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Motorola ®
www.micor.info

"The Motorola MICOR Conversion Site"
Much of the information presented on this site was compiled by
Kevin Custer W3KKC and is Copyright © 1995 - present, all rights reserved



If you are at all serious about the MICOR radios you will want
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Note that in Motorola's product line terminology you have either a "mobile" or a "station",
and the latter term is used for both base stations and repeaters.

How to identify your MICOR
Mobiles are on the top, scroll down for stations

Note that DVP (secure) stations frequently substituted an "X" for
the center letter in the suffix (i.e. a C74RCB became a C74RXB).

Here's a simpler MICOR Mobile only identification table


Jump to:       Generic MICOR (both Mobile and Station)   Read this section first

Generic Station Information      Low-Band Station      Mid-Band Station      High-Band Station      UHF Station

Generic Mobile Information      Low-Band Mobile      High-Band Mobile      UHF Mobile

Channel Element Info       220 MHz. Conversion       Packet       Other Information      Images

Custom Built Repeaters


Information Relevant to Both MICOR Mobile and Station:

The MICOR Squelch     Explanation of the MICOR® Bi-Level Squelch.     By Kevin Custer W3KKC
MICOR® based squelch circuit   A SEITS article
Explanation of Reverse Burst and "AND" Squelch     By Kevin Custer W3KKC
Pre-emphasis, de-emphasis, clipping, and audio quality in the MICOR   By Paul Sexauer K3VIX
MICOR Muteboard®, muting audio filter amplifier     By Kevin Custer W3KKC
Modification of the MICOR PL Encoder   In some situations you want to disable the reverse-burst capability   By Kevin Custer W3KKC
COS Logic Level Inverter  A simple circuit to make positive logic COS from the audio-squelch board for those controllers that require it   By Kevin Custer W3KKC
MICOR® discriminator buffer amplifier     Great for NHRC, MCC, and other newer style controllers that mute and have de-emphasis built in
MICOR® PL® Filter   By Kevin Custer W3KKC
MICOR® PL® Filter Modification   By Kevin Custer W3KKC
An "S-Meter" for the MICOR Receiver   While this circuit was originally developed to allow a repeater receiver to drive an analog input of an ACC repeater controller there is no reason that it couldn't drive a different brand of repeater controller or even a meter...
TLN4310B and TLN4622B Audio Squelch board - full info (3 pages), 265 kB PDF   scan courtesy Eric Lemmon WB6FLY
TLN4310B-2 schematic only (horizontal, for viewing on your screen)     TLN4310B-2 schematic only (vertical, for printing)
You will probably want to print the schematic on legal paper, as it is an extended length diagram. If you are going to do any bench work, I'd suggest printing it on 11x17 paper.
Information on MICOR Channel Elements   By M. Scott Zimmerman
Modification of the MICOR "Sensitron" 450-470 MHz Receiver RF and IF Board for use in the UHF ham band   By Kevin Custer W3KKC
A step-by-step procedure on how to modify a TRE1203A (or B) or TLE8032A (or B) 450-470 MHz reciever board to operate properly below about 445 MHz.
Motorola made some special order stations in the 440-450 MHz range - either for well-funded amateur groups, or for the European market (the UHF commercial band in most of Europe starts at 440 MHz instead of 450 MHz).   Here's the factory documentation on such a radio.   65 kB PDF donated by Tim Sawyer WD6AWP
The three-page writeup is an addendum to the standard manual and covers modifications to the TRE1241A receiver and the TLE1853A exciter, plus a few other notes.


Non-Band-Specific Station Information:
Comprehensive conversion of the MICOR® Compa-Station base/repeater station   By Kevin Custer W3KKC
Synthesize your MICOR Station   By Greg Carttar (ex-WAØLCZ) of 3rd St. R & D Production Services
Previously an off-site article, now it's here on Repeater-Builder.
Modification of the MICOR PL Encoder     By Kevin Custer W3KKC
In some situations you want to disable the reverse-burst functionality. This writeup tells you how.
Notes on connecting a generic repeater controller to a MICOR station  By M. Scott Zimmerman N3XCC
Adding an ID-8 to a Micor or MSR2000 Shelf    By Jerry Matthews WAØUZI
Useful to the commercial repeaters as the amateur radio repeater controllers have built-in IDers. While an IDer is not required for GMRS, having one is a real good idea and this article is relevant there as well.
Another connection of a repeater controller (an S-COM) to the MICOR Unified Chassis Station   However this technique will work with any controller that can accept active low COR and PL decode signals and output an active low PTT signal (i.e. one that goes to ground).   By Joel Huntley WA1ZYX     (off-site link)
Modification of the older Station Control Module TLN4635B   By Kevin Custer W3KKC
These mods are relevant when using a repeater controller.
Parts layout of the TLN4635 Station Control Module: original (180 KB)   enhanced (616 KB)   enhanced and rotated (616 KB)     Provided by Eric Lemmon WB6FLY
The "enhanced" file has a bit of contrast tweaking by WA6ILQ.   The rotated file is properly aligned for printing.
Modification of the newer Station Control Module TLN5970A (or later)   By Kevin Custer W3KKC
When using a repeater controller.
Modifying the TRN4662 Squelch Gate Module as an interface to an external controller   By Richard Reese WA8DBW     (off-site link)
Modifying the TRN4662 Squelch Gate Module for better operation with a repeater controller   By M. Scott Zimmerman N3XCC
Conversion of the TRN6006 series Station Audio and Squelch board   For better audio muting   By Kevin Custer W3KKC
Modifying a TLN4310 mobile audio and squelch board for use in a base/repeater station   By Kevin Custer W3KKC
The TRN6006 is used in a station, the TLN4310 boards are use in a mobile. There are a lot more TLN4310 boards out there than TRN6006 boards. This tells you how to modify a mobile board to work in a station.
Conversion of the Compa-Station Receiver Interconnect Board   By Kevin Custer W3KKC
Documentation on the TLN5167A Intercom, TLN5900 and TLN5993 Station Metering Kit, and TLN1859 and TLN1887 Metering and Intercom Kits   Manual # 6881033E28-F 1.6 MB PDF donated by Eric Lemmon WB6FLY
The MICOR station had an optional PROM based Identifier card. The MSR2000 page has the documentation on two different but very similar cards (the major difference is the card edge connector).
Converting the Unified Chassis Station to 12vDC only   229 kB PDF by Lee Woldanski VE7FET
The standard MICOR station power supplies deliver three separate outputs: unregulated +V to the transmitter PA deck, and both regulated +12vDC and +9.6vDC to the unified chassis (the control shelf, exciter and the receiver). In some cases you want to power the station from an existing +12vDC source. This writeup shows how to modify the unified chassis to generate its own 9.6vDC. Non-unified stations can do this mod separately to the control shelf, the exciter chassis and to the receiver chassis.
Adding a PL encoder to a Micor station - Courtesy of Bob Laag WA6ISG we know that Moto had a kit for field upgrading a carrier squelch Micor station to PL Encode. In addition to the actual encoder board and the reed the TRN6188A KIT consists of:
  • 4-40 NUT - 2-7019
  • TAPPING SCREW - 3139495
  • BRACKET - 0782618K01
  • INSULATOR - 1483809K01
  • PAD - 7582902K01
The bracket fits behind the exciter board and keeps it from falling out, especially when you are removing and replacing reeds. This kit is mentioned in the back of some versions of the low band station manual and should be applicable to all bands. I do not know if any of the parts are still available.


Station Power Supplies:
Full manual for the TPN1095A, TPN1096A, and TPN1102A station power supplies   5.8 MB PDF file
This was a high-resolution scan provided by Don Kovalchik, W8DPK; it was subsequently reduced in size.
Schematic of the TPN1105 and TPN1106 station power supply   128 kB PDF
The TPN1105A can be wired for either 120v or 240vAC, but the TPN1106A is 120vAC only.   The manual for either one is 6881104E92.   This supply has the automatic power fail changeover to battery feature, plus a tone generator that puts a periodic beep on the transmitter, control line, or both.
Schematic of the TPN1110 station ferro-resonant power supply   144 kB PDF
This schematic is from manual 6881020E44-N and covers both the TPN1110A and TPN1110B models that provide unregulated 13.8v at 25 amps for the PA deck plus 12v and 9.6 volts regulated.
Schematic of the TPN1151 and TPN1152 station power supplies   73 kB PDF
The TPN1151A can be wired for 120 or 240vAC, but the TPN1152A is 120vAC only. This is a fully linear supply with separate linear regulators for the +9.6v, low and high current 12v voltages.


Low Band MICOR Station:
The low-band MICOR's came in 4 ranges, commonly called "splits": 25-30 (very, very rare), 30-36, 36-42, and 42-50 MHz. The four articles below are all oriented to the 42-50 MHz radios. If anyone would like to do a 30-36 to 10 meters conversion article please let us know.
The low band receiver is a TLB6851A (25-30 MHz), TLB6852A (30-36 MHz), TLB6853A (36-42 MHz), or TLB6854A (42-50 MHz). Later versions would have had a different trailing letter.
Motorola offered a noise blanker option (marketing called it an "extender"), usually only used in mobile radios. That receiver was the TLB6861A, TLB6862A, TLB6863A and TLB6864A series (the last digit indicated the split, just like the TLB685x series).
The TLB685x and TLB686x receivers all have a 5.26 MHz intermediate frequency. The TLB696x receivers have a 5.36 MHz IF, usually used only in a second receiver situation or on special order.
The 25-30 receiver used a x2 multiplier and high side injection, the 30-36 and 36-42 receivers used x3 and high side injection, and the 42-50 receiver used x3 and low side injection. All of the low band receivers used the K1003 channel element, none have AFC (Automatic Frequency Control) and the element doesn't have an AFC input pin.
The low band and mid band stations use a TRN6007A audio-squelch board and it is different from the TRN6006A board used in the high band and UHF stations. The difference is one capacitor (C210) and it is easily changed in the field.
Conversion of the MICOR Low-band receiver to the 6 meter amateur band   By Kevin Custer W3KKC
Conversion of the MICOR Low-band exciter to the 6 meter ham band   By Kevin Custer W3KKC
Another conversion site for MICOR Low-band to 6M Ham Band   Offsite link to KB6MIP's site
Yet another conversion article for the MICOR Low-band receiver to the 6M Ham Band   With photos, circles and arrows, and paragraphs on the back... by Robert W. Meister WA1MIK
Combining Two Micor Receivers for Better IF Performance   by John Haserick W1GPO and Robert W. Meister WA1MIK
Use a second receiver's IF section for additional filtering and better selectivity.
We don't have the low band DVP Station Manual but we do have the high band one. Until we are given one I suggest you start there if you are looking for DVP station info.
Would anyone like to do a 30-36 MHz to 10m conversion article?
TLB6310A or TLD6340A Crystal Filter and TLN5120 Installation Kit documentation   327 kB PDF
This writeup describes a very sharp notch filter that has to be custom ordered for the exact frequency of interest.   It does have between 4 and 6 db of insertion loss so it can't be used on marginal situations.   The PDF file contains both the 6881104A86 (the filters) and 6881104E36 (the installation kit) documents.   If you stumble across a filter like this in surplus at a good price, and you ever think that such a filter might be useful someday then it's worth picking it up.   You can send it back to International Crystal and they can cut a new insert for you.


Mid Band MICOR Station:
The mid band receiver is a TLC6112A or B, and is identical to the low band receiver except for frequency range and multiplier (times 6, high side injection). These were commonly used as link receivers in paging systems. The crystal filters are also optimized for the digital modulation data used for paging. These can be converted to low band receivers if you replace some coils and capacitors.
At this time we have no other information on the mid band MICOR station or mobile.


High Band MICOR Station:       (220 MHz mods are in the 220 section below)
The high band station power amplifier requires about 200mW for full output.   Other web sites and books say that it takes about twice that.   Here's why:   The high band station exciter is specified for 400 mW of power output, however, in a stock station there is always a band-pass filter between the exciter output and the amplifier input. These filters have about 2 to 3 dB loss, so the actual drive reaching the amplifier is about 200 mW.

Comprehensive conversion of the MICOR® Compa-Station base/repeater station   By Kevin Custer W3KKC
Comprehensive Description of the MICOR "Sensitron" Hi-band Receiver   By Kevin Custer W3KKC
Conversion of the MICOR "Sensitron" High-band Receiver to the 2M Ham Band   By Kevin Custer W3KKC
Now available: 132-150.8 MHz helical resonator coils   Get a real 2 meter front-end for your MICOR receiver!   By Kevin Custer W3KKC
Modification of the MICOR Exciter     By Kevin Custer W3KKC
VHF MICOR PM to FM Exciter Modification   Convert your PM exciter to True FM!  By Kevin Custer W3KKC
VHF MICOR tuning instructions   By Kevin Custer W3KKC
Retuning the VHF MICOR Bandpass Filter   By Kevin Custer W3KKC
A Conversion of a high band MICOR Intermittent Station to a Repeater   4.2 MB PDF By Lawrence Glaister VE7IT
Converting a high band PURC Station to a Repeater   By Matt Krick K3MK
Documentation on the high band MICOR Preamp model TLD8421A, TLD8421B, TLD8422A or TLD8422B   917 kB PDF Donated by Eric Lemmon WB6FLY
Photos by Tony Faiola K3WX:       photo 1       photo 2       photo 3       photo 4 (shows mounting bracket used to mount the preamp on the back of a Spectra-Tac or Aux Receiver chassis)
(the 15D number visible in the first photo is the casting number, not the preamp part number)
Note that if you need a preamp and can't find one that AngleLinear sells a very nice drop-in preamp, and a mobile mounting bracket is available.
Conversion of the TLD8422 high-band factory preamp to the 2M ham band   By Kevin Custer W3KKC
MICOR High Band Service Sheet Pg 1   This is page 1 of Moto manual 6881101E02-M.   2.2 MB PDF Donated by Eric Lemmon WB6FLY
MICOR High Band Service Sheet Pg 2   This is page 2 of the above. 844 kB PDF
MICOR DVP VHF Station Manual 6881036E40-B NLA
This manual includes the TLN5979A backplane. Complete manual (17.6 MB)
In sections: Pages 1-122 (7.8 MB)   Pages 123-165 (5.3 MB)   Pages 166-187 (4.9 MB)
Here's how to get the 5979A backplane working without the DVP modules, courtesy of Eric WB6FLY:
  1. Remove all jumpers EXCEPT 2, 4, 5, and 7. JU4 is a diode, with the cathode bar on top.
  2. On Slot 10 for the Code Detect module, jumper pin 7 to pin 15, and jumper pin 10 to pin 17.
  3. Use ONLY the 5970 SCM.
  4. Remove all modules except the SCM, Squelch Gate, and Timeout Timer.
Make certain the station works properly before connecting an outboard controller.
TLB6310A or TLD6340A Crystal Filter and TLN5120 Installation Kit documentation   327 kB PDF
250/375 Watt 136-174 MHz Upright Base and Repeater (RT) Station Documentation for the B83RCB and B93RCB stations.


UHF MICOR Station:
Comprehensive conversion of the MICOR® Compa-Station base/repeater station   By Kevin Custer W3KKC
Motorola made some special order stations in the 440-450 MHz range   Here's the factory documentation on such a radio.   65 kB PDF donated by Tim Sawyer WD6AWP
Modification of the MICOR "Sensitron" 450-470 MHz Receiver RF and IF Board for use in the UHF ham band   By Kevin Custer W3KKC
A step-by-step procedure on how to modify a TRE1203A (or B) or TLE8032A (or B) 450-470 MHz reciever board to operate properly below about 445 MHz.
Repair notes and schematic for the UHF Station Tripler   By Bill Hance KD7CWA
Conversion of the UHF "Sensitron" Receiver to 440 MHz Ham Band   By Kevin Custer W3KKC
Additional Info and Images about the above conversion for 435-450 MHz   By Robert Meister WA1MIK
Documentation on the UHF preamp model TLE8191A (or B) and TLE8192A (or B)   531 kB PDF 6 page file from Eric Lemmon WB6FLY
Note that if you need a preamp and can't find one that AngleLinear sells a very nice drop-in preamp that has much better performance.
MICOR UHF base station PA manual section and schematic   530 kB PDF file courtesy of Robert Meister WA1MIK
Modification of the Micor Exciter     By Kevin Custer W3KKC
Tuning the UHF Station BPF's and Circulator (antenna network)  By Kevin Custer W3KKC


Information relevant to MICOR Mobiles being converted to Repeater or Link duty:
Notes:
1) The MICOR mobile chassis has a heat sink rated at only 35 watts - yes, that fact is in the MICOR mobile manual. Therefore radios higher than 45 watts are best left in mobile service.
2) The VHF MICOR transmitter power amplifier stages use PNP transistors where the UHF radio uses NPN in the same area. Be careful when you do a rebuild that you have the right parts !!!
3) The normal mounting of a MICOR mobile has the radio mounted essentially upside down (the circuit boards are mounted in the top of the case facing downward). As such the control connector pinout is not what you would expect. Here is a drawing of the pinout viewed from outside the radio, looking at the front.

Generic Mobile Information:
Front casting modification for a second antenna connector   By Kevin Custer W3KKC
Until you have used a full duplex mobile on UHF you really don't know what you are missing. A second antenna jack makes it easy.
Duplex modification of MICOR mobile audio and squelch board   By Kevin Custer W3KKC
MICOR Muteboard®, muting audio filter amplifier   By Kevin Custer W3KKC
Modification of the MICOR PL Encoder   In some situations you want to disable the reverse-burst functionality.   By Kevin Custer W3KKC
COS Logic Level Inverter   For making positive logic cos from the Audio-Squelch board.   By Kevin Custer W3KKC
The replacement microphone coiled cord for the Micor, Syntor, Mitrek and several others (not the Spectra) is part number 083731M01


Low-band MICOR Mobile: The low-band MICOR's came in 4 ranges: 25-30, 30-36, 36-42, and 42-50 MHz.
The low band receiver part numbers are: TLB5851A and TLB5851B is for 25-30 MHz (very, very rare), TLB5852A and TLB5852B is 30-36 MHz, TLB5853A and TLB5853B was 36-42 MHz, and TLB5854A and TLB5854B is 42-50 MHz. On all of them the IF is 5.26 MHz, or 5.36 MHz on special order.
The 25-30 receiver used a x2 multiplier and high side injection, the 30-36 and 36-42 receivers used x3 and high side injection, and the 42-50 receiver used x3 and low side injection.
Conversion of the MICOR Low-band receiver to the 6 meter ham band   By Kevin Custer W3KKC
Conversion of the MICOR Low-band exciter to the 6 meter ham band   By Kevin Custer W3KKC
Another conversion site for MICOR Low-band to 6M Ham Band     Offsite link to KB6MIP's site
Yet another conversion article for the MICOR Low-band receiver to the 6M Ham Band   With photos, circles and arrows, and paragraphs on the back... by Robert W. Meister WA1MIK
Would anyone like to do a 30-36 MHz to 10m conversion article?


High-band MICOR Mobile:       (220 MHz mods are in the 220 section below)
See the station section for a breakdown on Micor VHF (high band) receivers.
Duplex conversion of a standard VHF mobile to repeater   By Kevin Custer W3KKC
Duplex conversion of Railroad VHF mobile to repeater   By Kevin Custer W3KKC
Duplex conversion of a VHF mobile to a repeater station By Jim Reese WD5IYT
Duplex Conversion of the mobile antenna switch   By Kevin Custer W3KKC
VHF Exciter Models   An explanation of the 3 different exciters common to the VHF radio.   By Kevin Custer W3KKC
VHF PM to FM Exciter Modification   Convert your PM exciter to True FM!   By Kevin Custer W3KKC 
VHF board model number frequency ranges An explanation of the board numbers on a VHF MICOR.   By Kevin Custer W3KKC
132-150.8 MHz helical resonator coils for the MICOR  Get the right coils for your 2 meter front-end.   By Kevin Custer W3KKC
Comprehensive Description of the "Sensitron" Hi-band Receiver   By Kevin Custer W3KKC
Conversion of the "Sensitron" High-band Receiver to Ham Band  By Kevin Custer W3KKC
Modification of the VHF Exciter   By Kevin Custer W3KKC
Retuning the VHF Bandpass Filter   By Kevin Custer W3KKC
VHF tuning instructions   By Kevin Custer W3KKC
Documentation on the high band preamp model TLD8421B and TLD8422B   917 kB PDF Donated by Eric Lemmon WB6FLY
Photos by Tony Faiola K3WX:       photo 1       photo 2       photo 3       photo 4 (shows mounting bracket used to mount the preamp on the back of a Spectra-Tac or Aux Receiver chassis)
(the 15D number visible in the first photo is the casting number, not the preamp part number)
Note that if you need a preamp and can't find one that AngleLinear sells a very nice drop-in preamp, and a mobile mounting bracket is available.
Conversion of the High-band Preamp To Ham Band   By Kevin Custer W3KKC
Documentation on the 45 watt VHF PA deck   3 MB PDF 15 page file from Eric Lemmon WB6FLY
High Band Service Sheet Pg 1   This is Moto manual 6881101E02-M Page 1. 2.2 MB PDF Donated by Eric Lemmon WB6FLY
High Band Service Sheet Pg 2   This is page 2 of the above. 944 kB PDF


UHF MICOR Mobile:
The UHF receiver is a TRE120nA or B (where "n" is 1 to 5), and the IF is 11.7 MHz, or 11.8 MHz if needed to avoid mixes.
The TRE1201A or B is for 406-420 MHz, the TRE1202A or B is 420-450 MHz, the TRE1203A or B is 450-470 MHz, the TRE1204A or B is 470-494 MHz and the TRE1205A or B is 494-512 MHz.
All UHF receivers used a x24 multiplier. The high versus low injection decision was dependent on several parameters, read the first article below for the details.
A Technical Explanation of the MICOR UHF Mobile Radio Set   A walkthrough of how only one channel element / crystal can work for receive,  transmit repeat and transmit simplex.   By Kevin Custer W3KKC
Motorola's own technical description of the UHF MICOR Mobile Radio   Section 4, all 33 pages of it, from the official manual.   2.5 MB PDF By Kevin Custer W3KKC
Duplex conversion of MICOR® UHF mobile to repeater station   By Jim Reese WD5IYT
Information on the UHF Mobile Low Level Amplifier (LLA)   How to increase the life expectancy     By Jeff DePolo WN3A
Conversion of the MICOR "Sensitron" UHF Receiver to the UHF ham band   By Kevin Custer W3KKC
Modification of the MICOR UHF Exciter     By Kevin Custer W3KKC
Documentation on the UHF preamp model TLE8191A and TLE8192A   531 kB PDF 6 page file from Eric Lemmon WB6FLY
Note that if you need a preamp and can't find one that AngleLinear sells a very nice drop-in preamp, and a mobile mounting bracket is available.
Emergency Medical Systems Duplex / Repeater UHF Mobile Radio manual supplement   15.8 MB PDF file courtesy of K9ROD


Custom Modifications, Conversions and Parts Suppliers for MICOR® Mobiles and Stations:
MICOR Repeater Conversions from Repeater-Builder
Custom Conversions by Scott Zimmerman - from Repeater Builder (the company)


Channel Element Info
MICOR channel element schematic diagrams and other information   (with photos)   by Scott Zimmerman - N3XCC
What's inside the K1003 channel element   (with photos and schematic)   by Robert W. Meister - WA1MIK


220 MHz. Modifications for the MICOR High-Band Radio
Comprehensive Conversion of the TLD8262A or TLD8262B MICOR High-Band Exciter to 222 MHz   By Kevin Custer and Scott Zimmerman (new method)
Comprehensive Conversion of the MICOR High-Band Receiver to 222 MHz   By Kevin Custer W3KKC (new method)
This writeup covers the following receiver boards (where "x" is 1, 2, 3 or 4 and "y" is A or B): TLD407xy, TLD527xy, or TLD827xy.
Conversion of the MICOR VHF exciter Band-Pass Filter to 220 MHz   By Lee Woldanski VE7FET
This is the conversion process for the station filter.
Exciter 220 MHz Band-Pass Filter Conversion   by David A. Cooley N5XMT
This is the conversion process for the mobile filter.
An add on 222 MHz. amplifier   by David A. Cooley N5XMT
220 MHz Low Pass Filter   by David A. Cooley N5XMT
MICOR 222 MHz. Modifications   Considerations from SEITS
Conversion of the TLD5803 MICOR VHF exciter to 220 MHz   By John Slusser WD7F, Craig Walker KD7TXO and David Stanford K7IOU   (offsite link)
Conversion of the MICOR VHF Exciter Helical Band Pass Filter to 220 MHz   By John Slusser WD7F, Craig Walker KD7TXO and David Stanford K7IOU   (offsite link)
Conversion of the MICOR VHF PA to 220 MHz   By John Slusser WD7F, Craig Walker KD7TXO and David Stanford K7IOU   (offsite link)
Conversion of the TFD5102A Harmonic Filter Cutoff Point From 190 MHz to 230 MHz   By John Slusser WD7F, Craig Walker KD7TXO and David Stanford K7IOU   (offsite link)
These articles are outdated and are here only for reference.
MICOR Hi-Band Exciter to 222 MHz. Modification (old SEITS method) Original Concept by David A. Cooley N5XMT
MICOR Hi-Band Receiver to 222 MHz. Modification (old SEITS method) Original Concept by David A. Cooley N5XMT


Packet Modifications for the MICOR:
9600 baud modifications for the UHF MICOR   By Verne Buland


Other information relating to the Motorola MICOR:
Other Motorola information at WA8DBW's web site     By Richard Reese  WA8DBW offsite link
A collection of Miscellaneous MICOR information (that used to be on this page)     By Mike Morris WA6ILQ


Systems 90 Information:
Manuals in this section courtesy of Paul Fraas KD0CST, and were scanned and PDF'd by Eric Lemmon WB6FLY

Quick Call - Mobile Selective Signaling Decoder - TLN1389A   1.3 MB
Mobile Public Address - TLN1392A  555 kB
Mobile Multiple PL Encoder - TLN1395A, and TLN1396A   1.5 MB
TLN1395A (VHF) and TLN1547A (UHF): four tone frequencies,
TLN1396A (VHF) and TLN1548A (UHF): eight tone frequencies
Quik Call II Mobile Paging Decoder - TLN1390A, and TLN1391A   1.3 MB
TLN1390A: four-reed mobile paging decoder, TLN1391A: two-reed mobile paging decoder
Single Tone Encoder - TLN1393A, and TLN1394A   596 kB
TLN1393A: one-tone output, TLN1394A: five-tone output
Voice Privacy Adapter - TLN1400A   888 kB


Scanned Images and PDF Files:         Most are oriented for printing, not viewing...
MICOR palm microphone TMN6054A documentation   130 kB PDF including schematic
This same mobile microphone was used on the Mitrek. Click here for a better scan (486 kB)
MICOR mobile radio interconnect board relay area   118 kB
MICOR Mobile Audio and Squelch Board layout   157 kB
MICOR Audio and Squelch Board schematic   166 kB
MICOR High-Band Exciter Board layout   157 kB
Picture of the MICOR mobile control head back side   38 kB (vertical for printing)       Horizontal (for viewing)   38 kB
MICOR mobile control head schematic   261 kB
MICOR Station Control Module for Securenet stations   1 MB PDF file courtesy of WA3WOM
The Base and Repeater Control and Applications Manual 6881025E60-F   12.4 MB PDF file courtesy of Eric Lemmon WB6FLY
TLN5167A Intercom, TLN5900 and TLN5993 Station Metering Kit, and TLN1859 and TLN1887 Metering and Intercom Kits Manual 6881033E28-F   1.6 MB PDF file courtesy of Eric Lemmon WB6FLY
TLN1552A Station Metering and Intercom Kit Manual 6881018E26-D   825 kB PDF file courtesy of Eric Lemmon WB6FLY
UHF Station RF Manual 6881025E50-H   11.1 MB PDF file courtesy of Eric Lemmon WB6FLY
Community Repeater Station Supplement 6881025E55-B   5.9 MB PDF file courtesy of Eric Lemmon WB6FLY
PURC Control and Applications Manual 6881060E70-B   13.5 MB PDF file courtesy of Eric Lemmon WB6FLY
MICOR Base Station Accessories (Multiple Tone PL Options) Manual 6881106E30-B   4.0 MB PDF file courtesy of Eric Lemmon WB6FLY
QLN2812A Station Identifier Field Modification Kit   1.2 MB PDF file provided by John Gilbert KA4JMC

Subject - MICOR High-Band Exciter transmit frequency spacing.
Bob Swoger, K9WVY points out that the Motorola manual is in error when it states the High Band MICOR Mobile has a transmitter spread of only 1.5 MHz.  That is what the marketing group told the sales force.   Actually, the transmitter spread is 3 MHz on the standard production radio.  The designer of the first MICOR HB exciter was Jim Cox, a non-ham and laid off shortly after the MICOR shipped in 1970 due to the fact that he was the oldest and losing his hair.   That first exciter board was single sided and had grounding problems due to not enough copper foil.   This was a problem with the early PC board layout people.   They wanted to start with a non copper clad board and add copper.   Engineers wanted them to start with a double sided copper clad board and remove copper.   Jim's board indeed was only 1.5 MHz wide. Soon after another engineer named Don Nicklos (spelling?) made a double sided board that solved a lot of problems with proper grounding.   Don told me the new board could easily do 2 MHz and more.   I checked it out and found it could do 3 MHz.   Marketing was dead set against changing the published spec.

Then the State of Wisconsin put out a request for bid for high power high band radios with a transmitter spread of 2 MHz. GE could do this with their standard MASTR II. The MICOR as advertised would require the Wide Spaced Exciter option which would cost $150 more than the GE MASTR II as I recall.   My boss at that time had heard that I was running a MICOR mobile on 2 meters without a wide spaced exciter option and called me into the office.   He asked me to prove the standard product was as wide as I claimed it was by testing the radio between –40C to +70C.   I found I could get more that 3 MHz transmitter separation if I tuned the exciter 1 MHz above the lowest frequency.

We beat GE by $5 per box and won the contract. So, please change the web page to indicate the exciter is 3 MHz wide if it is center tuned 1 MHz above the lowest frequency. -- Bob

About Bob Swoger  My name is Robert E. Swoger, K9WVY.  I was at Motorola from 1965 until I retired in 2002.   I was in the original MICOR Mobile design team from 1969 on.   Not only did I design new MICOR radios, I later designed and FIXED designs of standard and custom MICOR Mobile and Bases.   When I wrapped it up I was in the design team of Saber, Cosmos and Spectra radios.

Several of the correction and additions to this site have been made by Bob Swoger, Thanks Bob!
Kevin Custer and the Repeater Builder Group.

(M)ore (I)ntegrated (C)ircuits for (O)ptimum (R)eliability - MICOR


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