evolution, not revolution
Having long been a fan of Kenwood's TS-820S, I looked forward with great anticipation to the arrival of its successor, the TS-830S The 830S, I knew, promised a number of improvements and additions, among them more flexible receiver controls, smaller size, and the capability of operating on the three new WARC bands, I was both surprised and pleased that Kenwood chose to produce a new radio with a tube-type final amplifier, given the current trend toward solid-state finals. My general impression, after living with the TS-830S for about six weeks, is that Kenwood has kept the best features of the 820S, improved the weak areas, and added controls which make the rig more fun to operate.
On receive, the TS-830S covers all nine ham bands, present and future, from 160 through 10 meters. Sensitivity is rated at 0.25 uV, and side-by-side comparisons with other hot receivers show the 830S to be their equal in this area. Typical of Kenwood gear, the audio is superb, even when heard through the small internal speaker, Kenwood engineers must borrow a colleague from the company's high fidelity sound department when designing the audio stages of their ham equipment.
Some of the most obvious differences between the 830S and the 820S involve receiver features. While the basic dual conversion design scheme with i-fs at 455 kHz and 8 83 MHz remains intact. Kenwood has given 830S owners an impressive array of easy-to-use receiver controls, some of which are not present on the 820S, Three of these controls deserve special mention.
Foremost among these is the Variable Bandwidth Tuning (VBT) control. VBT allows you to change the width of the i-f passband from the normal 2.4 kHz all the way down to 500 Hz, if desired. Among other things, this control makes possible some serious CW operation, even without the optional crystal filters. The narrowing of the passband is accomplished by slightly raising the center frequency of one i-f filter, while slightly lowering the frequency of the second i-f filter. The net result is the narrowing of the i-f pass-band with no change in the center frequency.
The i-f shift function is a holdover from the 820S. This control actually moves the center frequency of the receiver passband by ±1.2 kHz When used alone, it allows you to shift the whole passband up or down slightly to avoid bothersome interference. What really makes this function a winner, however, is its use in conjunction with the VBT control By narrowing the passband and at the same time shifting it, some rather remarkable feats of reception can be accomplished. On phone, weak signals which might otherwise be buried by off-channel garbage can be brought up to intelligible levels On CW# it's possible to reduce the passband width to 500 Hz using VBT, then adjust the Shift control to select one of three or four CW signals, all without touching the tuning dial It's not as complex as it sounds, of course, taking a lot less time to do it than to describe it.
Notch filters are now standard issue on several modern transceivers. Each manufacturer seems to have a different idea about what hams want on this score. As a result, we have several different types of notch filters on current rigs, all of them useful in their own way. Kenwood's notch on the 830S is moderately deep —a bit better than 40 dB —and very easy to find. It does a good job on all single-tone type (carrier) interference and is especially beneficial during phone operation. It has proven less useful than expected on CW, mostly because there always seems to be more than one station I want to notch out. The notch filter gets only a small fraction of the use that the VBT and Shift controls get.
Once you are past the three controls mentioned above, the receiver portion of the 830S becomes more familiar.
Standard equipment includes a good noise blanker with adjustable threshold. The threshold level is a rather touchy adjustment. tubes from undue wear and tear Once learned, tune-up is a 30-second procedure.
The speech processor in the 830S is an rf clipper with two stages, one in the VBT circuit and one in the i-f. A small front-panel knob al lows adjustment of the compression level. This setting is rather critical, with about 10 dB of compression on voice peaks being about right. More than 10 dB of compression results in a less-than-pleasing voice quality. Incidentally, when headphones are being used, you can listen to your transmitted audio by pushing the "MONI" switch on the front panel, just to the left of the main tuning dial I find this indispensable in properly setting the compression level,
VOX controls for gain and delay are also located on the front panel, with anti-VOX on the rear panel The range of adjustment is wide enough to accommodate almost any micro phone you're likely to use with the 830S A high impedance mike is recommended.
The 830S features semi-break-in operation on CW, with the VOX circuitry and controls performing the task Hams with electronic keyers should be advised that the 830S employs negative keying, with —65 V at the key jack.
As the 830S is delivered from the factory, the three new WARC bands are enabled only on receive. Getting the rig to transmit on the WARC bands is a relatively simple procedure, requiring the clipping of diodes on the rf circuit board.
Kenwood's instruction manual for the 830S contains all of the basic operating information, a small section on maintenance and alignment, and little else. Hams planning to do any serious work on their 830S will be advised to pur chase a service manual from Kenwood. The lack of even a rudimentary "Theory of Operation" section in the manual is especially annoying, particularly to anyone attempting to write a review of the rig! The manual does contain a set of small but serviceable schematics, although you may need a magnifying glass to read them.
On the Air
On the theory that competition is an excellent test of machines as well as men, the 830S was pressed into service in the CW section of the 1981 ARRL DX Contest. The rig was operated, mostly on 20 meters, for 48 straight hours Since our 830S is not equipped with CW filters, we debated whether it should be used at all. We finally decided to try it, cranking the VBT control to the minimum bandwidth of 500 Hz, in an effort to get the selectivity needed for contesting. The results were very gratifying Not only did the 830S go the whole weekend without missing a beat, but also it turned out to be a fine CW rig even without the accessory filters. I imagine that dyed-in-the-wool CW operators will opt for the crystal filters, but even without them, the 830S does a nice job.
One thing becomes clear after you've operated this rig for a while. That is that Kenwood did some heavy thinking about how best to "human-engineer" the TS-830S. Take the knobs on the front panel, for instance. There are 5 distinctly different shapes and sizes. The result is that your mind quickly becomes attuned to seeking out the "small, flat knob" when selecting a meter function, or looking for the "tall, round knob" when going for the VBT. This difference in physical appearance is coupled with a very thoughtful layout, in which the most-used controls are placed in the most convenient positions. Compared to brand-new radios from other manufacturers, and even compared to the old 820S, the TS-830S gets high marks on human-engineering.
What we have here is an HF ham rig that is evolutionary, as opposed to being revolutionary, Kenwood obviously wanted to produce a worthy successor to the 820S, and they have done so, with a price tag that is lower than the 820S. The aspects of the 820S that endeared that rig to its admirers have been retained in the 830S, while more modern receiver attributes have been added and the layout of controls improved a great deal. If, in these days of the solid-state avalanche, you still feel more comfortable with a pair of nice, friendly 6146Bs, then Kenwood has a radio for you — the TS-830S. It's destined to become an industry standard.
Jeff DeTray WB8BTH 73 Magazine 1981