The Yaesu FT-1000MP MARK-V 'field'

摘要

When Yaesu introduced the FT-1000MP in the mid-1990s, it was as a lower cost, but high-performance, alternative to the massive FT-1000D. The FT-1000D, weighing in at nearly 26kg, was nobody's idea of a portable transceiver, but its performance was impressive, with a sturdy 200W PEP output. The FT-1000MP introduced a switch-mode power sup-ply, offering a 100W PEP package at a weight of some 15kg. With excellent receiver performance, it soon became the standard by which competition radios were judged, and has proved itself in many of the high-profile DXpeditions of recentyears. Some 18 months ago, the FT-1000MP MARK-V was launched, providing enhanced receiver facilities, and reverting to the 200 watt PEP output of the original FT-1000D. Unusually, the new MARK-V offered an option of running the PA in Class A for enhanced linearity, with a 75 watt PEP output power in this mode. To accommodate the increase in transmit power and the Class A operation, Yaesu removed the integral power supply and fitted a set of cooling fins on the top part of the case of the MARK-V to keep the larger PA cool. Power was supplied by a separate AC mains switch-mode power unit, providing both the 13.8 and 30 volt supply rails required. The 30-volt rail is no doubt needed to obtain optimum linearity from the 200-watt PA stage.