The TS-590SG is a compact 100 W radio for all HF bands incl. 6m.
In the tradition of Kenwoods top class transceivers, the engineers put special attention at an excellent receiver. With the TS-590S Kenwood follows a concept which is not new, but can be found more and more often with current transceivers: down mixing in the first IF. At receive frequencies from 160 to 15m (and at a bandwidth ≤ 2.7 kHz) the first IF is mixed down to 11MHz. This makes the use of very efficient filters possible, just because it is easier to make a good filter at lower frequencies. The result with the new Kenwood transceiver is an excellent blocking dynamic range and superb close-by signal selectivity. The dynamic range of the AGC is influenced only minimally from nearby signals, even at 2 kHz distance the receive still shows a range of more than 100dB. Two cascaded roofing filters in the first IF stage (first filter 6 kHz, second filter selectable 2.7 or 0.5 kHz) further enhance the already excellent receiver characteristics.
The AGC is controlled by a Digital Signal Processor (DSP) at the second IF stage (24 kHz). Here, several accurately aligned control loops produce a well balanced and fast AGC performance. The injections signal of the firxt mixer is generated by a DDS (Direct Digital Synthesizer). This results in a very low noise level, because the oscillator signal is also much lower due to down mixer. The net effect is a lower phase noise due to reciprocal mixing in the IF stage, lesss receiver noise. The receiver is very quiet, and with the precise adjustable AGC control even weakest signals can be detected.
But the IF DSP handles many more functions. A dual passband shift for SSB (LSB/USB) is very useful to 'cut' the signal out of the noise and QRM. At FSK, CW or SSB-data modes the DSP acts an IF filter with variable shift and width. Two of those programmable IF filters can be switched very quickly with an A/B switch, a very useful function when searching the band with a wide filter, and closing in on the DX signal with a narrow filter.
Other DSP functions are Auto and Manual Notch filters which are controlled automatically or manually depending on mode. A combination of analog and digital noise blanker cancels even the strongest pulse noise. Finally a two stage noise reduction offers exceptional quality to reduce constant noise and get weak signals out of the background.
The TS-590S transceiver has a solid aluminium die cast chassis. This is helpful to get the heat of the 100 W final amplifier to the outside. Two large and relatively slow fans are used for active cooling, the slow speed helps to reduce the noise from the fans. A built-in antenna tuner matches nearly any coax fed antenna. Selectable transmit bandwidths and a built-in equalizer result in a perfect audio modulation, regardless of the situation. Telegraphy enthusiasts can connect two keys at the same time, a paddle and a straight key (or a paddle and a computer keyer). The TS-590S offers full- and semi- BK operation, a memory keyer, automatic CW zero-beat tuning and much more. Digital mode users enjoy the direct connection between tzransceiver and computer by a USB interface, which also acts as an audio interface. A Data-VOX function is useable also via the ACC connectors.
Despite the many functions of the Kenwood TS-590S the operation of the radio is very easy. The most important functiosn are easily reachable by the front panel, less often used functions are accessible via a clever menu system. The LED backlit display can be set to two different colours (amber, green). A speacial feature of the transceiver is the USB connection. It allows the direct connection to a computer for CAT control and audio data, the transceiver behaves like an independent sound card. With this connection an extra sound card interface might become unnecessary. Kenwood offers a free software to program and control the radio (see Kenwood website).
The newer version TS-590S"G" benefits from the experiences collected when developing the flagship TS-990S transceiver. Improvements were applied not only to the receiver but also to practical functions like CW decode, and to cosmetic details as well.