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)
Last six characters (after the hyphen): (the bottom row shows the most common or popular values)
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:
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:
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.
is a short summary of the major differences between the two model series: