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Preface This in-depth manual for the TS-480 was written by the engineers who actually planned and designed the product. It is our hope that this guide will serve to convey the joys of HF and all the benefits of owning and using the TS-480 to whoever reads this guide – whether you have already purchased a TS-480, an accomplished operator, thinking of buying a transceiver, or just thinking of taking up Amateur Radio as a hobby. We believe the TS-480 will appeal to everyone. CONTENTS ････
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Design Objectives Determination to create a unique transceiver The concept of a compact HF transceiver first saw the light of day with Kenwood’s TS-50. From then on, such equipment has become an essential part of the Amateur Radio world. Equipment has now evolved with the appearance of multi-band models. In developing this new HF transceiver, Kenwood has boldly chosen not to follow this path, because we wanted to develop a transceiver unlike any other available. If we had developed a produ
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Standalone control panel For mobile operations, a separate control panel is ideal, but what if the transceiver is also to be used as a base station? This was the problem we faced. With a large desktop rig, it is no easy matter to shift things around to find the best position, so perhaps it would be a good idea to have a separate control panel that could be moved easily. Also, a desktop unit has various kinds of cables connected to it. What with the heat the main unit produces and the noise
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Adding appeal to fixed station operations It is now increasingly common to see a PC sitting beside the transceiver in the shack, but we wanted to expand the interaction between computers and transceivers. It was with this in mind that Kenwood came up with the idea of an Internet remote-controlled transceiver. You may be away on a business trip, but you want to operate, or you may want to use a large Yagi antenna out in the suburbs from your downtown apartment. In these and many other ways,
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Development Objectives for the TS-480 Series The following is an explanation of our development objectives, distinct from the planning objectives. If asked about the origins of the compact HF rig, people outside Japan would no doubt think of the Atlas Series. Following the Atlas, a variety of different products appeared on the market, but it is probably no exaggeration to say that Kenwood’s TS-50 was the first in the category of the 100W (HF) compact all-mode transceiver. It is already mo
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Focusing on HF Raising power output and adding an antenna tuner are both moves in the right direction, but limiting the transceiver to the HF bands when the mainstream nowadays is HF~V/UHF would seem to be going against the tide of the times. Yet opting for the multi-band route inevitably leads to larger dimensions and higher prices. In this genre, price is an important factor, so by limiting the TS-480 to HF, we developed what is in fact a compact transceiver that stands apart from the co
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Circuitry ● TX circuits 200W final section Explained here is the circuitry for the 200W final section, the crown jewel of the TS-480 Series. This circuit is responsible for developing 200W output with a DC 13.8V power supply. Of course, various approaches are possible. The typical one would be to use a high voltage (28V or more) with the FETs in a push-pull arrangement. However, we did not adopt this approach since a DC-DC combination that raises the voltage to 28V exclusively for this pu
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Fig. 1 illustrates TX IM characteristics with 200W output at 14MHz, while the second graph (Fig. 2) charts high-frequency spurious emissions. Fig. 1: TX IMD (output 200W) Fig. 2: TX Spurious emissions 9
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SPS (separate power sources) [TS-480HX only] SPS is shorthand for “operating at 200W using two 100W 13.8V power sources.” To generate a 200W output from 13.8V requires a maximum (total) current of 41A. As previously explained, the TS-480HX employs a pair of 100W final amps. What the SPS design does is to supply these amps from two separate power supplies, as shown in Fig. 3 below. The use of two power supplies may appear inconvenient, but in actual fact this arrangement is quite practical.
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Failsafe device (some TS-480HX versions only) The use of two power supplies and two final amps in parallel is something that has not been tried before, and naturally there may be some anxiety on the part of the user regarding what would happen if just one of the power supplies suddenly failed. Such a situation would be handled safely, since the TS-480 series is equipped with several failsafe devices. Should a difference of 1V or more be detected between the two power supplies: “RX ONLY” a
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Fig. 4: 200W final section Fig. 5: 100W final section with antenna tuner 12
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FM circuit There were two approaches used for the FM circuit of the conventional all-mode transceiver. Either there was a dedicated modulation circuit using a 10.695MHz crystal, or the modulation was performed by the VCO on the 2nd OSC. The latter was not an option for the TS-480, and since the whole transceiver had to be compact, we did not adopt the former approach. How then is FM handled by the TS-480? What we have employed for the TS-480 is something that is rarely seen these days in h
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● RX circuitry Front end As explained in the section on development objectives, what distinguishes the TS-480 Series are incomparable features and performance that result from our focus on HF. Of special note are the dynamic range characteristics in the HF bands, demonstrating the fact that, despite the compact dimensions of this transceiver, there has been no design compromise. One of the circuits that is important in determining dynamic range is the first mixer. Now there are some compa
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How well does it actually perform? Fig. 8 is a graph illustrating the dynamic range characteristics when changing the separation of two interfering signals. For the sake of reference, results for the TS-480 are plotted against those obtained using other compact mobile transceivers (on the market) under the same conditions. Fig. 8: RX dynamic range Looking at Fig. 8, results higher up the graph indicate wider dynamic range. When the RX frequency is 14.100MHz, and for example there is s
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filter – reflects a difference in the manufacturers’ approach to design from the antenna to the 1st mixer. It is not just the mixer that determines the characteristics of the front end: all of the components between the antenna terminal and the mixer can have an impact. Despite the compact design of the TS-480 Series, its RX BPF divides up the 500kHz~60MHz range into 10 bandwidths. Since several coils are employed in this BPF circuit, small coils have to be used in a compact transceiver. W
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Jumpers for joy As with the TS-2000, something special has been provided for both the BPF ATT in the BC band and the regular ATT: The BPF has been equipped with an ATT in order to cope with powerful local broadcasting stations in the BC band. However, a jumper can be used to switch from NORM to DX, bypassing this ATT and raising sensitivity by about 20dB. The ATT accessible from the control panel defaults to 12dB, but by removing the CN4 jumper it is possible to increase this to abo
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Circuitry after the roofing filter Except for FM, the TS-480 has a double super: 1st IF is 73.095MHz and the 2nd IF is 10.695MHz. For FM, there is also a triple super as low as 455kHz. This is followed by analog detection and signal processing performed by the AF DSP in a standard arrangement. The AF DSP is not optional: it is equipped as standard. DSP features and characteristics are explained in the DSP section. Three newly developed optional filters are available for the 2nd IF. Previou
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Whereas the TS-570 provided only a single slot for installing an optional filter, the TS-480 has two slots, meaning that two of the three filters can be installed at the same time. And the process of installation itself is quite easy: there is no need to remove the main unit, since the option installation unit has been designed to be separately removable. The photograph in Fig. 12 shows the option installation unit. This can be used to install not only these IF filters but also a high-stabi
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Auxiliary Features In addition to the basic TX/RX circuitry already described, the TS-480 is equipped with a number of auxiliary features of considerable practical benefit. What follows is an introduction to some of these. ● Full compatibility with digital modes (data modes) PSK31 and RTTY operations can now be performed with ease using PC software. The TS-480 has been designed to make it easy to use such digital modes. External audio input/output terminals, separate from the mic and spe
