SmartSmith version 1.5.3 - now available at
http://www.qsl.net/w9dmk
This release incorporates the following major changes:
Main Window -
The main window has been shrunk to fit comfortably in an 800 x 600
display environment. The earlier releases were all designed for a 1024
x 768 (XGA) display environment, and users with older systems had
great difficulty in using the system on an 800 x 600 (SVGA) display.
In order to accomplish the re-sizing of the main window, the Smith
Chart display was reduced in size to 85% of its former size. The 9
different matching section controls were also removed from the main
window and given their own modal dialogue boxes that are exclusively
selected and shown floating above the main window only when in use.
Range of Control over Elements -
All matching section controls other than those involving lengths of
transmission line were extensively revised to provide the user with a
greater range of values. In this release, each control has a range of
5 decades and 50 discrete values within each decade. For example, the
Series Resistance matching section now starts at the value 0.1 ohm and
extends to a maximum value of 10000 ohms in 250 steps. Likewise, the
series capacitive reactance matching section starts at a value of 0.1
ohms and goes to a maximum value of 10000 ohms of capacitive
reactance, regardless of frequency. Each matching section control
displays its current setting both in ohms or milli-Siemens, as
appropriate, and in component values, such as microHenrys or
picoFarads. The exception is Series Resistance, which displays only in
ohms. Each control also displays its "dial" or "counter" setting
between 0 and 250.
The matching sections that employ transmission lines (Stub Open, Stub
Shorted, and Series Transmission Line) still display their value in
electrical degrees and in meters, as in previous releases. However,
note that only "Stub Open" and Serial Transmission Line display their
electrical length in degrees directly in the spin control display,
whereas the "Stub Shorted" displays its electrical degrees below the
spin control display along with the length in meters. This peculiarity
in "Stub Shorted" is in order to make "Stub Shorted" behave the same
as all other controls. Each of the other controls starts with a value
that has the least effect on the existing impedance situation spins
upwards to a value that has the greatest effect. In order to
accomplish that with a shorted stub, it is necessary to start the
shorted stub at its maximum (90 degrees) length and spin it up to its
shortest length (0 degrees).
Help File Improvements -
The Help File now includes topics on "Designing Pi Sections" and
"Quick Start". The "Quick Start" topic goes through a simple design of
an L-Section to match a high impedance, complex load to a 50 ohm
source. It also goes through a more difficult design using a series
transmission line section to create a match with a high impedance,
complex load and a 300 ohm line. The latter exercise is take directly
from Chapter 28 of the ARRL Antenna Book, 17th Edition.
Tnx and 73,
Bob, W9DMK, Dahlgren, VA
http://www.qsl.net/w9dmk