Yaesu Musen Co. Amateur Radio Equipment in Australia During The 1960's

by Greg Whiter, VK4IG (Ex VK3CA)

Shown below is part of the circuit diagram of one of Sako Hasegawa's first Yaesu Musen Co. products (the very first was in fact the model FL-10/40*), a 5 band crystal controlled 40 watt input HF SSB transmitter he called the FL-20.

FL-20 Circuit
The partial FL-20 circuit above shows a 6BQ6 in the PA stage while the block diagram below indicates a 6DQ6 tube was used. Although the block diagram was copied from an FL-20 advertising brochure, the author suspects that "6DQ6" is a typographical error. The crystal controlled FL-100 did however use the heavier duty 6DQ5 in its PA.
FL-20 Block Diagram


Shown at right is a rather poor photo of the first piece of Yaesu Musen equipment to be brought to Australia, Fred Bail's own FL-20. It is a later Mark II version and can be seen next to an FV-50 companion VFO for the FL-50 SSB transmitter. Although this photo was taken in May 1966 Fred had owned this FL-20 since 1963, having brought it back from Japan following a trip there. The author currently owns this particular original FL-20, the very first piece of Yaesu equipment to ever come to Australia as well as the only FL-20 ever imported into Australia to the author's knowledge.  Fred Bail's FL-20
FL-20 Mark II
The photo above depicts a Mark II version of the FL-20, 20 watt PEP input HF, 5 band crystal controlled mechanical filter SSB transmitter. This is the same (apart from the small White knobs) as the first Yaesu Musen Co. transmitter to be brought to Australia by Fred Bail, VK3YS, for his personal use, in 1963.
FL-20 Brochure
Shown above is an extract from an FL-20 advertising brochure giving general technical specifications of this early Yaesu transmitter.
Front panel Drawing
From the same FL-20 advertising brochure are, above, a drawing of the front panel layout and, below, a drawing of the internal component layout. Note that, unlike all later Yaesu valve equipment, which used solid state rectifiers, the FL-20 still used a valve rectifier (5U4GB) in it power supply.
FL-20 Internal Drawing
FL-20BTransmitter By the mid 1960's Yaesu Musen Co. had its F-Line on the market which, at that time, consisted of the FR-100B receiver, FL-200B transmitter and FL-1000 linear amplifier. Also, aimed mainly at the Japanese novice operator, was a powered down version of the FL-200B, the FL-20B. Shown at left, it used just one PA valve with much reduced voltage on it's plate to provide 10 watts PEP input power.

* The FL-10/40 was a monoband 40 metre 10 watt mechanical filter SSB transmitter, Yaesu Musen Co's first product.

Fred & Jim Bail Shown left are
Fred Bail,
and Jim Bail,

At right are depicted
various Bail logos.

Bail Radio & TV Service Logo
Bail Electronic Services Logo, early version
Bail Electronics Services Logo, late version

Fred Bail passed away in the late 1970's, Jim Bail passed away in the early 1980's. Following Fred's passing their company was sold to Stan Roberts of Teletramel, who continued to run Bail Electronic Services into the early 1990's from the Victorian country town of Wangaratta.

The author would be happy to hear from anybody who has very early Yaesu equipment, such as FL-20 Mark's 1 and 2, or FL-100B Mark's 1 and 2. By way of some background information on the author, GregWhiter VK4IG, (ex VK3CA) was employed by Bail Electronic Services from the late 1960's through to 1977. Following this period he formed the company GFS Electronic Imports, GFS Electronics and then Portable Masts Australia Pty Ltd, of which he is a director today.

Any comments on this web site should be directed to the author, Greg Whiter at :

Next Page - Photo of Bail's early 1970's staff
Other Pages at this site, include: FL-100B, the first Australian Yaesu radio, F-Line of the mid 1960's,  FL-10/40 Details, FL-20 Circuit and photos, BES 1974 Staff Photo, Yaesu/VK3YS/VK3ABA QSL Cards, FL-50 Magazine Review and photos, Photo and details of Yaesu's first SSB Transceiver, the 1966 released solid state FT-100, FT-100 Trouble Shooting Guide is shown HERE, the 1968 released FTdx400, The Yaesu Museum (German Site)

Other web articles by the same author   The Chronological History of the Development of Radio
Origins Of The Handie Talkie
he History Of Clark Masts
The Early History of GFS Electronics

Any comments on this article should be directed to the author, Greg Whiter at: GregWhiter@portablemasts.com.au

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This page was last updated 05-04-2023