My Yaesu Radios - The Solid State Models
In the 1970s, Yaesu began moving more and more toward sold state designs,
abandoning vacuum tubes. In the transitional phase, many models were
mixed or hybrid types that used vacuum tubes only in the output stage.
This was the design approach commonly used until affordable high power
transistors became available by the late 1970s. After that date, all
models quickly switched to entirely semiconductor based designs like
the ones shown on this page. There were great advantages to the use of
transistors rather than vacuum tubes: they produced far less heat, had
reduced maintenance requirements, and needed no high voltages. Because
of this, most of the later models did not incorporate power supplies, but depended on an external source
of 12 Volts (actually 13.8) at a peak of about 25 Amperes. Such
radios could easily be operated from batteries in automobiles, greatly simplifying
It seems to me that
the FT-107 culminated the design concept begun with the FT-101 series. This
radio physically resembles ones in that series and somewhat resembles the FT-901
and FT-102 models. The circuits are likewise similar also, except of course for
the output stages which in the FT-107 were entirely solid state. The FT-107 was
novel in another respect: it could be obtained in an off-white version, quite
unlike the dark cabinets used in most other radios. For those that preferred, a
dull gray version was also marketed. I purchased the radio shown here because I
found the light colored cabinet attractive. The radio acquired a certain cachet
because of the color, and I have seen it
referred to as the "white elephant."
Another radio of
about the same era, was the FT-7 and the FT-7B. These transceivers were
intended from the beginning primarily as mobile radios, having
mounting attachment thumbscrews on the side of their cases. The FT-7 was capable
of 10 Watts output while the FT-7B could provide 50W and had a few
other minor refinements. This particular model was diminutive in
comparison to other equipment on the market at the time and can be
considered a forerunner of the IC-706 and TS-50 mobile/portable
radios of a decade later. These were simple radios having none of the
upscale features of the larger transceivers, yet they remain much loved
by their owners. The FT-7B I obtained was dirty but otherwise in fine
condition and despite the years, its alignment was nearly spot on. As
an addition, I built the digital display seen here
from a kit which I purchased on eBay.
Perhaps the Yaesu transceiver that presented the biggest difficulty in restoration was the FT-ONE. This radio was introduced in 1981 as the flagship model in Yaesu's lineup. It remained on the market for five years but never became a best seller because it was priced at just under $3,000, a jaw-dropping figure at the time. It did offer for the first time some nice features--tuning by frequency synthesis, general coverage from 150 kHz to 30 MHz, internal memories, a wide range of filters (seen above), and bandpass width and adjustment controls. There is no band switch on this radio; instead, frequencies are selected by a combination of a keypad and a rotary control used to select one megahertz band segments. Unfortunately, this in the long term became its biggest drawback because keeping oscillators in the synthesizer aligned and on frequency proved to be a formidable task. Most owners of these radios have found that their units eventually had problems in frequency calibration and alignment. When I received the unit seen here, it could not be aligned and would not receive SSB properly. In the end, I had to modify the local oscillator board seen above in order to achieve acceptable results. Frequency readout accuracy was another problem and required some tricks to remedy. In case you are interested, i will be adding another page of explanation about how I resolved these issues soon. Check back later.
Another radio that I picked up for a modest price at a hamfest about in the early 2000s was the FT-900CAT. After restoration, I liked the radio so much it became my daily driver for several years. The letter C in the suffix refers to a Collins mechanical filter. The transceiver had an internal antenna tuner, which refers to the letters AT. The tuner is highly useful if you usually operate barefoot or with one of the older amplifiers. I was originally attracted to this rig by the availability of these options and by its small size. For a few years, it was the radio of choice for DXpeditions because of these features. This model was designed to be used as a base station or mobile. If used as mobile, it was possible to detach the control panel from the main unit as shown here, allowing the control panel to be placed near the driver while the larger and heavier main body could be placed wherever convenient and connected by means of a separation cable.
I acquired the FT-1000dx Mark V field because I had heard so much about the FT-1000 series; for quite a few years in the early 2000s it seemed to be the preferred transceiver among top-flight contest and DX operators. There were actually quite a few variants of the FT-1000 model and there were wide differences among them. My radio, the Mark V version, came at the end of the FT-1000 series production. There were, however, two versions of the Mark V model, one offering 200 Watts output but with an external power supply, and the other the "field" model providing 100 Watts output and having an internal power supply. These radios were extremely capable transceivers incorporating every imaginable feature integrated in their design. Provisions were made to accommodate many filter choices, and I was able to complete my set of filters as seen above through eBay purchases.
The final two radios I include here are current models. I purchased the FTdx3000 because I wanted a more up-to-date transceiver on my operating desk. I considered the FT5000 but was discouraged by the failure to integrate a spectrum display in the radio. Of course, with external units, that can be added, but I feel in this era a radio without a spectrum display is just not complete. I know some operators don't consider them very useful, but I rely heavily on these diplays to monitor band conditions. I also looked at FT9000, but was deterred by the expense and size. Finally, the FT-891 was purchased as a full-power portable radio that I might take on my overseas trips. When traveling abroad, especially for extended periods of time, weight and size become major considerations, and this radio is the smallest of all compact full-power transceivers. I sold my IC-7000 to purchase this radio because it weighs a pound less and is smaller in cubic size. It also has a more usable spectrum display, though it lacks color. Also, to keep size small, I built an adapter to enable the use of the small HT microphone you see in the photo above.
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