BOS mobile radio

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      T 700
  Motrac MHT







was Motorola's most successful entry into the Land Mobile Radio market, it was the first mobile radio in the US (and possibly the world) to have a fully transistorised receiver. This meant it was possible to leave the receiver on, without running the car's engine for DC power.

The first variants, from 1958 (Models designated as "HHT":), used germanium devices in the receiver, and tubes in the sender.

Through the 1960's design improvements were made (With attendant changes in model nomenclature), to make the transmit exciter solid-state, change most of the transistors to silicon, and in the last
"LLT, MST, & MSN" versions (called "Motran"), the radio was 100% transistorised. (Motran attempted to make T/R switching all solid state as well. Motorola dropped this requirement when making cross-band Motrans).

LLT were only made up to 30 watt TX power in 2M, and 50 watt in 7/8M (The 30-50 Motran was 50 W, and as modified, it drove a varacter trippler to get the 30W @ High Band. With early RF transistors, a higher Voltage than 12V was needed in order to reach the desired power level, so a "T-power" supply was used in early solid state transmitters, eventually yielding to newer, 12V type transistors (MSN Motracs).

Manufacture of Motrac ended around 1972, yet many of them are still in service in North and South America. They were usually only changed when it became difficult to find replacement final tubes.

Motorola replaced them with a newly designed "Mocom", that shared some circuit features of Motrac, and "Micor", another very successful design which was even larger and heavier.
The Mocom series was the cheapie series. Some were front mount, 10-30W. For low band, the MOCOM 70 was basically a repackaged LHT except with an all solid state Tx.

The Micor was the top of the line until the Syntor series came out, with Mitrek being the replacement for the Motran series.

The museum example is an MHT,

probably the most common type for High band and for UHF. Its transmit power is 100W, receive mixer is a FET for better IMD performance. It needs ca. 30 amps from the (12v) auto current supply for transmit.

The museum's radio was used by the
NYPD (New York Police Department).
(see picture gallery)