Kenwood TK-431
Like the Kenwood TK-941 mobile radio the Kenwood TK-431 handheld is also probably the worst choice for using on the amateur radio 33cm band. The TK-431 is just as bad as the TK-941 for amateur use because of the fixed -39MHz offset that is embedded in the firmware of the radio. There is only 1 version of the TK-431, they all have a high RF output of 2.5 Watts and low power output of 1 Watt (both are adjustable) and have 16 Systems and 10 Groups in each System- a total of 160 memories.
This radio is usable with 25MHz amateur repeaters as well as odd split repeaters; to get it to work on the amateur band you must do the "scan trick". The key is programming all the transmit frequencies in one System and in different Groups with the receive frequencies in another System in different Groups. This "scan trick" is identical to the TK-941 and is awkward to say the least. The other "gotcha" part of the "scan trick" method is that you cannot press the PTT until the repeater carrier has dropped out or the radio will be stuck on that System, which will be the receive frequency (repeater output), which if programmed correctly, has transmit disabled.
The Kenwood TK-431 radios are programmed with KPG-16D which is DOS based software and use the Serial DB-9 KPG-8/KPG-22 program cable- a USB programming cable will NOT work! Programming of the TK-431 radio is covered in the TK-431 "Programming" section of this website, also covered in the "Repeaters!" section is- using it to build a repeater!
Pictured below are two TK-431's. The radio on the left is original from the factory with no DTMF front panel. The unit on the right has the optional KDM-6 DTMF Front Panel installed. The antennas pictured on the units came from the newer and more advanced TK-481, as Kenwood used several different types of antennas on these units over the years. Antenna connector on the radio is a Male SMA connector, the connector type on the antenna being a Female SMA. The OEM battery pack that came with these radio's was the KNB-9A 7.2Vdc 1100mAh NiCd.
The Top panel of the TK-431 is compact and small. There is a 4 digit alphanumeric display. The "S" button on top of the radio is the Scan Button, the "A" button which is the Aux button is programmable as several functions such as High/Low power and Scan Add/Delete. The "SYS" key is the System key and is pressed to scroll through the 16 Systems (or as many as programmed) and the "GRP" key is the Group key and scrolls through the 10 Groups (or as many as programmed). Lamp key illuminates the display and the far left button is the Power button. Rubber Mic and SP is the dust cover on the Microphone/Speaker port.
