Kenwood TS-140S All-Mode HF Transceiver

Technical Specifications

General Specifications

• Frequency Range (TX): 160, 80, 40, 30, 20, 17, 15, 12, and 10-meter amateur bands (includes WARC bands).
• Frequency Range (RX): 500 kHz to 30 MHz general coverage receiver.
• Operating Modes: LSB, USB, CW, AM, and FM.
• Tuning Steps: 10 Hz / 100 Hz / 9 kHz / 10 kHz / 1 MHz.
• Antenna Impedance: 50 ohms nominal (SO-239 connector).
• Power Requirement / Current Drain: 12.0 to 16.0 VDC (13.8 VDC nominal reference) / Max 20A in Transmit, 1.5A in Receive (no signal).
• Memory Channels: 31 total memory channels.
• Frequency Stability: Less than ±10 ppm.
• Dimensions / Weight: 270 x 96 x 270 mm (10.6 x 3.8 x 10.6 inches) / 6.1 kg (13.45 lbs).

Transmitter Section

• RF Output Power: SSB / CW / FM: 100 watts | AM: 40 watts.
• Modulation: SSB: Balanced modulation | AM: Low-level modulation | FM: Reactance modulation.
• Carrier / Unwanted Sideband Suppression: Better than 40 dB / Better than 50 dB.
• Spurious Radiation: Better than -50 dB.
• Microphone Impedance: 500 ohms to 50 kohms (8-pin locking round connector).

Receiver Section

• Circuitry Type: Double conversion superheterodyne.
• Intermediate Frequencies (IF): First IF: 40.005 MHz | Second IF: 455 kHz.
• Sensitivity (10 dB S+N/N): SSB / CW (0.25–30 MHz): < 0.25 µV | AM (0.25–30 MHz): < 2.5 µV | FM (12 dB SINAD, 28–30 MHz): < 0.5 µV.
• Selectivity:
  • SSB / CW: 2.2 kHz (-6 dB), 4.4 kHz (-60 dB)
  • AM: 6.0 kHz (-6 dB), 12.0 kHz (-60 dB)
  • FM: 12.0 kHz (-6 dB), 25.0 kHz (-60 dB)
• Image / IF Rejection: Better than 70 dB.
• RIT Variable Range: ±1.2 kHz.
• Audio Output Power: More than 2.0 watts (into an 8-ohm load with 10% distortion).

Key Features & Factory Options

• Noise Blankers: Built-in dual-mode variable pulse noise blanker (NB1) and a dedicated "woodpecker" interference blanker (NB2).
• IF Shift: Passband tuning alignment control for rejecting adjacent-channel signals.
• CW Filters: Supports optional narrow drop-in crystal filters such as the Kenwood YK-455C-1 (500 Hz bandwidth).
• Computer Control: Requires the optional IF-10C internal interface board for basic CAT system control.

Station Role

The Kenwood TS-140S holds an honored legacy placement in the W8USR gear archives. While modern software-defined rigs anchor our primary operating deck today, this compact workhorse remains configured as a high-reliability, all-mode backup HF base station asset capable of delivering a full 100 watts of RF output power across all traditional HF bands if called into service.

History with Radio W8USR

The Kenwood TS-140S is a cornerstone piece of W8USR station history, having served as our primary HF rig at the center of the radio desk for a ten-year span. Throughout its decade of frontline operation, this rugged transceiver anchored our daily traffic nets, logged countless contacts, and proved to be an exceptionally dependable performer. Today, it remains an essential part of the station collection, preserved to celebrate its years of dedicated service to our amateur radio operations.