Yaesu FT-101 is a model line of modular amateur radio transceivers, built by the Yaesu Corporation in Japan during the 1970s and 1980s. FT-101 is a set that combines a solid state transmitter, receiver and a tube final amplifier. Its solid state features offer high-performance, low-current characteristics and its tube amplifier provides an almost mismatch-resistant transmitter and tuner stage. FT-101’s were made with plug-in circuit boards that could be sent to the dealer or factory for replacement or repair. Until then, modular design was unprecedented in the amateur community. This also explains the fact why so many FT-101's are still in use today. The rig was sold worldwide as Yaesu FT-101 and in Europe as Yaesu FT-101 and as Sommerkamp FT-101. Because of its reliability it earned its nickname "the workhorse".
Contents |
The 1971-1977 FT-101 types were equipped with an amplifier consisting of a 12BY7A pre-driver stage feeding 2 6JS6C television sweep tubes providing a nominal output power of 130 watts peak envelope power in single sideband, 90 watts continuous wave and 40 watts amplitude modulation. The 6JS6C tubes are matched to 50 ohms through a conventional pi network. This transforms 3000 ohm output impedance of the tubes to a 50 ohm feed system, provides harmonic attenuation, and easily matches to a variety of output impedances from 25 to 100 Ohms.
The 1978-1985 FT-101 types were quite different. They only had the HF, pre-mixer and oscillator units as plug in circuit boards. The IF and audio boards were connected by plugs to a centralized wire harness. Its power supply unit was directly soldered and fixed to the same wire harness. Although the newer types lost their fully modular circuit board buildup, their reliability and ruggedness were outstanding. They were equipped with a very sensitive receiver, a very linear VFO which made flawless operations in the AM, SSB and CW modes possible. Its tube amplifier still had the same 12BY7A pre-driver but the final tubes were replaced by 2x 6146B tubes, slightly reducing its maximum power output from 130W to 115W PEP SSB, 75W CW and 50W AM or FM.
The unit could receive from 10.0-10.5 MHz in order for reception of the WWV time and frequency standards. The unit could transmit and receive on the 160 m, 80 m, 40 m, 20 m, 15 m, and 10 m amateur radio bands. WARC band coverage is possible using aftermarket kits. Early models included the 11 meter band, once allocated to amateurs. Later models replaced the 11 meter position with AUX, and with the proper crystal inserted, would only receive the 11M band. However the early models are often used illegally by citizens' band (CB) operators. The B, E, and F trimlines include reception and transmission on the 160 meter band, as well.[1]
The unit can modulate using either upper sideband (USB), lower sideband (LSB), continuous wave (Morse Code), or amplitude modulation (AM). The power available in these modes is 130 W (SSB), 90 W (CW), 40 W (AM). The standard audio-frequency filter used for transmission passed 300 Hz to 2700 Hz.
Many station accessories were available including the FV-101 remote VFO,FL-2100 Linear Amplifier, SP-101PB Phone Patch with Speaker or SP-101 Speaker-only, YO-100 or YO-101 Monitor Scope, YC-601 Digital Display Unit, FTV-250 2 Meter Transverter, FTV-650 6 Meter Transverter, YP-150 Dummyload / Watt Meter, YD-844 Dynamic Desk Microphone and QTR-24 World Clock
Many models in the FT-101 series were manufactured in its timeline:[2]
Because critical circuit designs were kept to a manageable size, hams had no problem in offering circuit changes, isolating and repairing problems. This knowledge base was so active that in January 1972, Milton Lowens (call sign WA2AOQ), founded the International Fox Tango Club and the Fox Tango Newsletter. The Fox Tango Newsletters were published for 14 years covering the early FT-101s through the latest Yaesu transceivers in 1985.[3]