TS-990S Product Review

| enero 2, 2020

TS-990S Review

Kenwood TS-990S HF and 6 Meter Transceiver

TS-990S Review

Kenwood’s top-tier transceiver is loaded with features.

Kenwood’s top-tier TS-990S offers high performance and an extensive list of features. Its settings are highly customizable, and it looks and sounds terrific.

Reviewed by Rick Lindquist, WW1ME ARRL News Editor/NCJ Managing Editor

The long-awaited, top-tier Kenwood TS-990S is a magnificent behemoth — not surprising when you consider it swallowed an entire TS-590S for its subreceiver. Among its interior features are separate DSP chips for the main receiver, the subreceiver, and the bandscope to spread the workload, and hefty FETs operating at 50 V that help to moderate transmit IMD, keying sidebands and operating temperature while it’s cranking out 200 W. Words such as «bulletproof and «brick wall» barely begin to describe this receiver’s ability not to hear something you don’t want to hear.

This handsome radio sports an ambitious front panel, with no fewer than 110 buttons — including the one that actually turns on the radio — and 28 knobs, including concentric controls and the main and sub tuning knobs. A lot are dual-purpose — press, or press and hold. Given their tight proximity and the less-than-prominent off-white labeling, it’s very easy to, for example, mix up the cw t. and fil/sel buttons or turn the multi/ch knob when you really meant to grab the rit/xit knob.

User Friendly

Much of the transceiver’s personality resides in upgradable firmware, and the radio incorporates functions you’ve been relying on your PC to perform in the shack. Many critical functions exist only in code, so features can be added or improved (we updated our unit twice). Will the paradigm among manufacturers shift from introducing new hardware to developing better software for existing platforms?

The true beauty of the TS-990S is that it although it’s a «hardware» radio, it essentially lets you configure the radio that you want. The other side of that coin, however, is that you can invest considerable time getting it «just so.» For operators who desire one array of transceiver settings for casual operating and another for contesting or DXing, the TS-990S lets you save two complete transceiver configuration sets on a USB thumb drive — menu settings, audio equalization and routing, and other parameters. This fine tuning may be an enjoyable exercise — sort of like sitting in the driveway with your head under the hood, tinkering, with the engine of your high-performance sports car — but it doesn’t beat getting on the air. Zoom zoom!

On the Face of It

The ‘990 has two colorful LCD front-panel display windows, the larger measuring about 3.5 x 5.8 inches (Figure 1), the smaller «subdisplay» — directly above the sizeable main tuning knob — about 2.3 x 2.8 inches (Figure 6). Between them they can tell you everything you need to know. The displays are clear and sharp.

Connecting an external display may be a wise decision, because the main display contains an encyclopedia’s worth of status information and can include a bandscope and/or waterfall to boot — your call. It’s easy for info such as time and date to get «lost» in the display.

The smaller display duplicates the main radio’s frequency readout, contains a mini-bandscope, and, depending on mode, can graphically represent such things as filter and IF shift settings and provide a tuning aid for RTTY or PSK. The most unusual thing about this tuning display, however, is the virtual analog apron, or «skirt,» that recalls the Kenwood TS-520 era.

Scoping the Waterfall!

Repeatedly pressing the scp button will cycle you through a screen where the bottom half is blank, a screen where the band-scope takes up the bottom half, and a screen where the bottom half is roughly divided between a reduced-height bandscope and a waterfall that uses a color-coding scheme to indicate relative signal strength. The pattern rendered on the bandscope in the main display is smooth and sharp. Shadowing is a choice on the bandscope. Averaging lets you «settle down» the spectrum scope, making it a bit easier to spot signal peaks under certain conditions.

A lot of new TS-990S owners are enthusiastic about the waterfall. It’s available in all modes, although most hams are probably familiar with this feature from their digital mode software. It’s terrific but has its limitations. If you tune the receiver with the waterfall display in center mode, the waterfall stops! This means you cannot tune over to a signal on the waterfall that may not be making much of an impression on the bandscope but is showing clearly on the waterfall. This leaves fixed mode, in which the waterfall spans the limits of the current band. This also applies to center and fixed mode with the bandscope.

A mini waterfall shows up in FSK or PSK, though, and it does continue to flow as you tune, although its width is determined by the filter you have set. The bandscope works in all modes, and if you add the waterfall along the bottom half of the main display, the height of the bandscope reduces by two-thirds. Using the digital mode decode screen takes the waterfall down to about one-third its usual width, and the bandwidth is reduced to a maximum of 1500 Hz.

Span choices in center mode are 5, 10, 20, 50, 100, 200, and 500 kHz. Narrower is better on the bandscope, but you can easily distinguish signals by using the waterfall.

Touchy Feely

The TS-990S offers limited touch-screen capability. Touch a signal on the bandscope or waterfall, and the radio tunes to it. (The mini-waterfall is not a touch display.) This sounds better in theory. You must apply fairly firm pressure (compared, say, to an iPad), and tuning precision is only approximate at best, especially for narrow bandwidth modes (unless you have very pointy fingertips). It is far more precise with the waterfall. It’s a nice touch, however (pun intended), and I did find myself using it more as I got familiar with the radio. It’s also an excellent way to speed frequency changes. It’s possible to exact far greater precision using a touch stylus.

On the Menu

The TS-990S menu befits such a substantial radio, and navigation is straightforward. Press the orange-labeled menu button (it’s the only orange label), and it brings up the top-level menu, which is divided into groups 0 through 9. Each group covers a certain group of controls. For example, 0 is «Basic Configurations.» Highlight a group, and its abbreviated contents appear in (or stream across) the highlighted field. Kenwood has employed streaming-text menus in previous models but not in such a sophisticated presentation. Select the menu and you can navigate among the various parameters in that group. For example group 0, item 02 lets you adjust the font style for the frequency display (there are three choices). Many parameters are settable using the buttons below the menu screen or along the right side, although some are (also) adjustable by using the multi/ch knob.

All Things Being Equal

The TS-990S does not leave transmit or receive audio to chance. In addition to some «presets» for transmit and receive audio response (such as «High Boost 1 and 2» or «Formant Pass»), there are three configurable user settings.

Press the adjust key for one of those and an 18 octave parametric equalizer pops up, allowing nearly limitless tweaking within the confines of the overarching receiver and transmitter DSP filter settings.

The Roofing Crew

The TS-990S offers a wide selection of stock roofing filters. A selection of comparatively narrow filters ahead of the receiver’s first mixer is a more recent wrinkle in ham receiver technology. Narrow roofing filters are another hedge against the effects of nearby strong signals. The TS-990S can automatically select an appropriate roofing filter based on mode, but you can set it up to insert a 270 Hz, 500 Hz, 2.7 kHz, 6 kHz, or 15 kHz roofing filter.

The TS-990S subreceiver uses the same design as the TS-590S, reviewed in the May 2012 issue of QST, and its performance is very similar. The subreceiver operates as a double downconversion receiver 160, 80, 40, 20, and 15 meters with a mode-appropriate roofing filter selected automatically (500 Hz is the narrowest). For the other bands it’s a triple upconversion design with wider filters — 15 kHz at the 1st IF filter and 2.7 kHz at the 2nd IF.

Configuring Filters

A seemingly infinite variety of filter settings are available — roofing, IF DSP and AF DSP. The TS-990S also lets you perform some rudimentary filter shaping — sharp, medium, or soft. You can have either two or three filter settings (pressing the fil/sel button for either receiver steps through the choices for the current mode; pressing and holding the fil/sel button brings up the configuration table).

One screen configures all filter settings, greatly simplifying matters. Within the matrix for the selected mode are three (or two, if selected) choices for roofing, IF and AF filters, FIL-A, FIL-B, and FIL-C. The concentric hi/shift and lo/width controls adjust the upper and lower filter passbands inside and outside the configuration window. A graphical representation in the configuration window lets you view the effects of your individual choices.

Noise Reduction

As Kenwood has done with its other recent HF transceiver offerings, the TS-990S provides two noise reduction modes, each based on a different adaptive (ie, «self-learning») algorithm, but it’s really three types. Here’s the thing about adaptive noise reduction. Enabling noise reduction in the absence of a signal is not going to tell you very much about how well it works. You may hear some difference in the tone or background «sound,» but adaptive noise reduction systems need a signal to distinguish from the noise, and once they «figure out» which is which, the signal will emerge as if by magic. This was especially the case with the NR systems in the TS-990S. They work very, very well.

NR1 activates a spectrum subtraction-type noise reduction filter when the transceiver is in SSB, FM or AM mode. When receiving CW, FSK or PSK, however, the noise reduction system emphasizes the intermittent nature of CW. The second flavor of noise reduction — NR2 — which I long ago dubbed «crazed weasels» on my TS-480HX because of its squealy backdrop — is a SPAC (speech processing by auto correlation) system that, ironically, is terrific for CW reception, although some may find the digital artifacts bothersome.

Adjusting the NR1 control varies the degree of desired noise reduction, while adjusting the NR2 control varies the time constant for that noise-reduction system. You may experience popping and distortion on CW if you don’t have it set up just right and/or are not tuned dead-on. NR2 can sound worse in elevated noise situations (in some instances NR2 can overlay a crackling noise, but it really clears things up). You most likely would not want to use NR2 on SSB, but the TS-990S offers so many other means of fighting noise and interference you’re sure to find something that does the trick.

Using the noise reduction made a big difference when trying to hear relatively weak signals on 160 meters, which can be annoy-ingly noisy at my location. The preselector can also help to reduce noise by limiting the amount of broad-spectrum noise (2 or 3 MHz away) entering the IF passband. I was able to drop noise from about S-7 to S-1. You cannot use the preselector in combination with the preamp.

Speaking of noise, the adjustable APF (audio peak filter) is excellent to enhance readability in noisy conditions on CW — and the narrower the better in that mode,

although you can set three filter passband choices. It doubles as a twin-peak audio filter for RTTY.

I used the TS-990S during the August North American QSO parties — CW and SSB. I found the receiver quiet, yet I was easily copying signals that were S-0 on the meter. The noise reduction was very effective in both modes, with NR1 superior for SSB. Although it rolls off the high end somewhat, you can overcome that by changing the audio output equalization.

The ‘990 offers two noise blankers to, as the manual explains, suppress «crunching pulse noise.» NB1 is an analog noise blanker, while NB2 is a DSP noise blanker that works in the IF stage. Neither works in FM. The knobs to set the degree of blanking for both NB1 and NB2 are on a concentric set of front panel controls. You can enable one or both blankers.

In some cases, too high a level will result in some signal degradation. I found this especially true of NB2, although for severe noise (I ran a vacuum cleaner that generated S7 static), neither will get you that much closer to pulling out an underlying signal. As ARRL Lab Test Engineer Bob Allison, WB1GCM, points out, «Noise comes in many shapes and amplitudes and is difficult to quantify.» There is no standard test for noise blankers. The noise reduction systems are a better bet, I found.

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Kenwood TS-990S QST product review

Manufacturer: Kenwood USA Corp, 3975 Johns Creek Ct, Suite 300, Suwanee, GA 30024; www.kenwoodusa.com

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