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  The Motorola® Spectra™
Radio Index Page

Including non-mobile Spectra-based products
with some Astro Spectra stuff thrown in

Maintained by Robert W. Meister WA1MIK


This page has undergone a major reorganization.
Everything is all still here; items just got moved.
Use your browser's SEARCH function
to find things, as they're now grouped better.
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If you don't see what you are looking for, don't forget to check Mike Blenderman's extensive Spectra site here.

Background, Introductory, and General Information:

. Motorola Spectra Introductory Information You should read this article before any of the other articles here in this section. It has an introduction to the Motorola Spectra radios, with background, history, some model-specific information, photos, and other miscellaneous tidbits.
. Intro to Spectra Radio Configurations by Robert W. Meister WA1MIK
A quick run-through of the control heads and radio installation and mounting options.
. The Spectra Desktop Station by Robert W. Meister WA1MIK
What's inside, model number info, configuration switch settings, rear connectors, etc.
. Setting Up and Using Multiple Coded Squelch (MPL) by Robert W. Meister WA1MIK
The steps you need to do with the programming software to activate MPL, and how to use it.
. Why a 900 MHz Spectra Won't Receive at 902 MHz and What You Can't Do About It by Robert W. Meister WA1MIK
Spectras are great radios but they can't receive 902 MHz unless you have some specialized equipment and do a lot of work.
. Spectra Error Codes by Robert W. Meister WA1MIK
A compilation of FAIL and ERROR codes that can be displayed by Spectra radios.
. A Comparison of Old and New Spectra Circuit Boards by Robert W. Meister WA1MIK
Photos and lists of the major differences between old and new versions of many Spectra circuit boards.
. A List of Spectra Module (Board) Numbers by Robert W. Meister WA1MIK
A summary of info extracted from a number of service manuals.
. Identifying Spectra Frequency Ranges / Splits by Mike Morris WA6ILQ
Photos and things to look for to help identify the range or band split of your radio.

Brochures and Manuals:

. Spectra Sales Brochure 674 kB PDF
An original Motorola catalog sheet with abbreviated specifications.
. Spectra Motorcycle Spec Sheet 189 kB PDF
An original Motorola spec sheet with photos and abbreviated specifications.
. Spectra Conventional Radio System Operator's Manual 4.1 MB PDF
. Spectra Privacy-Plus Radio System Operator's Manual 2.3 MB PDF
. Spectra SmartNet Radio System Operator's Manual 4.1 MB PDF
. Spectra Parts Catalog 1 MB PDF
. Another Spectra Parts Catalog 240 kB PDF
. Info on the new Motorola Railroad Locomotive Cab Radio based on the Astro Spectra 140 kB PDF
. Spectra Clean-Cab Railroad Radio Operator's Manual 780 kB PDF
. Direct Entry Keyboard (DEK) schematic 614 kB PDF
. Hand-Held Control Head Single and Dual Radio Instruction Manual 2.8 MB PDF
Introductory information only for Option W845ASSP (dual radio) and Option W845AUSP (single radio) with HHCH, SIU, security boxes, etc. Scanned by WA1MIK. Goes with the dual radio article below.
. Astro Digital Spectra Consolette Instruction Manual 2.6 MB PDF
. Spectra 25/40 watt UHF Basic Service Manual 4.4 MB PDF
Scanned by Tim Owen KF7EUO.
. Astro Digital Spectra Basic Service Manual 2.5 MB PDF
. Astro Digital Spectra Detailed Service Manual, part 1 of 4 Chapters 1-6. 2.5 MB PDF
. Astro Digital Spectra Detailed Service Manual, part 2 of 4 Chapter 7, pages 1-25. 3.7 MB PDF
. Astro Digital Spectra Detailed Service Manual, part 3 of 4 Chapter 7, pages 26-48. 8.1 MB PDF
. Astro Digital Spectra Detailed Service Manual, part 4 of 4 Chapter 7, pages 49-134 and appendices. 8.4 MB PDF
. Astro Digital Spectra Detailed Service Manual 20.5 MB PDF
The entire manual as one file. Note that the regular Spectra radio shares the same Power Amplifier (PA), Voltage-Controlled Oscillator (VCO), and Receiver Front End (RXFE). Much of the RF Board is similar. The command board is totally different. Unfortunately the control heads are in a separate manual.

Radio and Equipment Modification Articles:

. Spectra Dual Radio Configuration Procedure By Josh Wallace KD5QCZ.
This article goes with the Hand-Held Control Head (HHCH) PDF file above.
. Recapping the Spectra Mobile (a.k.a. the Time-Bomb Capacitors) by Robert W. Meister WA1MIK
As the Spectras have been discontinued since the mid to late 1990s, all of them are now over 15 years old. All of the original surface-mount electrolytic caps MUST BE REPLACED or you risk doing serious damage to the radio.
. Recapping the Systems 9000 Control Head by Mark Tomany N9WYS
The same timb-bomb capacitors exist in these heads as well.
. Recapping/Refurbishing the Spectra Mobile by David Rudd AI4JI (off-site link)
A well-written article with lots of photographs. He sells capacitor kits as well.
. Build Your Own Spectra Low-power and Medium-power Programming Cable by Robert W. Meister WA1MIK
. Build a Spectra Low-power and Medium-power DC Power Cable with Ignition Control by Robert W. Meister WA1MIK
. How to Hex Edit the Spectra RSS to Enable 900 MHz Amateur Frequencies by Robert W. Meister WA1MIK
. Spectra 900 MHz VCO Modification by Robert W. Meister WA1MIK
Make the VCO operate in the 902-928 MHz range.
. Spectra UHF VCO Modification by VK3KBC (off-site link)
Make the VCO operate in the 440-450 MHz range.
. Adding a Preamp to a UHF Spectra Radio by Robert W. Meister WA1MIK
Add about a dozen parts and you've got a more sensitive receiver. People are selling kits to do this mod on ebay, of course.
. Miscellaneous Spectra Topics by Robert W. Meister WA1MIK
Hints and kinks that may make your Spectra radio more useful to you.
. Spectra Hacks (Bitbanging) by James S. Vooght K2JSV
Some key locations and values that can make the radio do what you want it to do.
. Some notes on Replacing the Spectra MLM by Alex Cobleigh K6LPG

Interfacing Articles:

. Interfacing External Equipment to the Spectra Mobile Radio by Robert W. Meister WA1MIK
Signals that are available on the connectors accessible from inside and outside the radio.
. One approach to adding a COR Signal to the Spectra DB-15 Accessory Connector By Nick Markovich N2XFX
Spectras are notably difficult to get much-needed signals out of. Here's one way.
. Spectra Control Head Ignition Jumper Information by Robert W. Meister WA1MIK
. Spectra Dash-mount Control Head Interconnect Boards by Robert W. Meister WA1MIK
. An Extension Cable for Repairing Dash-mount Control Heads by Robert W. Meister WA1MIK
For those of you that repair your own equipment, this handy accessory lets you get to the control head while it's connected to the radio.
. Spectra Command Board Jumpers: Location and Function by Robert W. Meister WA1MIK
. Spectra Command Board to PA and Accessory Jack Cables by Robert W. Meister WA1MIK


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This page was created in 2006.
This page was last updated on

Motorola, Spectra, Astro Spectra and a lot of other terms are registered trademarks/servicemarks of Motorola Inc.

This web page, this web site, the information presented in and on its pages and in these modifications and conversions is © Copyrighted 1995 and (date of last update) by Kevin Custer W3KKC and multiple originating authors. All Rights Reserved, including that of paper and web publication elsewhere.