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).
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.

Micor VHF (high band) receiver model numbers
VHF Range 1 132-142 MHz	VHF Range 2 142-150.8 MHz	VHF Range 3 150.8-162 MHz	VHF Range 4 162-174 MHz	Comments / Notes
TLD4071A or B	TLD4072A or B	TLD4073A or B	TLD4074A or B	Four channel receiver - station and mobile (oldest)
TLD5271A or B	TLD5272A or B	TLD5273A or B	TLD5274A or B	Four channel receiver - station and mobile (older four channel boards)
TLD5781A or B	TLD5782A or B	TLD5783A or B	TLD5784A or B	Four channel DVP receiver (Digital Voice Privacy, a form of scrambling or encryption)
TLD8271A or B	TLD8272A or B	TLD8273A or B	TLD8274A or B	Eight channel receiver - usually found in mobiles (newest)
TLD8451A or B	TLD8452A or B	TLD8453A or B	TLD8454A or B	Extender receiver

Overall, range 3 is the most common in surplus. Most railroad radios are range 4.
The range 1 and range 2 are very, very rare, I've only seen one of the TLD4072 and it was in a factory 2m 250w base station that was originally a dispatch base for the on-base security at an Air Force base.   I've seen one 8271 and it was on a 142.7 MHz Shore Patrol channel (yup, out of band).   I've seen a few of the TLD5782 and they were in Civil Air Patrol repeaters (the input was around 143 MHz).

The 150.8-162 MHz range receiver is much more common than a genuine 142-150.8 MHz receiver.   There is no such thing as a 132-150.8 MHz receiver - it's either 132-142 MHz or 142-150 MHz - despite what you read elsewhere or on eBay (however the matching exciters were in two ranges - 132-150.8 and 150.8-174 MHz).   The helical resonators were made in two splits: 132-150.8 and 150.8-174 MHz.   The high split preselector can be converted to low split (or to 220 MHz).   You can convert it to 142-150.8 MHz for the cost of 5 coils and five capacitors.   You may or may not need one resistor.   See these two articles: MICOR high band receiver conversion and Parts to rebuild your Micor receiver.   Or you can have Kevin W3KKC do it for you.

All VHF Micor high band receivers used an IF of 11.7 MHz (or 11.8 MHz on special order) and a x9 multiplier.   The 132-142 MHz and 142-150.8 MHz receivers used high side injection, the 150.8-162 MHz and 162-174 MHz receivers used low side injection.   All use either a K1005 (0.0005%) or a K1006 (0.0002%) channel element (but the K1006 required an AFC amplifier module and those are very rare... if anyone has a schematic please let us know).   If you find a KXN1022 channel element than you have a shifted IF receiver (i.e. the IF is 11.8 MHz instead of the standard 11.7 MHz). The element is the same internally, the changed numbers clued the rock chippers to calculate for 11.8 MHz instead of 11.7 MHz.   The most common reason for a shifted 11.8 MHz IF was in a second receiver.   The other was if the customer had two channels exactly 2.925, 3.9, 5.85 or 11.7 MHz apart.
Moto offered a kit (TLE8610A) if a receiver needed to be moved (in the field) from 11.7 MHz to 11.8 MHz.

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.

	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   This writeup covers two topics.   The first is due to the fact that the standard Motorola microphone has a preamp inside the cartridge, and the radio supplies DC voltage on the mic audio lead to run it.   The circuitry involved can load down the audio output line of a repeater controller connected to the microphone input.   The second topic that is covers is a modification to ensure proper keying of the transmitter.   If the PL encoder is removed the path for keying the exciter is removed.   Motorola provided a jumper, the better way is to use a diode.   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   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   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 68P81101E02-M.   Donated by Eric Lemmon WB6FLY MICOR High Band Service Sheet Pg 2   This is page 2 of the above.
	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 This writeup describes a very 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 in marginal receive situations (or put a GOOD non-overloading preamp like an AngleLinear ahead of it). The PDF file contains both the 68P81104A86 (the filter) and 68P81104E36 (the installation kit) documents.
	250/375 Watt 136-174 MHz Upright Base and Repeater (RT) Station Documentation for the B83RCB and B93RCB stations. This came to us as several PDF files (one of which was bad) in a large ZIP file. The individual pieces can be downloaded by clicking on the appropriate section below. They've been arranged in a somewhat logical order. This does not cover the receiver or control sections; they can be found in other manuals. Specifications and Model Charts 6 MB Description 3 MB Maintenance 9 MB Exciter 10 MB Driver 7 MB Exciter/Driver Interconnect Board 3 MB Power Control Board 8 MB 250/375 watt Power Amplifiers 9 MB Station Metering 6 MB Antenna Relay 500 KB

UHF MICOR Station:

	The UHF station power amplifier deck has a BNC input and needs about 2 watts of on-channel drive to develop full ouput.   One handy method of testing the PA deck is to use a 2w UHF handheld with a female BNC antenna connection (like an Icom IC-4AT) and a short male-BNC to male-BNC cable.   Have the station powered up.   Unplug the BNC cable from the tripler and plug in the jumper to the handheld antenna jack.   Have a metered dummy load (such as a Bird Termaline) plugged into the PA deck output.   Dial up your transmit frequency on the handheld and Key it.   You should see full RF power out.
	Motorola made some special order stations in the 440-450 MHz range - either for well-funded amateur groups, or for the European market (the low end of the UHF commercial band in most of Europe is 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.
	Modification of the MICOR "Sensitron" 450-470 MHz Receiver RF & 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   530k PDF file courtesy of Robert Meister WA1MIK
	Modification of the Micor Exciter   This writeup covers two topics.   The first is due to the fact that the standard Motorola microphone has a preamp inside the cartridge, and the radio supplies DC voltage on the mic audio lead to run it.   The circuitry involved can load down the audio output line of a repeater controller connected to the microphone input.   The second topic that is covers is a modification to ensure proper keying of the transmitter.   If the PL encoder is removed the path for keying the exciter is removed.   Motorola provided a jumper, the better way is to use a diode.   By Kevin Custer W3KKC
	Tuning the UHF Station BPF's and Circulator (antenna network)  By Kevin Custer W3KKC
	We don't have the UHF 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.

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 & 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