The FT-101 series of transceivers appeared initially in the
USA in small numbers in late 1971, and gained almost
overnight approval of amateur radio operators for their
quality of signal, flexibility of operation and the
professional attention given to workmanship and design.
Each Transceiver shipped is normally accompanied by an
instruction manual, a set of accessory plugs, a high
impedance (50K) dynamic hand mike, and two cables; one for
AC operation, the Other for DC power hookup. The exception
is the FT-101EX, which has no DC capability, although it can
be added by installing the DC-1 unit. The installation of
the DC-1 is also covered in this manual.
These specifications differ from the latest issue FT-101E
series only in the frequency range (which now includes the
160 meter band) so the owner of a vintage Yaesu FT-101
should not feel he was obsoleted too badly along the way,
but newer FT-101’s did include major circuit improvements.
For example, Yaesu engineers developed a major modification
that significantly improved the Receiver side of the early
FT-101, and after serial numbers 25,000 - all FT-101's came
from the factory with some different boards and circuits
than early models. This led to a situation where two
different models existed side by side, with the same FT-101
designation, so in this manual, pre S/N 25,000 units are
identified as "early", and post S/N 25,000 as "late". (We
only use the last five digits of the Yaesu serial number -
the Other numbers and letters are used for internal factory
The entire modification which made an "early" into a "late"
was developed and sold as an update kit, which included a 25
page instruction guide, complete with pictures and sketches.
Total confusion promptly occurred, with hams ordering the
kit (known as the MIR-1 Modification Kit) who unhappily did
not have the test equipment necessary to do the
re-alignment, or just plain lacked the "know how" to do such
major surgery on a sophisticated electronic assembly.
After fighting the flood for a few months, Yaesu withdrew
the kit from the open market, and today will only install it
at their factory.
There was no FT-101A produced, but when the second set of
major mods appeared, the new issue was designated FT-101B,
to emphasize its model change, including all of the updated
circuitry, plus adding a new band;
160 meters. All FT-101B’s and "E's" will work on the 160
meter band, but you may have to order a crystal, etc.
The FT-101B was superceded by the FT-101E, which included an
RF Speech Processor; the FT-101EE which omitted the Speech
Processor; and an "AC Base" version, FT-101EX which did not
have the built-in DC supply, Speech Processor, DC cord,
microphone, or 160m crystal.
Again, no FT-101C, or D versions reached production status.
Early FT-IOIE’s used a Speech Processor that had to be set
manually on each band for clipping level, which meant
considerable cover lifting for the amateur who switched
bands frequently. To eliminate this handicap, the processor
level control was combined with the clarifier pot using a
paddle knob. At the same time, the processor itself
underwent a redesign, and emerged as an extremely low
distortion producing RF processor, noticeably superior to
both previous Yaesu processors, and competitive units.