by Bill Clarke WA4BLC
Top-of-the-line radios are expensive, and the prices seem ever increasing Kenwood-Trio, however, attacks the high price of high quality HF gear with the TS-140S.
The TS-140S is the first low-cost HF transceiver produced by Kenwood in several years. It is light weight, small-sized, full featured, and all solid-state. Although a fine hg for mobtle operation, many 140s will find warm homes in shacks.
The TS-140 is Kenwood gray, of course. It weighs in at just 13 pounds. Its 36 front-panel controls are laid out in a handy manner, and the display is much more than just digital frequency read-out.
The nice features include RTTY, Packet. AMTOR and optional FM operation; UP/ DOWN microphone buttons for scanning and tuning; full-break keying; selectable AGC; 20-dB attenuator; speech processor: VOX; and adjustable RF power output control
The built-in speaker, although quite small, provides very nice audio.
Before operating the TS-140, I read the entire instruction manual, especially concentrating on the memory operations I highly recommend a new 140 owner to do this.
Every button and control operates easily and crisply on the TS-140S. At first the main knob tuned too lightly for my taste, but a simple twist of the knob's collar weighted properly.
The rear panel has the VOX controls, antenna and ground connections, key and external speaker jacks, and several accessory plugs for remote control, optional antenna tuner, and other functions.
The blue-colored digital frequency read out is part of the 140's display panel. I find it easier on the eyes than some of the red LED or green
LCD displays seen on other radios. Other information (VFO in use, memory position. RIT, modeT scan, etc.) shows on the mam display in an assortment of red, blue and yellow colors. All are very readable,
Kenwood still includes the option of a 10-Hz read-out on the digital frequency display, The user can select this from the front panel. There is no need to open the rig and make any internal modifications.
The tuning rate is 10 kHz/revolution of Ihe VFO tuning control This seemed too fast, and five kHz per turn would be suitable. Fast tuning is done by using the Memory Channel knob. Tuning rate for the Memory Channel knob is 10 kHz per click, which is 240 kHz per turn. At first the idea of using two knobs for luning seemed complicated. After the initial
30 minutes of use, however, I found it quite natural
The memory scheme used on the 140 is a little complicated. There are 31 memories, broken into banks of single frequency, split frequency, programmed band marker, and scan. The manual explains clearly their use. I had no problem programming them from the very first entry.
The TS-140S has almost all the necessary filters built-in. Only the 500 Hz CW fitter is optional IF shift is included, which works well to augment filtering for interference reduction. It is detented at the zero point.
The receiver is very quiet and doesn't get too excited by background static. It is almost as quiet as the Ten-Tec Corsair, I found reducing the RF gain made receiving quieter when conditions were very noisy. This is normal with all sensitive receivers, and the 140 is very sensitive.
The 140 has two noise blankers The first attenuates "woodpecker" noise, and the other attenuates other pulse interference, like ig-
nition noise. They both are very effective, even with household noise generated by fluorescent lamps and some light dimmers.
The TS-140 has both band and memory scan. Scan speed is adjustable from the front panel The operator can also manually scan memories by pushing the UP'DOWN buttons on the mike
USB/LSB selection is made by the rig but may be over-ridden by the operator. The user can also select fast or slow AGC action.
Like most current rigs, the TS-140 has two VFOs, a nice touch for working SSB and CW splits. The two VFOs also allow split-band operation. Also, the 140 is easily modifiable for use on MARS frequencies. Modification is re* quired, since the CPU doesn't allow transmitting outside the ham bands.
The TS-140S sports semi- or full break-In keying. OSK operation was great It could be broken with a dit or two The CW note had good reports.
I received consistently good audio reports on SSB. Each indicated excellent quality voice transmissions. None stated I was overdriving the ng. All contacts were made using the standard microphone supplied with the radio.
I've Got Memories
The TS-140S has 31 memories to complement the two VFOs* The memories are changed from a knob on the front panel or with the microphone UP/DOWN buttons. A user can program the mode in all memories
There are four types of memories •Eleven single frequency memories are used for receive and transmit.
•Split frequency. There is a frequency in this memory for transmit and another for receive. This is most useful for 10-meter FM repeater operation, and split DX If the same frequency is entered for both transmit and receive, then a split memory will function as a normal memory. There are 10 split memories. •The programmed band marker. The user enters upper and lower band limits in this memory. A Novice, for example, may wish to enter 28.300 MHz and 28 500 MHz as the two band limits From that time forward, when that memory is selected, turning the VFO knob will change frequency, yet excursions will automatically be kept within the limits of the programmed band markers. Continuous tuning will cause the frequency to stop at the end of the programmed limit and restart at the other
end of the limit. There are ten programmed band marker memories.
•The last memory contains band scan limits These are the highest and lowest frequencies that will be scanned. Of course this memory may be used as a standard memory if both frequencies entered are the same. There is only one scan memory.
Inside the 140
The inside of the TS-140 is a complete departure from all Kenwood HF equipment built to date. The unit is made of two circuit boards and an RF deck. The latter hinges away from the main chassis for service.
The first thing I noticed upon opening the 140 was that there were very few interconnect wires. Most interconnections are handled with ribbon cable This results in a very uncluttered interior. At the side of the top board is a place to install the optionat CW filter.
The computer-style interconnections and well-planned circuit board will lead to excellent reliability. At the very least they promote easy service.
Bench testing is the only method of checking a transceiver's specifications against those published by the manufacturer. I completely checked the 140, and it met or surpassed all published specifications (see sidebar).
The following equipmeni was used in checking the performance of the TS-140S: Leader LDC 8243 Frequency
Counter Marconi Instruments 2022
Signal Generator Hewlett Packard 606 HF Signal Generator
Hewlett Packard 651A Audio Generator Bird 43 Wattmeter
Hewlett Packard 8551B/851B Spectrum Analyzer
Cushman CE-5 Monitor
Tectronics 475 Oscilloscope
Remember that the performance of currently available amateur transceivers generally exceeds the capabilities of the human ear, propagation, and atmospheric conditions.
The instruction manual for the 140 is complete and contains many charts and diagrams. It's generally easy to understand. A few instructions, however, are written incorrectly.
I was particularly disturbed at the incorrect instructions for IF SHIFT, Tuning Knob VFO,
and Mobile Antenna Tuning. Even worse was the mention of bonding the accelerator for mobile noise reduction. The latter could prove to be very dangerous.
Kenwood USA is now aware of these conditions. Hopefully they will soon improve their manual for the 140.
The 140 has no notch filter, but I didn't miss it. Past experience has shown me that notch filter controls are too sensitive to set quickly In lieu of built-in notch filtering. I use the Da-tong Automatic Notch Filter. The later is something no modern station should be without.
Keypad direct frequency entry is another modern innovation I have come to like on another rig (ICOM IC-761). I plan to use the Stone Mountain Engineering QSYer for key* pad direct frequency entry on the TS-140S.
The slide controls on the right side are delicate to operate, but they are usually only irregularly adjusted
Amplifier users need to open the rig and set a switch to the ON position. This switch activates the relay coil for Ihe remote contacts. Kenwood says they leave it in the OFF position to reduce operational noise. Even when on, however, neither the relay nor the cooling fan on the final amplifier is very noisy. Its operation is barely noticeable.
Many of the front panel selections provide feedback with beeps, which I found annoying. The beeps are CW for the modes and alarms. Blind operators may find this feature a bonus, however. Some can be turned from the panel. All can be silenced by an internal adjustment.
Would I recommend the TS-140S? Yes! It has all the necessary features of the heavyweights and is certainly a very capable transceiver, yet the price is remarkably low. Don't think low price means low quality. The 140's price brings the features and capabilities of expensive rigs to financial reality.
Would I personally purchase a TS-140? As a matter of factt I did.
Thanks to the folks at the Electronic Equipment Bank of Vienna. Virginia, for the loan of a new Kenwood TS-140S, and the use of their very complete test bench HI
WA4BLC regularly reviews amateur equipment for 73 Magazine.
KENWOOD TS-140 SPECIFICATIONS (as stated in the manual)