with longer carrier lifetimes to permit lower freq operation (700 Khz
multi-KW switching).
So - there you have it. Now that multi-KW 160m amp T/R relay is possible
with PINs (Oh no! Here we go again with the big amplifiers, GAS, NITRO, evil
hams, etc.). I'll re-state in politically correct fashion: that low-impact,
contest-equalized, non-offensive, Sierra Club, Green Peace, PETA and
Clinton-approved QRP 160 meter rig T/R relay is now possible with PINs.
73,
Steve Fraasch, K0SF
Minnepolis, MN
sfraasch@atk.com
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