to the MSA Web Site,
the Modularized Spectrum Analyzer Interested
in owning your own RF Spectrum Analyzer ?
This site is dedicated as a Home Experimenter's Guide to building a
yet, Inexpensive 1000 MHz Spectrum Analyzer.
Original MSA, mated with a laptop computer. Not pretty, but works
The newer version, the SLIM MSA. Same concept, but constructed
using Standardized Laboratory Integration Modules, SLIM's. Updated Aug.
11, 2017 Updated
software to Version 118. Download software from Initial
Set-Up and Calibration of the MSA The
MSA project was started in Jan,
2001 and has evolved under several titles. By Scotty
your own Home-Brew 1000 MHz Spectrum Analyzer, you already have
of it completed. That half is the computer
you are using to read this. The processors and displays are very
expensive portions of modern spectrum analyzers, and those
functions can be replaced by your home computer. The computer's
monitor is the
Spectrum Analyzer's display. The other half is the MSA hardware,
constructed (as seen in the photos).
The MSA Software is free to download. It will
operate on any computer with a parallel port, USB 2, or USB3 and
any Microsoft Windows platform. USB
operation has been tested using Win ME, Win XP, Win7, Win8, and
to this Site will notice significant changes. I have deleted most
references to previous versions of the MSA and will concentrate on the
MSA using SLIMs, Standardized Laboratory Integration Modules. The
previous designs and web pages are retained in the MSA Archives, for those who need the
references. The SLIM MSA
not obsolete the Original MSA design. The Original MSA will
continue to be supported in the software.
title of this page and the opening paragraph seem to indicate
MSA is a Spectrum Analyzer with
operation limited to 1000 MHz. This was my original concept
software and hardware additions have allowed the MSA to provide many
more Functions than just that of a Spectrum Analyzer. The Functions
depend upon the level
construction. There are 3 Build Levels of the MSA.
Build Level 1: The
Analyzer (Level 1) is the core of the MSA Project It
is comprised of 11
modules and is common to all
higher levels of construction. Its basic function is that of a Spectrum Analyzer,
with these specifications:
3 band ranges:
1-2 GHz, and 2-3 GHz (or higher using harmonic
less than 3 Hz
Instantainous Dynamic range: greater
than 100 dB. Average 110 dB.
-20 dBm to -120 dBm
Optional, with Resolution
Bandwidth filter selection. When not used as an SA, the
Basic MSA can provide these other
Voltmeter (future development with A to D Converter)
Fixed, 64 MHz Clock Source,
50 ohm, square (Master Oscillator)
1-1.5 GHz, 50 ohm, sine. Selectable in steps.
Variable, 1-2 GHz,
50 ohm, sine, <3 Hz resolution. (PLO 1)
Variable, 0-1 GHz,
50 ohm, sine, <3 Hz resolution. (PLO 1 - PLO 2)
Variable, 2-3 GHz,
50 ohm, sine, <3 Hz resolution. (PLO 1 + PLO 2) CW or Swept DDS Signal Generator,
50 ohm, sine, 0.014 Hz resolution. (DDS 1)
MSA Requirements for the
Home Computer and its Software:
PC or Laptop Computer (any speed), with
USB 2 or LPT standard or enhanced
port (SPP, EPP). Monitor can be any
size, but MSA
800 by 600 pixel resolution. Windows 98 or later. MSA
software is executable, but builders
who wish to modify the MSA software will need Liberty Basic 4.03.
The Liberty Basic is
free, but it will nag you to buy it. Go visit their web
site at www.libertybasic.com.
Other Web Sites supporting the MSA Project MSA
Builder's Group, for those interested in
the MSA. There are many people in the process of building or
MSA and can offer suggestions and comments. This is a Yahoo Group
page and you are welcome to join and contribute. Sam Wetterlin's Site,
Mine of information supporting his
Wide Band Leveler.
An AGC Amplifier
with constant output amplitude, for calibrating the MSA.
1 MHz Calibration
Source. Sine and Square Wave
Generator, for calibrating the MSA.
Construction and explanation
for precision open, short, and load for use with the VNA.
Precision fixed and switchable attenuators.
passive and active. For use with
Test Fixtures. Series and Shunt
Test Fixtures. Used as
test bridges with the MSA.
Sam has written several documents supporting his
MSA/VNA. I will
refer to many of them: House Dillon Site,
pages of his MSA construction. hackaday.com,
includes videos of testing SLIM modules Kevin
Jardine - VK2KVJ, an excellent photo review of his MSA wiki.electrolab.fr/Projets:Lab:2011:SA-Scotty,
web site for group of MSA builders (in French)
name is Scotty Sprowls. I am a retired RF Design Engineer from
E-Systems / Raytheon. Although I am not an Amateur Radio
Operator, I repaired radios as a hobby. My frustration in
tuning cavity filters in diplexers drove me
to create this Spectrum Analyzer to aid me. Click here to contact me.
I will try to
answer your questions or comments as soon as possible.
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