MSF5000 Information Page

Model Number Decoding:

  This information is directly from the Digital-Capable Instruction Manual. Digital-capable implies the ability to run secure (encrypted) communications. Secure is NOT possible or available on 896 MHz stations; the Digital-Capable station for that band is called Analog Plus. (Motorola 896 MHz stations do cover the 900 MHz amateur band.)

First six characters (before the hyphen):       (the bottom row shows the most common or popular values)

Housing Power [1] Band Series Voltage
B: Base 0: no TX 0: below 25 MHz CL: Analog A: 12DC Ext
C: Compa 1: under 0.75w 1: 25-54 MHz CX: Dig.-Cap. B: 120AC
N: Rack 2: 6w 2: 66-88 MHz GF: Analog Plus C: Battery
  3: 15w 3: 132-174 MHz RL: Limited [2] D: 120AC or 12DC
  4: 40w 4: 406-512 MHz RU: Canada [3] G: 120/240AC or 12DC
  5: 70w 5 : 806-960 MHz [4]   K: 120/240AC
  6: 100w 7: 1.5 GHz    
  7: 135w 8: 280 MHz    
  8: 260w      
  9: over 260w      
C 4, 6, 7 3, 4 CL, CX, RL B

[1]: While the power shown is the maximum power for that range, the stations are typically rated for, or operated at, lower power levels. For example, a C64 is rated for 80 watts, a C74 is rated for 110 watts as a base station but only 85 watts as a repeater, and power range 8 is actually 225 watts for VHF and UHF stations, and 150 watts for 800/896 MHz stations. Not all power levels are available for all bands.
[2]: From the MSF5000 Instruction Manual update: "The MSF Limited line of base and repeater stations is identical to the standard MSF5000 model line with one exception: very few factory installed options are available. All other specifications, hardware, and software are identical." This means an RLB station is the same as a CXB station.
[3]: These stations are also digital-capable and seem to be identical to the CX and RL models.
[4]: Both the 800 MHz and 896 MHz MSF stations are in band 5, it wasn't until after the MSF line that the 896 MHz units became band 7.


Last six characters (after the hyphen):       (the bottom row shows the most common or popular values)

Squelch Ch Spacing # Ch Control Version Variation
1: CSQ 0: wide 0 [1] 0: None A: older R: Rack Mnt
2: Data 1: 25 kHz [2]   1: Data B: newer T: Repeater
3: PL 2: 12.5 kHz [2]   2: No Ctrl   (blank): Base
5: Connect Tone 4: Extender   3: Local    
6: DPL     4: EXT local    
7: Programmable [3]     5: DC [4]    
      6: Tone [4]    
      7: DC & Tone    
      8: TAC RX [5]    
7 1 0 5,6 A,B (blank),T

[1]: Even though it specifies zero channels, the stations can have three channels, and with additional code plug memory can handle 16 channels.
[2]: This position officially specifies the channel spacing, however it also indicates the modulation acceptance and deviation of the station. VHF, UHF, and 800 MHz stations are 5 kHz bandwidth, but can be programmed on 12.5 kHz channel increments. 896 MHz stations are 2.5 kHz bandwidth. This same meaning holds true for the analog (CLB) stations and is one way to separate 800 MHz from 896 MHz, since both use "5" for the band specifier.
[3]: Programmable squelch means the station can do carrier, PL, or DPL on any channel, and the transmit mode can be different from the receive mode.
[4]: The digital-capable TTRC (Trunking Tone Remote Control board) can be jumpered and configured in the field for DC or Tone.
[5]: TAC is Motorola's receiver voting system ("Total Area Coverage").


A typical model number, C74CXB-7106BT, decodes as follows: Compa-station, UHF, 135w (maximum, typically 110w), Digital-Capable, 120VAC power, programmable squelch, 25 kHz channel spacing, tone remote control, revision B, repeater.

As always, there are exceptions and violations of the model naming convention. If you see the letters "SP" followed by two digits after any model or part number, this means the station has been modified for the original customer to perform a Special Purpose, so components may not be stock.

Selected Station Ratings and Specifications:

Range Freq (MHz) Power Levels (Watts) Deviation TX BW [3] RX BW
VHF-1 132-158 6, 25, 75, 125, 350 5.0 kHz 26 MHz 2 MHz
VHF-2 146-174 6, 25, 75, 125, 350 5.0 kHz 28 MHz 2 MHz
UHF-1 403-435 6, 15, 30, 75, 110, 225 5.0 kHz 8 MHz 2 MHz
UHF-2 435-475 6, 15, 30, 75, 110, 225 5.0 kHz 8 MHz 2 MHz
800 MHz [1] 35, 75, 150 5.0 kHz 18 MHz 4 MHz
896 MHz [2] 75, 150 2.5 kHz 6 MHz 5 MHz

[1]: Transmit 851-869 MHz, receive 806-824 MHz.
[2]: Transmit 935-941 MHz, receive 896-902 MHz.
[3]: The transmit bandwidth is significantly less when equipped with an internal filter/duplexer.


High power stations (those running more than 125 watts of transmitter power - C8 and C9) need 46 inch tall cabinets and have two power supplies and two RF power amplifiers, although one is considered a driver for the other. All low power stations (those running 125 watts or less - C2, C3, C4, C6, C7) can fit into a 26 inch tall cabinet.

The standard 800 and 896 MHz stations are always repeaters; they can not be reconfigured as base stations to talk to repeaters in these bands. "SP" versions could be ordered for use as base stations however.

System deviation is normally set for 4.6 kHz on VHF, UHF, and 800 MHz systems. It is normally set for 2.3 kHz on 896 MHz systems.

Receive sensitivity is 0.25uV for 12dB SINAD except for UHF which is 0.35uV. A value of 0.5uV for 20dB quieting is also shown for all bands except VHF. Actual performance is usually a lot better. For example, my UHF stations reach 20dB quieting at 0.3uV.

Band 5 covers both 800 and 896 MHz stations. The model number does not specify the VHF or UHF range (1 or 2). You need to locate a part number on the RF tray or read the station with RSS to determine this. In general, for assemblies that are range-specific (power amplifiers, IPAs, front end assemblies, mixer coils, VCOs), the last digit of the assembly number indicates the range: 1 or 2. Look for small stickers with part numbers anywhere on these components. The location varies; some assemblies will have part numbers stamped on them.

People have managed to get range 1 UHF stations to operate at the low end of range 2, but to do it properly would require modifying everything that processes RF, and with parts no longer available, this would be nearly impossible. Similarly, an 800 MHz station will not operate up at 896 MHz.

Note that stations with the internal filter/duplexer and/or triple circulator have their output power de-rated considerably, due to insertion loss; so a UHF station could run at 110 watts as a base station, but only 85 watts as a repeater. The following information was extracted from tables in the instruction manual:

Rated Transmitter RF Power Level
Model Std. F/D Circ. Both
C23CXB 6 3.5 4.5 3.0
C43CXB 25 15 20 12
C63CXB 75 45 60 35
C73CXB 125 75 100 60
C93CXB 350 N/A 300 N/A
C24CXB 6 4 3 3
C34CXB 15 10 9 8
C44CXB 40 30 25 20
C64CXB 75 55 45 40
C74CXB 110 85 70 55
C84CXB 225 140 N/A N/A
C45CXB 35 23 30 21
C65CXB 75 50 60 45
C85CXB 150 100 125 90
C65GFB 75 50 60 45
C85GFB 150 100 125 90

1. See the chart at the top of this article for a breakdown of model numbers.
2. Power levels are in Watts. N/A = Not Applicable.
3. "Std." is the power level for stations with a single circulator (standard in all power amplifiers) and no internal filter/duplexer.
4. "F/D" is the power level for repeaters with the internal filter/duplexer.
5. "Circ." is the power level for stations with a triple circulator in the power amplifier.
6. "Both" is the power level for stations with an internal filter/duplexer and a triple circulator in the power amplifier.

The receiver IF stage operates at 10.7 MHz on VHF and UHF stations. It operates at 21.4 MHz on 800 and 896 MHz stations.

The transmit VCOs operate at the carrier frequency on VHF and UHF stations. They operate at one half of the carrier frequency on 800 and 896 MHz stations and the signal is doubled in the IPA and injection amplifiers. These stations also use what Motorola calls a Mosaic IC synthesizer. This will have significance only if you're programming a station for the first time. The receive VCOs operate similarly but the resulting frequency is lower than the carrier frequency by 10.7 MHz on VHF/UHF or 21.4 MHz on 800/896 MHz stations.

896 MHz stations have Flutter Fighter and compander circuits in them, which are equivalent to the HearClear circuitry found in other 896 MHz radios. They can NOT do secure communications. The 896 MHz RSS-programmed stations are called Analog Plus (GF) and these are, in all other respects, digital-capable.

Here is a short summary of the major differences between the two model series:
Analog (CLB) Digital-Capable (CXB, etc)
Older, less desirable Newer, more desirable
Usually less expensive Usually more expensive
Programmed via EPROM Programmed via a serial port
Uses suitcase programmer Uses a PC, RSS and a RIB
Long reprogramming cycle Short reprogramming cycle
Can't do secure (encryption) Can do secure (encryption)
No 7-segment LED display 3-digit 7-segment LED display
Mechanical potentiometers Electronic potentiometers
Multiple remote control boards One set of boards for all apps
Limited diagnostics Extensive diagnostics
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