K6CCC's truck control group (looking down at the console from head height)... From the top is a MCS2000 on 900 MHz (the shop radio), a Syntor X9000 on 800 MHz (using a type 9 head), three Spectras on 482-512 MHz, 450-482 MHz (both with type 7 heads), and a 146-174 MHz on a type 5 head. To the right are a pair of Midland Syntechs on low band. The Syntor, Spectras and Midlands are used for state and local gov't, law enforcement and fire communications. Amateur radio communications utilize a few frequencies in the high band Spectra plus an overhead-mounted Kenwood 742 on 220 MHz, 440 MHz and 1200 MHz. The truck in the photo is a 1986 Toyota pickup that was recently retired after 300,000 miles. The radios are going into a new truck.

FAQs not answered / handled:
1) How to use the wrong head on a radio (i.e. using an A5 head on an A4 radio, or an A4 head on an A7 radio, etc). Also, how to straighten out a mismatch (This is a candidate for a bit banging article on how to change the control head type, from what I've been told it just requires changing the model number in the MLM and the Command board in two different memory locations and you're all set).
2)How to crack the model number / ID number... Full, current model number information doesn't seem to be available. There is a partial chart below that has been reverse engineered. Some spectras have both an "ID Number" and a new format "Model Number" in the format of "TA9KX-068W" and nobody seems ot have a breakdown chart on that format number.
3) There is an early Spectra and a later Spectra II, commonly called the "E-Series". Apparently the latter gives SmartZone capability for trunking systems and uses a different command board which does NOT have a separate MLM (memory logic module).

Mike Blenderman K7IC has a very extensive web site on Spectras, and there is no point in duplicating his effort here at Repeater-Builder. This web page is only going to cover topics that are not covered at Mike's site. I really suggest that you go to Mike's site first (and bookmark it) as the topics there include:

• Model number breakdown - for example, the 9th character of model number is the radio type:
  A=Conventional,
  B=Privacy Plus trunking,
  C=SmartNet trunking,
  D=StarSite,
  E=Enhanced.
  The primary difference between the A, B, and C series heads is the legends on some of the buttons; some are useful only for trunking.
• Manuals (both Basic and Detailed Service Manuals plus RSS manuals) - including which manual part numbers are the good ones to order
• Single Radio Drawer Mobile Configurations
• Control Heads (including the Hand Held Control Heads)
• Remote Mount / Trunk Mount Configurations
• Programming Tips
• Systems 9000
• Cables (both vehicle and motorcycle)
• Accessory Cable Pin Out
• Direct Entry Keyboards / DEKs - a fancy name for a box with pushbutton switches on it, that is used in conjunction with a X-9000 or Spectra radio. The buttons can be programmed to do many things, like activate various siren modes, send status information, or send specific messages, either via MDC1200 or trunking data. DEKs only work with a remote mount control head that has a Systems 9000 VIP (Vehicle Interface Port) connector, which with the Spectra usually limits you to a A9 head (the large one). The code plug must also allow the DEK to work (i.e. enabled in RSS). If you have an A4, A5 or A7 type then it may not work with a DEK. The maximum number of DEKs can be attached to the radio is three. They use the serial communications bus on the accessory jack and multiple units just daisy-chain together. The buttons and status value or message text are programmed via RSS in the control head section. Not all radios support DEKs. The DEK is a appliance for the control head and will not substitute for it. A DEK is only a very simple hardware interface that takes parallel pins and translates them to a primitive synchronous serial data stream the control head can use. All the other stuff like status messages and such is all in the RSS / code plug software. There is no way to "program" something as simple as the DEK hardware itself.
• Parts and Accessories
• Spectra Radio Circuit Boards
• Remote Mount Kits
• Accessories
• Parts for Control Heads, DEKs and Speakers
• DPL / DCS Information
• Surplus Parts Guide

From a ham's point of view, the A7 radio is probably the most desirable, as it's a (usually) 128 channel conventional radio (i.e. not trunked) and has the 12-button 8-character display control panel / control head. The A5 is the second choice, the A4 has the volume and mode knobs. If you are going to use a remote mount radio (i.e. the radio chassis is in the trunk), and have the dash space, then the A9 control head may interest you as it has 3 more characters on the head display plus you can use a DEK. Radios equipped with a type 7 and type 9 heads will generate 12-button DTMF, there never was a 16-button DTMF model made (to be precise, the command board generates the DTMF, but unless you have the right head it won't work). If you need 16-button DTMF then use a Motorola touchtone microphone and modify it as per the Jim Reese WD5IYT article (on the Motorola index page), or use a Midland or Johnson 16-button microphone and modify it for the Motorola microphone circuitry (and with a Spectra microphone cable and plug).

Spectra Model Chart (partial)

Sample model number: D44ZXA5JC7AK D 4 4 Z X A Radio Type Power Level Band Split Unknown System Operation Supply Voltage D Dash 1 <10 W 1 Low Band VHF F ? G Trunking A 12v [1] L Consolette 2 15 W 2 Mid Band VHF K ? M Conventional   M Motorcycle 3 30 W 3 High Band VHF V ? X SecureNet T Trunk 4 40 W 4 UHF Z ?   Z Special 6 75 W 5 800 MHz     7 100 W 7 900 MHz 8 110 W If anyone has the breakdown of the fourth column ("Unknown" in the table above), we'd appreciate the information. 5 J C 7 A K Operational Mode Model Specific Control Version Control Type Version Package 5 Trunking J Model Specific A Conventional 2 Limited (rare) A K [4] 7 Conventional   B Privacy Plus 3 HHCH [2] B H [5]   C SmartNet 4 Rotary C N [6] D StarSite 5 Standard (3 Button) D   E Note [3] 7 Expanded (12 Button) E   8 Expanded Control Station   9 Systems 9000

[1] Positive or negative ground.
[2] HHCH = Hand Held Control Head.
[3] Enhanced or SmartZone, depending on which book you read.
[4] Shipped with the standard mobile installation kit
[5] Shipped with the standard mobile installation kit except that the microphone and hangup clip are replaced with a handset and a handset hangup cup (common on railroad radios, transit busses, subway cars, and mountain cable cars).
[6] Warranty replacement - Shipped with no accessories (just a radio in a plastic bag in a padded cardboard box).

The following table was extracted from the Feature Matrixes in the Spectra 900/9000 Basic Service Manual, 6880101W37-C, for 4, 12, and 30 watt, 900 MHz mobile radios. Entries in the table with no revision letter came from the matrixes in the front of the manual. Entries with a revision letter (A, B, C, D, or E) came from an appendix that has additional feature matrixes based on the 11th character of the radio's model number. The 12th (last) character is always 'K' in these charts.

• "Head" column is the 9th and 10th characters in the 12-character model number (the "Control Version" and "Control Type" columns in the above table).
• "Rev." is the 11th character in the 12-character model number. A "#" indicates no revision letter.
• "Conv." is the number of conventional channels or modes.
• "Sys." is the number of trunking systems.
• "Flt." is the number of trunking sub-fleets per system.

Head	Rev.	Conv.	Sys.	Flt.
A5	#	128	0	0
A5	A, B, C	32	0	0
A7	#	128	0	0
A7	A, B, C	64	0	0
A9	#	128	0	0
B2	#, A, B	0	2	2
B5	#	10	10	10
B5	A, B	0	3	8
B5	C, D	1	6	8
B5	E	10	10	10
B5	F	128	10	10
B7	#	10	15	10
B7	A, B	0	8	8
B7	C, D	10	8	8
B7	E	10	15	10
B9	#	10	15	15
B9	A, B, C, D	10	8	8
B9	E	10	15	10
C2	#, A, B, C	10	8	8
C5	#, A, B, C	10	8	8
C7	#	10	15	16
C9	#	10	15	16

The 9th character specifies the trunking/coding style:

• Ax radios are conventional only.
• Bx radios are Privacy-Plus.
• Cx radios are SmartNet.
• Ex radios are SmartZone.

The 10th character specifies the type of control head. All of these control heads have rocker buttons for MODE and VOLUME and an 8-character 14-segment display unless otherwise noted:

• An x2 head is an x5 head with fewer buttons above or to the right of the display.
• An x5 head has only 3 buttons to the right of the display.
• An x7 head has 12 buttons to the right of the display and can do DTMF.
• An x9 head (System 9000) has 12 buttons, an 11-character display, and can do DTMF.

An E7 radio was capable of 10 conventional modes and 15 systems of 16 sub-fleets each. After deleting all but the last trunking system and its modes, I was able to increase the number of conventional modes to 128, but I didn't try filling them all.

There's only so much codeplug space in the radio; each trunking system reserves space for all of its sub-fleets, whether they're utilized or not. You can increase the conventional mode space by giving up some trunking mode space, on those radios that support both.

Spectra and Astro Spectra compatible microphones:
The A9 / W9 / Series 9000 head, has its microphone jack on the rear of the control head. It's still a six-pin connector, but it is oriented vertically rather than horizontally. All of the Spectra microphones plug into either front or rear connectors. All of the mobile microphones are hand-size; there are no palm-size microphones (such as the HMN1056D that's common with MaxTracs; see the comparison photo in the Motorola section of this web site).

The microphone connector on the a Spectra microphone has 6 pins and looks like:

The pattern of the 6 pins is the same as in a DB50 plug.

...but the mic connector on the front of the radio has 10 pins...
The outer 4 are used for, among other things, the encryption keyloader.

A list of known Spectra-compatible mikes is shown below. If anybody knows of others or wants to contribute schematic scans, let Repeater-Builder know.

• Standard microphone HMN1080A (replaces HMN1052A now NLA)
• Standard microphone HMN1061A used on Systems 9000 / A9 head
• DTMF microphone HMN1032B
• DTMF microphone HMN1053A (supposedly this one won't work on an Astro Digital Spectra, I don't know why, or if this statement is even correct)
• Noise Cancelling microphone 5084898K10 (also available as HMN4030A)
• Handset (with hangup box) HMN1079B
• Water resistant microphone HMN1079A
• Motorcycle Weatherproof Microphone HMN1062A (usually paired with the HSN6003 weatherproof speaker)
• Desk-top microphone HMN1050A, B, C or D (this microphone has both the PL defeat and PTT buttons)

Spectra Mobile Power Consumption:

Model Series Standby Receive Transmit D43 (High Band 25-50w) 0.45A 2.5A 13.0A T83 (High Band 110w) 0.45A 2.5A 27A D14 (UHF 4w) 0.5A 2.5A 3.5A D34 (UHF 25w) 0.5A 2.5A 6.5A D44 (UHF 40w) 0.5A 2.5A 12.5A T84 (UHF 100w) 0.5A 2.5A 31A D45 (800 MHz 35w) 0.5A 2.5A 13.5A D17 (900 MHz 4w) 0.5A 2.5A 4.5A D27 (900 MHz 12w) 0.5A 2.5A 7.0A D37 (900 MHz 30w) 0.5A 2.5A 13.5A

NOTES: "Standby" implies receiver squelched. "Receive" is the power consumption at maximum volume setting and with white noise. All of these are MAXIMUM current values taken from Motorola manuals; most radios draw considerably less.
With the System 9000 control head, all the current drains increase by 0.2A due to the additional segments on the display and additional computer components.

Other Notes:

Programming

If RSS or the RIB is a new topic to you I suggest that you see the RSS and RIB pages at this web site.

Programming 2m and 440 MHz amateur frequencies is no problem as VHF range 1 covers 2m and UHF range 2 covers 440 MHz. However to program 900 MHz amateur frequencies into the radio you will have to hex-edit one file in the RSS package: "spectra1.exe". Instructions are available in an article below. Also the VCO might need to be modified slightly (definitely necessary for 900 MHz radios - see article below).

If you plug a programming cable into a Spectra, and the RIB is attached but not powered up, the radio can do all sorts of strange things like turn on and off and display some error codes. You'll think you have some bad connections. The RIB loads down the BUSY and BUS lines and confuses the radio. The solution is to apply power to the RIB before attaching it to the radio. The Spectra has a switched +12vDC pin in the accessory / programming connector that (among other things) was intended for powering the real Motorola RIB (RLN4008 series) through the programming cable (to pin 12 of the DB25F connector on the RIB).

Mounting Bracket
The Moto part number HLN5015 is the dash-mount mobile mounting kit, containing the bracket, some loose hardware, the power cable, with fuse holder and speaker connection. Part number 0780086N01 is the bracket only (and the same bracket is used for the control head in a remote-mount radio).

Display Font
If you look at the A9 - DEK control head photo at the top of this web page, you may notice that there is no decimal point character in the control head "font"... just uppercase alphabetics, numerics, a space and these characters: < > ? / \ @ * ( ) - and the + sign. You would really expect the decimal point / period character to be there, since you would expect to be able to display frequencies (like "146.46" or "449.000") but it's not. Bob WA1MIK took the time and programmed every keyboard character into the RSS and loaded the strings into an A7 radio; there's no way to display a decimal point on any Spectra head. If you program the keyboard decimal point into the RSS it displays as a backslash. The nearest you can get to a decimal point is the "-" (hyphen) or "=" (equals character), the latter shows up as an underscore. Or do without and live with "14646", "146-46" and "449000". Or use names for the channels like it was intended: "Simplex1" and "Sunset3". Interesting enough the "[" character (the left square bracket) can be used as a display segment test as it is translated into an "all segments on" character.

The reason you can't get some characters is that each position of the display is formed with 14 segments: one horizontally at the top and bottom, two horizontally in the middle, one each vertically at the upper left, upper center, upper right, lower left, lower center, and lower right, and four that go diagonally in an "X" pattern. There's just nothing there for a decimal point or lower-case letters. Here's part of a page from a Kenwood TK-981 manual that shows the possible display characters. It's similar if not identical to the Spectra:

Splits / Ranges
Spectra's come in many frequency bandsplits, called Ranges. Below is a list of the available ranges for VHF and UHF.

• VHF Range 1: 136-162 MHz
• VHF Range 2: 146-174 MHz
  
  
• UHF Range 1: 403-433 MHz
• UHF Range 2: 438-470 MHz
• UHF Range 3: 450-482 MHz
• UHF Range 4: 482-512 MHz

In order to determine the range of any particular radio you will have to do one of two things:
1) Read the radio with RSS (which may not work, see below)
2) Open it up and look at the part numbers on the RF modules.

Using a frequency counter to tell where it's transmitting will do no good. For example, if it was transmitting on 157 MHz (actually anywhere from 146 to 162 MHz) you could not know which of the two VHF ranges it was in without opening up the radio and looking at the part numbers on the modules. And it could have had a wrong range code plug stuffed into it or been programmed with a modified RSS... several eBay sellers have been discovered selling 403-433 MHz range radios with a 460 MHz range code plug programmed into it, and 136-162 MHz radios with a 146-174 MHz code plug.
In short, the only way to really tell is to look inside and read the module numbers.

There never was a low band Spectra. The nearest to it is the trunk-mount low band Syntor X-9000 and I have it on good authority that only 1,500 of those were ever made. They are in demand by emergency responders as they will do 25-54 MHz in one range, and when coupled to an autotuning screwdriver antenna can do drastic changes in frequency (like switching from a 33 MHZ Air Force SAR channel to the Red Cross 47.42 MHz nationwide frequency to a 39/43 MHz California Highway Patrol repeater pair), and doing it all while in motion on the highway.

Very few high power remote mount / trunk mount Spectras were made in UHF Range 2 - that particular factory configuration is a good example of pure unobtanium... Several have been field assembled (and sold to unsuspecting hams) by taking a front end and exciter from a dead Range 2 front mount radio and installing it into a Range 3 trunk mount radio, and then telling the radio it's a Range 2 but the transmitter performance may drop off drastically as you head towards 440-445 MHz (there are some modifications that can be made to the transmitter but they are not simple).

All the high power radios are remote mount / trunk mount only.

Converting a Dash Mount to a Remote Mount
To convert a dash mount radio to a remote / trunk mount you will need a HH1446A, HH1447A or HLN6008A Remote Mount Field Retrofit Kit which contains all the parts necessary. I have no idea what the differences are between the three kits.

A detailed service manual covering most models of the conventional and trunked Spectras is Motorola part number 6880102W61 at about $45. Naturally, it's No Longer Available (NLA) from Motorola.

Spectra articles and files here at repeater-builder:
(If you don't see what you are looking for, don't forget to check Mike Blenderman's site). Or if you have some information to share, repeater-builder is always looking for article donations.

Spectra Sales Brochure An original Motorola catalog sheet with abbreviated specifications. 674kb PDF.

Spectra Motorcycle Spec Sheet An original Motorola spec sheet with photos and abbreviated specifications. 189kb PDF.

Spectra Conventional Radio System Operators Manual   Motorola manual part number 6881071C55. 4mb PDF.

Spectra Parts Catalog 1mb PDF, and another version Spectra Parts Catalog. 240kb PDF.

Info on the new Moto railroad locomotive cab radio based on the Astro Spectra. 140kb PDF.< /p>

DEK schematic. 614kb PDF.

One approach to adding a COR Signal to the Spectra DB-15 Accessory Connector By Nick Markovich N2XFX

Spectra Control Head Ignition Jumper Information by Robert W. Meister WA1MIK

Why a 900 MHz Spectra Won't Receive at 902 MHz and What You Can't Do About It by Robert W. Meister WA1MIK

Interfacing External Equipment to the Spectra Mobile Radio by Robert W. Meister WA1MIK

Recapping the Spectra Mobile (a.k.a. the Time-Bomb Capacitors) by Robert W. Meister WA1MIK

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

Adding a Preamp to a UHF Spectra Radio by Robert W. Meister WA1MIK

Miscellaneous Spectra Topics by Robert W. Meister WA1MIK

The Spectra Desktop Station by (who else) Robert W. Meister WA1MIK

Spectra Dash-mount Control Head Interconnect Boards by (yet again) Robert W. Meister WA1MIK

Intro to Spectra Radio Configurations by (yup, you guessed it) Robert W. Meister WA1MIK

Setting up and using Multiple Coded Squelch (MPL) by (tired of being a lonely author) Robert W. Meister WA1MIK

Spectra Error Codes by (finally running out of things to write about) Robert W. Meister WA1MIK

Spectra Hacks (Bitbanging) by James S. Vooght K2JSV

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The photos of the A5, A7, two 900 MHz PA decks and the speaker-box-under-a-mobile photos are by Robert W. Meister WA1MIK and copyrighted by him.
The A9 / DEK head photo is by Scott Lichtsinn KBØNLY and copyrighted by him.
The Desktrac station photo supplied by A. Nony Mous.
The photo of K6CCC's truck radios by Jim Walls K6CCC and used with permission.
Artistic layout and hand-coded HTML © Copyright 2005 and date of last update by Mike Morris WA6ILQ

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