Welcome
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
Quality,
yet, Inexpensive 1000 MHz Spectrum Analyzer.
The
Original MSA, mated with a laptop computer. Not pretty, but works
quite well.
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
Sprowls
If you
want to
build
your own Home-Brew 1000 MHz Spectrum Analyzer, you already have
half
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,
to be
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
Win10.
Previous visitors
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
does
not obsolete the Original MSA design. The Original MSA will
continue to be supported in the software.
The
title of this page and the opening paragraph seem to indicate
that the
Function of
the
MSA is a Spectrum Analyzer with
operation limited to 1000 MHz. This was my original concept
and design
goal. However,
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
of
construction. There are 3 Build Levels of the MSA.
Basic MSA,
Build Level 1: The
Basic
Modularized Spectrum
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:
0-1 GHz,
1-2 GHz, and 2-3 GHz (or higher using harmonic
mixing)
Frequency Resolution:
less than 3 Hz
Instantainous Dynamic range: greater
than 100 dB. Average 110 dB.
Sensitivity:
-20 dBm to -120 dBm
Resolution Bandwidth:
Optional, with Resolution
Bandwidth filter selection. When not used as an SA, the
Basic MSA can provide these other
Functions:
Logging
Voltmeter (future development with A to D Converter)
Frequency Sources:
Fixed, 64 MHz Clock Source,
50 ohm, square (Master Oscillator)
Variable,
1-1.5 GHz, 50 ohm, sine. Selectable in steps.
(PLO 2)
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,
0-32 MHz,
50 ohm, sine, 0.014 Hz resolution. (DDS 1)
MSA with Tracking
Generator, MSA/TG, Build
Level 2: Build Level 2 is the addition of 3
modules to add a Tracking
Generator to the Basic MSA. The following functions are
added: Spectrum
Analyzer with Signal Generator Spectrum
Analyzer with Tracking Generator
Normal Tracking
Generator, or
Offset Tracking
Generator, or
Reversed Tracking
Generator, with or without offset Scalar Network Analyzer Crystal
Analyzer, a Crystal Tester
Additional Frequency Sources:
Variable, 1-2 GHz,
50 ohm, sine, <3 Hz resolution. (PLO 3) CW or Swept DDS Signal Generator,
0-32 MHz,
50 ohm, sine, 0.014 Hz resolution. (DDS 3)
VNA,
Vector Network Analyzer, MSA/TG/VNA, Build Level 3: This is the addition of 2
more modules to the MSA/TG (Build Level 2) to
create a Phase
Measurement System. Vector Network Analyzer,
Transmission Vector Network Analyzer,
Reflection The VNA has the same Functions as
the Basic MSA and MSA/TG, plus the Functions: Filter
Analyzer RLC
Analysis, Circuit conversion Component
Meter, for measuring resistors, capacitors, inductors.
Coax Tester, a Transmission Line Analyzer Antenna Analyzer
MSA Requirements for the
Home Computer and its Software:
PC or Laptop Computer (any speed), with
USB 2 or LPT standard or enhanced
parallel
port (SPP, EPP). Monitor can be any
size, but MSA
software uses
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.
MSA Web Pages supporting the MSA
Project. Some are still in-work: Construction of the SLIM MSA,
a Construction Guide for integrating the MSA using Standardized Lab
Integration Modules. The Basic MSA, Tracking Generator
addition, and Vector Network Analyzer extension are covered. Specifications
for the SLIM MSA and links to pages for the
construction of the individual SLIMs. Construction Hints.
Hints on
constructing the SLIMs. It may save you a
lot of potential grief. Initial
Set-Up and Calibration of the MSA, including instructions for
downloading the software. Test-As-You-Build, A test procedure
for
SLIMs as they are built and integrated into the MSA. Testing the Integrated MSA, A
test procedure and troubleshooting guide for a fully integrated MSA. Control and
Operation
of
the MSA is common to all Build Levels of the MSA. A description of
screens, controls, and operation. Technical Analysis
of the MSA.
In-depth circuit analysis. Very
handy for troubleshooting the MSA. Temperature Testing of the MSA. Testing
the MSA/VNA for temperature induced error. In-work. SLIM Web
Page. The Standardized
Laboratory Integration Module
philosophy and links supporting the SLIMs. Coaxial Cavity Filter, description and
construction of a high-Q, 1013 MHz bandpass filter. USB control for the MSA. Using the
MSA to
Test Phase Noise of PLO 2, DDS 1 as a Low Phase Noise Sweep Source Using the DDS 1 to Sweep a Crystal Filter,
DDS 1 as a Tracking
Generator or Scalar Network Analyzer MSA
Archives,
old stuff no longer maintained. Use it, but many links don't
work. I will repair them as time permits. VNA
Operating Guide, by Sam Wetterlin
Other Web Sites supporting the MSA Project MSA
Builder's Group, for those interested in
sharing
ideas on
the MSA. There are many people in the process of building or
using the
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,
(mirrored) a
Gold
Mine of information supporting his
MSA/VNA, examples:
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.
OSL Standards.
Construction and explanation
for precision open, short, and load for use with the VNA.
Attenuators.
Precision fixed and switchable attenuators.
Reflection Bridges,
passive and active. For use with
the MSA/VNA.
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)
A
little about
me: My
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.
(end of page)