Brinkley Electronics MOTRAC DATA

MOTRAC INFO

LOW BAND 25-54 MHZ

DIGIT

PROPERTY

VALUE

DESCRIPTION

1^ST T Trunk Mount

U Dash Mount (Universal)

2^ND RF POWER 4 40 WATTS

5 60 WATTS

7 100 WATTS

3^RD BAND 1 VHF LOW (25-54 MHZ)

4^TH H

L

5^TH H

6^TH T

7^TH SQUELCH 1 CARRIER

3 PL

8^TH/ 9^TH CH SETUP 10 1 CHANNEL

3 2 CHANNEL

9 4 CHANNEL

10^TH

VHF 136-174 MHZ

DIGIT

PROPERTY

VALUE

DESCRIPTION

1^ST T Trunk Mount

U Dash Mount (Universal)

2^ND RF POWER 4 40 WATTS

5 60 WATTS

6 90 WATTS

7 100 WATTS

3^RD BAND 1 VHF HIGH(136-174 MHZ)

4^TH M

5^TH H

6^TH T

7^TH SQUELCH 1 CARRIER

3 PL

8^TH 1

9^TH CH SETUP 0 1 CHANNEL

3 2 CHANNEL

9 4 CHANNEL

10^TH

The following is courtesy of Mike, WA6ILQ :

Generic info:

Sample: T64LHT3190-AK-SP4

First letter: T, U, or X. The only difference between T and U is two threaded holes in the
front of the "U" radio to allow a dash-mount control head to be screwed to the front of the radio.
I believe that they are 6/32 threaded. The dash-mount heads are somewhat rare as they make
decent bench-top control groups for repairs and people tend to snatch them up. They also didn't
make very many... The Motrac, Motran, and Mocom-70 head are completely interchangeable
except for the HHT Motrac series. They used 4 wires for independent switching of the RX and
TX frequencies in a 2-freq radio. The LHTs and MHTs used 4 wires for 4 frequencies.
Any special combinations were accomplished with diodes in the radios. See the section on SP for
an explanation of the X-prefix.

Sample: T64LHT3190-AK-SP4

DIGIT DESCRIPTION

1ST "T"

2nd (6 in our example) Indicates the power level of the radio. The same number can mean different things depending on the radio.

0    = no transmitter (i.e. a paging receiver, or a monitor receiver).

1-3 = is found in hand helds and special purpose mobiles (i.e. fork lifts that only need to
        talk within a plant)
3-7 = is found in mobiles (30-110w)
           LB       HB      UHF
3       30     ??          25
4       40       30          45
5     55       60          75
6       90      90          ??
7      100      110         100

The 51/61/71 and 53/63/73 LHT/MHT radios were almost identical except for power supply configuration - additional transistors in the side heat sinks for higher power and different jumpering in the high voltage section. The transistors are color coded as to beta with different paint dots. If you blow one (or decide to add additional ones) it must be replaced/matched with the same color paint dot.

8 is rare in mobiles - I've only seen one, and it was a 7 with a second TX (should have been an X or SP).

9 is 250w or 330w base stations
Note that the number has no relationship to the power in watts.
A 3 in a mobile is 30w, in a handheld is 3w.

3rd (4 in our sample). The band.

0=low frequency - perhaps a 75kilohertz carrier-current paging transmitter
1=low band - 25-50mhz
2=75mhz (special industrial)
3=136-172mhz
4=406-512
5=800mhz
6=900mhz

4th (L in our sample). The receiver type. H receivers were the first Motracs, and were made in 5 versions on highband, 4 on UHF, and had an L-C front end. H-Rxs were crystal oven, Ls and Ms were channel elements. The early H RXs had 12mhz IFs, the last version had an 8mhz IF. L recivers were 8mhz and had a much better active helical front end - they were more stable, much narrower, but wouldn't duplex worth a damn. The "M" reciver was made for the high band and UHF radios and was totally passive to the first mixer, was much, much better on adjacent channel rejection and a dream to duplex.

5th (H in our example) All the Motracs had "H" transmitters, with many differences between the LB, HB and UHFs. Again, the Txs with the H receives were crystal oven, the TXs with the Ls and Ms were channel elements. The H TXs were hybrids, with transistors in the audio circuits and all tubes elsewhere. The Ls and Ms had transistors in the low level RF stages - generally the only tubes were the driver and final. The "S" transmitter I am unfamilar with.

The only differences between the 5x, 6x and 7x in the LHTs and MHTs was the position of the power supply jumpers - for 60w, 90w or 110w on low band or high band (I believe the UHF is similar, but in 40/60/90w, but it's been years since I worked on a UHF MHT). The finals were and still are very expensive, I suggest that if you stumble across a 7x that you move the jumpers to the 6x position and quadruple your final life.

6th T - transistorized power supply. Models were made as 12v Negative ground only, 12v switchable (many big trucks are positive ground), 6v/12v negative, 6v/12v/switchable, and I've seen a few 12v/24v/switchable. Railroad radios have a wierd DC voltage (60vDC? I'm not sure) but usually have a 12v mode for bench testing.
N - no power supply. These are Motrans that use 12v only - usually the MSN series. Note that the same letter in a handheld means rechargeable battery.

B - Base stations.

7th 1 RX has no PL decoder (the com-spec TS32 can be added)
2 (rare) special decoder - maybe 2-tone paging
3 RX has PL.

8th 0 Wideband (15khz deviation) (rare)
1 Narrowband (5khz)
4 (Low band only) Narrowband with extender

Third and fourth:
00 Single frequency
10 2 freq TX, 1 freq RX
30 Two freq
60 Three freq - but not consistently.
90 Four freq
any other combination - special order for a fleet. Numbers may not be consistent. I've seen two "32"s that were 3f TX and different count on RX frequencies.

HHTs are maxed out as 2f, any LHT or MHT can be 4f TX and 2f RX by adding caps and resistors, maybe 1 coil in the RX. Adding the 3rd and 4th RX can be done but requires a special circuit board to hold the 3rd and 4th channel element.

There were a few 6 freq radios made for MTS usage, they had a special board that held the 4 extra elements (2 TX and 2 RX) that bolted in place of the TX PL encoder. I have a 64LHT 6freq.

Trailing letters: (AK In our example) Additional version information. GENERALLY, the first letter is the radio revision, a trailing "K" means that it was shipped as a "Kit" with a speaker, mike, control head, control cable, fuse block, antenna, RF noise suppression kit, mike clip/pl hang up box, and installation kit (screws, tie wraps, etc). Fleets are
ordered many times with the proper number of kits, and a few extra radios. I've seen one radio with an "ABK" nameplate.

SP<some number> A special production radio was any custom version that was made as a modification to a standard radio, but in such a quantity that it wasn't a full production run. The exact same radio produced as a seperate complete production run would have an X prefix. For example, I have an ex-LAPD Motrac with dual receivers - you can see the control head in the old Adam-12 TV series. It is a X43HHT-3100C with an extended case, with the second RX in between the main RX and the power supply. I have an almost identical radio that was made for a midwest sheriffs department but it is a U43HHT-1130E-SP<some number> nameplate.

I've also seen "X" radios that were indistinguishable from a standard radio. Such a mystery...


Inside the radio - GENERALLY, a trailing "1" on the TLD 6nnn number on the receiver front end 
casting identifies the "range" of the RX (and the TX assembly follows the convention).  Motorola
seem to use this a lot, I've found it valid on Motrac, Motran, Mocom-70s, and Micors.  It MAY 
be valid in the Syntors, Syntor-Xs, and Syntor-X9000s, I do not know.  A trailing "1" marks it 
as a 136-150mhz, a "2" means 150-160mhz, and a "3" is a 160-170mhz unit. 
Ditto on low band - 1=25-30mhz), 2=30-36, 3=36-42, 4=42-50. Some models refer to these 
ranges as "L", "M", "H" and "HH".  On UHF it's similar, 1=406-420(L), 2=420=440(?), 
3=450-470(M), 4=470-494(H), 5=494-512mhz(HH).  Note that 440-450 is commercial in
Europe, my UHF repeater has a european Micor 440 RX that came home in a friend's luggage...
Also, the Motrac UHF base manual lists a 440-450 front end as a valid part number, the mobile 
book doesn't list it at all...  Watch the low band radios, there were a bunch made for the
low-band mobile telephone channels that have the RX in one range and the TX in another.

DIGIT	PROPERTY	VALUE	DESCRIPTION
1^ST		`T`	Trunk Mount
		`U`	Dash Mount (Universal)
2^ND	RF POWER	4	`40 WATTS`
		5	`60 WATTS`
		7	`100 WATTS`
3^RD	BAND	1	VHF LOW (25-54 MHZ)
4^TH		H
		L
5^TH		H
6^TH		T
7^TH	SQUELCH	1	CARRIER
		3	PL
8^TH/ 9^TH	CH SETUP	10	1 CHANNEL
		3	2 CHANNEL
		9	4 CHANNEL
10^TH

DIGIT	DESCRIPTION
1ST	"T"
2nd	(6 in our example) Indicates the power level of the radio. The same number can mean different things depending on the radio. 0 = no transmitter (i.e. a paging receiver, or a monitor receiver). 1-3 = is found in hand helds and special purpose mobiles (i.e. fork lifts that only need to talk within a plant) 3-7 = is found in mobiles (30-110w) LB HB UHF 3 30 ?? 25 4 40 30 45 5 55 60 75 6 90 90 ?? 7 100 110 100 The 51/61/71 and 53/63/73 LHT/MHT radios were almost identical except for power supply configuration - additional transistors in the side heat sinks for higher power and different jumpering in the high voltage section. The transistors are color coded as to beta with different paint dots. If you blow one (or decide to add additional ones) it must be replaced/matched with the same color paint dot. 8 is rare in mobiles - I've only seen one, and it was a 7 with a second TX (should have been an X or SP). 9 is 250w or 330w base stations Note that the number has no relationship to the power in watts. A 3 in a mobile is 30w, in a handheld is 3w.
3rd	(4 in our sample). The band. 0=low frequency - perhaps a 75kilohertz carrier-current paging transmitter 1=low band - 25-50mhz 2=75mhz (special industrial) 3=136-172mhz 4=406-512 5=800mhz 6=900mhz
4th	(L in our sample). The receiver type. H receivers were the first Motracs, and were made in 5 versions on highband, 4 on UHF, and had an L-C front end. H-Rxs were crystal oven, Ls and Ms were channel elements. The early H RXs had 12mhz IFs, the last version had an 8mhz IF. L recivers were 8mhz and had a much better active helical front end - they were more stable, much narrower, but wouldn't duplex worth a damn. The "M" reciver was made for the high band and UHF radios and was totally passive to the first mixer, was much, much better on adjacent channel rejection and a dream to duplex.
5th	(H in our example) All the Motracs had "H" transmitters, with many differences between the LB, HB and UHFs. Again, the Txs with the H receives were crystal oven, the TXs with the Ls and Ms were channel elements. The H TXs were hybrids, with transistors in the audio circuits and all tubes elsewhere. The Ls and Ms had transistors in the low level RF stages - generally the only tubes were the driver and final. The "S" transmitter I am unfamilar with. The only differences between the 5x, 6x and 7x in the LHTs and MHTs was the position of the power supply jumpers - for 60w, 90w or 110w on low band or high band (I believe the UHF is similar, but in 40/60/90w, but it's been years since I worked on a UHF MHT). The finals were and still are very expensive, I suggest that if you stumble across a 7x that you move the jumpers to the 6x position and quadruple your final life.
6th	T - transistorized power supply. Models were made as 12v Negative ground only, 12v switchable (many big trucks are positive ground), 6v/12v negative, 6v/12v/switchable, and I've seen a few 12v/24v/switchable. Railroad radios have a wierd DC voltage (60vDC? I'm not sure) but usually have a 12v mode for bench testing. N - no power supply. These are Motrans that use 12v only - usually the MSN series. Note that the same letter in a handheld means rechargeable battery. B - Base stations.
7th	1 RX has no PL decoder (the com-spec TS32 can be added) 2 (rare) special decoder - maybe 2-tone paging 3 RX has PL.
8th	0 Wideband (15khz deviation) (rare) 1 Narrowband (5khz) 4 (Low band only) Narrowband with extender
	Third and fourth: 00 Single frequency 10 2 freq TX, 1 freq RX 30 Two freq 60 Three freq - but not consistently. 90 Four freq any other combination - special order for a fleet. Numbers may not be consistent. I've seen two "32"s that were 3f TX and different count on RX frequencies. HHTs are maxed out as 2f, any LHT or MHT can be 4f TX and 2f RX by adding caps and resistors, maybe 1 coil in the RX. Adding the 3rd and 4th RX can be done but requires a special circuit board to hold the 3rd and 4th channel element. There were a few 6 freq radios made for MTS usage, they had a special board that held the 4 extra elements (2 TX and 2 RX) that bolted in place of the TX PL encoder. I have a 64LHT 6freq.
	Trailing letters: (AK In our example) Additional version information. GENERALLY, the first letter is the radio revision, a trailing "K" means that it was shipped as a "Kit" with a speaker, mike, control head, control cable, fuse block, antenna, RF noise suppression kit, mike clip/pl hang up box, and installation kit (screws, tie wraps, etc). Fleets are ordered many times with the proper number of kits, and a few extra radios. I've seen one radio with an "ABK" nameplate.
	SP<some number> A special production radio was any custom version that was made as a modification to a standard radio, but in such a quantity that it wasn't a full production run. The exact same radio produced as a seperate complete production run would have an X prefix. For example, I have an ex-LAPD Motrac with dual receivers - you can see the control head in the old Adam-12 TV series. It is a X43HHT-3100C with an extended case, with the second RX in between the main RX and the power supply. I have an almost identical radio that was made for a midwest sheriffs department but it is a U43HHT-1130E-SP<some number> nameplate. I've also seen "X" radios that were indistinguishable from a standard radio. Such a mystery...