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The Kenwood TS-440SAT
The Kenwood TS-440 is one of the legends of ham radio. Over 600,000 of these
radios were produced in the early eighties (this number has been disputed, so I
am doing some more research - if anyone has verifiable production numbers I
would appreciate the information and the source), giving it the largest production
numbers of any HF ham radio. For its day, this was a cutting edge radio. It was
entirely solid state, including the finals; it had a pair of internal VFO's, so
that an external unit was not required for split frequency operation; it worked on all bands from 10 to 160,
and it was capable of computer control. One great feature, which has since
become standard on HF radios, is continuous receive on all SW bands. In the case
of the TS-440, all frequencies from 100 KHz up to 30 MHz can be received. With
the MARS modification, transmission on these frequencies is also possible. It
was also, for the day, compact and of light weight.
The Kenwood covers all of the HF bands (160 through 10 meters), traditionally referred to as the Short wave bands. The bands range, roughly, from 1.8mhz to 30mhz. The Kenwood can receive continuously on all frequencies, but will only transmit into the ham bands, as it comes from the factory. There is a switch which will automatically put the radio on ham bands only, for transceiver operations, or change it over for full coverage receive only.
My particular radio has been modified to transmit continuously on all frequencies - by a former MARS user. I did not do this myself, but bought the radio in this condition. In order to stay legal, once I have been granted my general license, I will have to be careful about which frequencies I transmit on.
The unit was microprocessor controlled - also a big deal back in the day, and had a digital read out, and direct frequency entry, as well as the more conventional tuning dial. A CTCSS unit was available for working repeaters. There was also a voice unit for announcing frequencies and changes - very eighties. A built in auto tuner gave it the last word in multi band operating convenience, and it was rounded out by a complete line of accessories.
I have included an ad from the day, taken from 73 magazine. The price new was $1200 - in 1986 dollars. This would be well over $2000 in today's money. The filters and accessories I have would add up to another $210. This was a top of the line, innovative radio. You can see the excitement, and the pride of innovation, in the ad.
This is also an all solid state radio, including the finals. This is common today; but was a new thing back in the early eighties. Previously there had been hybrid radios, with some solid state components or boards; but still using tube components, usually for the finals. For the most part, solid state is far superior to tubes, though there has always been some argument from technophiles about the suitability of solid state finals. Many consider a tube final to be better sounding, with a superior signal and more flexibility than a solid state final. Audiophiles have similar feelings about hi-fi stereo amplifiers designed around tubes. Whatever truth there may be to this, solid state finals, that is to say finals that use transistors instead of tubes, are the norm these days, though tubes are still used in high power linear amplifiers.
The main advantages of solid state finals are their reduced weight and power consumption, as well as their smaller size. They are also less expensive, and lend them selves to easier production processes. In addition, a transistor is physically much more robust that a tube. A tube, with its glass body, is quite sensitive to impact, and really quite delicate. Those of us old enough to remember them also recall that tubes have a tendency to burn out. Where a transistor can last decades, or even the life of the device, tubes burned out regularly, and were designed to be replaced regularly, much like tires or brake pads on a car.
The ad reproduced to the right (love those old ads, when I can find them) indicates some of the new promise of the new all solid state radios. A full function, multiband, HF radio, that was light of weight, and could be taken anywhere and easily set up was a quantum leap. Most HF radios of the day, weighted forty or fifty pounds, compared with the fourteen to sixteen pounds of the new TS-440. Additionally, operation in the field was a rough business, and the delicate tube internals of the older style radios could be damaged, loosened, or could fail for lack of replacement tubes, should a tube burn out in the field. There was also the matter of power consumption.
The tube models tend to
use much more power. The final Kenwood hybrid (TS-520) used 5 amps when
receiving, compared to 1.9 amps on the TS-440. Pure tube radios could use even
more. Largely this was due to the need to bring a tube up to a certain
temperature, which also meant that the frequency produced by a tube final could
drift as the temperature was reached, and would also drift if the temperature
should change. So most operators would allow a warm up time (usually of thirty
minutes) for the tube finals to settle down before beginning operation. Solid
also did not require a tune up when changing bands, though with the old tube
type finals, antenna matching and SWR worries were not quite so important.
Still, there were (and are) some advantages to the old tube type finals, which I
hope to go into in another essay on this site.
The TS-440 is an HF (high frequency) radio. There are presently 10 HF amateur bands. These bands have a total of 2.85 MHz of bandwidth. The rest of the shortwave bands are given over to commercial broadcast, military, maritime, and various other services. The TS-440 was set up for the nine bands available during its production, but the MARS/CAP modification permits access to the newer 60 meter band - though some care must be taken to transmit within band when doing this. The MARS/CAP mod is described below, but essentially permits transmissions on all frequencies within the radios' design limits.
The HF bands extend from 3 MHz to 30 MHz, and are what are commonly called the short wave bands. These are the original ham bands, and have the longest history, highest range, and largest variety of equipment. These are the bands you think of when you consider ham radio. There are the bands on which you can regularly work the entire world.
The most popular amateur mode on HF is SSB, though AM and CW (Morse Code) are also used. There are also a number of digital and fax modes available. Due to the width of its signal, FM is rarely ever seen on these frequencies, except for some use on 10 meters. A band plan is shown below. unlike band plans for VHF/UHF, the HF band plan is officially enforced by the FCC, and is a matter of international law.
Initially, this radio was operated out of a 5/8 wave CB antenna, designed for groundless marine use. The antenna worked well enough on ten meters, pretty well on twenty, and was even tunable on 40 (though I shudder to think about how inefficient it must have been). Eventually, I wanted something longer, better, and horizontally polarized, so that I could do some DX. As I was a typical space constrained apartment dwelling ham, I had to go with something small. I ended up with a Cliff Dweller - popularly known as a Slinky antenna.
This is a pretty neat idea, and one of those simple solutions which makes everyone say "Why didn't I think of that ?" The Cliff Dweller is a coiled wire antenna, suited to use on 10-80 meters, though my antenna tuner seems to be able to get me occasional use on 160 meters also. The antenna itself looks like a pair of Slinkys, sprouting out from the sides of a regular balun, with a coax connection going down to the radio. The coiled wires can be used extended from 12' out to their full coiled length of 50'. This is a reasonable choice for an apartment dweller, and can be used indoors or out; very nice. A tuner will have to be used, of course, but this is pretty much a given for anyone attempting to use a single antenna for multiple bands. The physical length of the wires, if they were to be straightened out, is a full 130'. So technically, this is a coiled 80 meter antenna. It is possible to simply buy a 130' long wire antenna, but I love the whole idea of the Cliff Dweller, and have no wish to try and find a 130' run for a wire antenna. I purchased the antenna from USA2WAY over the net. There are some companies which sell knock off units, but this is the original, and is claimed to be the best, though others make their claims too. At any rate, the purchase also gives me a membership, of sorts, in a user group, and access to a number of technical resources.
I had been reasonably happy with the antenna. It performed well enough, across most bands, and it was better than nothing. My auto tuner seemed a bit confused by it on some of the odd bands (12, 17, 30 meters), and took a bit of time to tune to it on 10 meters. With a manual tuner, the antenna tuned right up on all bands, with no problem - at least as far as visible SWR. The Cliff Dweller was initially strung along the ceiling of my apartment library, and was extended out to about 20'. I had considered running a length of wire, along the eaves of my apartment building, but did not wish to risk eviction from my building. This is the dilemma which most ham operators find themselves facing these days. It is not an easy matter to find space, and get permission, for a decent antenna, when living in an apartment, or condo complex. Though these places abound with power lines, TV antennas, and satellite dishes, most managers, and owners are poorly informed about ham radio, and find it easier to restrict, or forbid outside antennas for any such "non-standard" uses. The joys of city living.
The Cliff Dweller is now stored away. I am, in the process of updating my antenna system, in preparation for my General license. I am stringing wires in my full and unencumbered attic (25' x 30'), to run a dual cobweb antenna system. These will be fed by twinlead, and will pass through an aircoil balun before being fed to my radio. I will put up a page about this after I finish. The first cobweb will be of traditional design, and will measure eight feet on a side. This antenna gives excellent performance on all bands from ten to twenty meters. The second cobweb will cover bands from thirty to sixty meters, and will be over twenty feet on a side. The two antenna arrays will be side by side; but the design makes them very resistant to interference with each other. One very big advantage to a cobweb is that, unlike a standard dipole, it has no nulls. These antennas lay flat in my attic, and are horizontally polarized - perfect for HF, DX, and working the various forms of skip.
For 80 and 160 meter I am considering a helical dipole, or perhaps a loaded antenna. I also may consider making due with tuning up my 40 or sixty meter portions of my cobweb. Between the air coiled balun (very near the transceiver), and the low loss of my twinlead feed, this may be possible without too much compromise in efficiency. When resonant, these antennas are said to be 95% efficient. When combined with twinlead and a good balun, the efficiency of the entire system can be as high as 90%, or perhaps a bit higher.
The balun is an classic Heathkit model, and is of a type not much in favor these days. Air coil baluns are larger than today's solid core units; but in many ways are much better. They do not heat up, and allow for a bit more flexibility. This particular design, with the twin coils in a case, and a twin lead connector on one end and a standard coax connector on the other, permit me to use my radio's internal auto tuner.
One very nice thing about these balun boxes is that they can be easily set to 1:1 or 1:4. It appears that a 1:1 setting will work best for a cobweb. This is because a cobweb has a native impedance of 48 ohms. For information on why this is true, visit my cobweb antenna page (when it is finished). It is basically a bent dipole, which should have a native impedance of 12 ohms. Making the elements of twin lead, and then shorting the twin lead at a particular point turns this into a folded dipole, as well as a bent dipole. This quadruples the impedance to 48 ohms. Thus, no impedance matching must be done by the balun; It need only function as a choke. With twin lead feedline, even this is almost not needed.
I had purchased a G5RV; but it is not very efficient on most bands, and also has a strange radiation pattern on the higher frequencies. it also requires at least 70 feet of coax to be run as feed line. This tells me that the antenna is radiating off of its coax shield, which can be a source of TVI, and can give an even stranger pattern. I will probably end up using it as the platform for my multi fan dipole short wave receiver antenna. In a receiver, such things are not quite as important, particularly if there are a number of other antenna elements.
The G5RV has an efficiency that varies according to band; but is never much higher that 25%. Only at 20 meters, and perhaps 80 meters, is the antenna even remotely efficient. I know these are fighting words for many who consider this antenna a legend, but the proof is at: http://vk1od.net/antenna/G5RV/index.htm .
A number of features may be changed/added, by clipping or inserting diodes on the control board. You may have seen these on other places on the net, but I include them here for reference:
Diode options: There are a bunch of configuration options controlled by clipping or inserting diodes on the back of the control board. You get to it by taking the top and bottom covers off (a bunch of silver screws), loosening the front panel (4 flat-head silver screws, NOT the black ones). Then you have:
Opening the radio and performing mods.
The control interface is a convenience, and allows for easy programmed operation, as well as an almost unlimited number of memories. A signal interface (also known as a data interface) will open up a whole new world. Once a signal interface is installed, the ham operator will have full access to:
A control interface can be added quite easily, either by purchasing self contained kits by Kenwood, or other manufacturers, or by getting the parts yourself. However you go about accomplishing this, you will need to make the modification shown above, to the inside of the radio, unless this has already been done by a previous owner, and then add an adapter box to the outside. This combination will allow you to hook the radio up through your computer's RS232 serial port. Once connected, there is a fairly wide range of software out there for controlling, logging, and automating your radio.
The internal modifications consist of the installation of a pair of chips. These are shown in the schematics as IC 54 and IC 55, and install easily into sockets already present in the radio, on the back of the control unit circuit board. These chips can be bought, with instructions, from Kenwood as the IC-10 Interface Kit, or as kits by aftermarket retailers; they can also be bought via mail order, or at any good electronics store:
IC 54 is a uPD-8251-AC Serial Communications Interface.
Commonly called an 8251A
IC 55 is a TC-4040-BP 12 Stage CMOS Divider.
Commonly called a 4040
Installation of these chips enables an ASCII interface (TTL levels). This interface is accessible through the 6-pin DIN connector ACC-1 on the rear of the unit. Though this may be connected directly to certain computers, or through certain interface cards, most users will need the addition of an outboard converter box to connect to the more common RS232C port. With the IC-10 interface, or equivalent, installed, the output at ACC-1 is as follows:
Signals are TTL levels (NOT RS-232)
Baud rate is 4800 (1200 Opt.)
Format is ASCII Serial; 1 Start, 8 Data, 2 Stops
The Baud rate may be changed to 1200 Baud by removing jumper W50 and installing a jumper from the left pad to the center pad as viewed from the front of the radio. This will become obvious once you have the radio opened up. Many other Baud rates are possible, just look at the schematic.
Digital technology has moved so fast, over the last couple of decades, that radio manufacturers can be forgiven for failing to recognize the coming advances, and the potential of running signals through a computer. Up until the last dozen years or so, the average home computer was just not powerful enough to do much, in regards to processing audio signals, or extracting digital information from them. The early units also tended to be expensive, and to need expensive interface cards. Sound cards, as we know them today, were almost unheard of before the mid nineties. The early sound cards were also difficult to install, temperamental, and could be hard to add outside devices to. I know this from personal experience, because, in the early nineties I attempted to get digital audio into my old Windows 3.1 computer, a frustrating and fruitless effort.
There are three ways to
get a clean signal from and to, the TS-440. When I say clean signal, I mean a
signal that is at a steady level, and not affected by user settings. They are
from the FSK jacks, the ACC-2 13 pin connector (shown above), and the remote
connector. FSK jacks were meant to be connected to dedicated terminals for
teletype style communications. The FSK connectors are the easiest to use, because
they require standard RCA style jacks. The remote connector was meant for use
with a linear amplifier, and the ACC-2 was designed for data connection. The
remote is suitable only for reception, and it's receiver in pin was set up to
permit a reception path that did not pass through the amplifier.
The outboard converter box changes the signal from TTL to the more common RS232C serial form, adapting the voltage, and acting as a noise suppresser. It also adapts the six pin DIN connector to the more common D connector used by the RS232 port. Kenwood calls it's model of outboard converter the IF-232C. The outboard converter is plugged into ACC-1 on the back of the radio, presuming that the IC-10 or equivalent has already been installed. The computer may then be plugged in, via an RS232C port, to the converter box, and suitable software installed. The radio may now be completely controlled via computer.
These have not been produced by Kenwood in years, but are widely available from third parties. the most popular units are those made by PIEXX. Some companies produce simple adapter cables; but many of these do not include the required isolation circuitry.
I have a traditional IF-232C outboard controller, made by Kenwood in the eighties. it is smaller than it appears in photos, measuring 5.2 x 1.5 x 4.5 inch. The unit requires 13.8 VDC @ 150 Ma. In addition to matching levels, the box also serves as an optoisolator. It is compatible with all of the Kenwood radios from the eighties and nineties. This includes the TS-440, the TS-811, the TS-711, and the TS-60s. IT is also compatible with the SW receivers made in the eighties and nineties. The back of the unit has connectors for the power adapter, a standard D25 connector for connection to a computer, and a round six pin connector for hooking up to the ACC1 port on the radio. There is also a covered opening for future expansion.
Internally, the unit is pretty simple, by today's standards. A single circuit board holds the optoisolators, a couple of chips for the RS-232, and the various transformers, capacitators, and regulators needed to provide them with correct voltages. The IF-232 Interface from Kenwood is a 1488 and a 1489 chip in a box. These are an RS-232 Quad Line Driver and Receiver. The 1488 needs 12 vdc + and - supply. The 1489 requires +5 vdc. These lead out to a standard Kenwood six pin connector. A close look at the board, just above the six pin connector shows what look like circuit traces and holes for the installation of another six pin connector, along with the caps that are used as buffers. This is right by the placement of the plugged hole in the back of the unit. I am not certain if this was ever intended to run more than one unit, and how the two units might be switched (perhaps in software by unique radio identifiers)" but this holds out some interesting possibilities.
The DB-25 connector that goes to the computer RS-232C port is not as common as it once was. At one time, it was standard for most computers to have a pair of com ports, one with a DB-25 and one with a DB- 9. If you happen to have a computer set up in such a fashion, then a standard DB-25 cable will work. Otherwise you will need a DB-25 to DB-9 com cable - also pretty common. Today, the DB-25 is used almost entirely for the printer port, with the com port using a DB-9. Even this is not so common any more. Most computers use USB exclusively these days. A really new computer may need either a USB converter, or a com card.
Six Pin Signal Comments
1 Gnd Signal Ground
2 TXD Serial Data from Radio to Computer
3 RXD Serial Data from Computer to Radio
4 CTS Computer Ready; (Radio Input)
5 RTS Radio Ready; (Radio Output)
6 No Connection
Pins 4 and 5 may be left Unconnected.
For those that need to make a cable to convert DB-25 to DB-9, I have included pinout info below. As always, I recommend just buying the cable, as they are cheap enough, and making one can be a pain. Still, for those who want to homebrew, here it is:
The manual for the IF-232C is available here.
A number of software packages are available, and I go into
a bit more detail on my page about Porky the computer.
However, once you have gotten your signal interface, and your control interface
set up, you might want to try the DXLAB series of freeware. This is a series of
applications which are able to run your computer, log your contacts, calculate
usable frequencies for specific locations, and determine propagation affects of
sunspots. These programs can also generate great looking maps, and display your
contacts on them, decode, and encode RTTY, and PSK, and who knows what else. The
whole suite can be found at: