Kenwood's TS-140S is a high-frequency radio transceiver. The unit is designed to broadcast across all amateur radio bands from 160 to 10 meters. The TS-140S features front-panel controls for band selection, memory presets and band scanning. The front panel also contains a microphone input and headphone output, allowing you to perform all of the device's operations from the front panel of the unit.
The TS-140S can suffer from several issues ranging from poor performance to outright failure due to bad power supplies. The TS-140S is designed to run off a 12V to 16V power source, such as a car battery. Lower voltage ratings may cause the unit to transmit at lower power or to stop functioning entirely. The unit will typically display 14MHz USB on the main screen when the output voltage is low. Low voltage can be fixed by using a more powerful battery or a step-up transformer. The TS-140S can also lose power due to a blown fuse. The TS-140S utilises fuses to prevent damage to the equipment from excessive voltage or current. These fuses are located inside the unit and must be replaced when blown.
The front control panel of the unit has a number of different controls that can be confusing to amateur radio operators. Improperly setting these controls can cause the unit to fail to send or receive data. The SQL and RF Gain controls can be particularly troublesome. Decreasing the SQL control by turning it counterclockwise and increasing the RF Gain control by turning it clockwise improves signal reception. The unit must also be in the correct receiving mode. The mode buttons are used to cycle through different modes; if nothing is received on one mode, you can cycle through modes until the unit transmits and receives properly.
The TS-140S has several adjustable controls tucked inside of its case. To access these controls, you need to remove the four screws on the top of the case and the eight screws on the bottom of the case to open the top and bottom covers. Four more screws hold the subchassis in place. The inner adjustments can increase or decrease the microphone volume, the beep tone and the side tone. It has an interface to calibrate the unit's digital display. The inside of the case also features expansion slots for optional accessories for the unit.