Yaesu FT-101

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-277. Because of its reliability it earned its nickname "the workhorse".

The original FT101 Series (1971-1977) had dual conversion, with 5 MHz Receiver first IF, a very stable and linear 9 MHz VFO and 3.2 MHz 2nd IF. They had a 12BY7A tube driver feeding two 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 the antenna through a conventional pi network. This transforms 3000 ohm output impedance of the tubes to a low impedance, typically 25 to 200 Ohms. These tubes were common to television sweep circuits in the day, and were in practice just as rugged and reliable in amateur service as genuine transmitter tubes such as the 6146.

These rigs were extremely reliable, and various improvements were made over the model range, especially to the receiver, from Mk1, Mk2, B and E models (very few F models were ever produced). This was also one of the first all-in-one box rigs, as it had a built-in mains and 12V DC inverter power supply and even a loudspeaker, which made it ideal to use portable (it even had a carrying handle on the side). They also included two switched crystal-controlled positions for Novice license holders , who were restricted to crystal controlled transmission until the late 70's. This feature was also handy for fixed net operation.

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