Note
QST, Nov 1963, p. 7
The SME-1 (Sideband Multichannel Exciter) is a solid-state communications exciter manufactured by The Technical Materiel Corporation (TMC) in the mid-1960s.
Designed as part of TMC's family of solid-state transmitter control units, the SME-1 provides high-stability radio frequency generation and modulation for commercial and military HF communications systems. It interfaces with external power amplifiers to provide flexible multi-channel, multi-mode operation.
Frequency Coverage and Tuning: The SME-1 uses plug-in RF tuned converter modules (such as the TTRT series) allowing multi-channel frequency selection. Each converter module in the SME architecture accommodates two user-selectable channels.
Exciter output: up to 250 mW.
Heterodyne Architecture: It utilizes a double-conversion intermediate frequency (i-f) system with two distinct i-f stages at 250 kHz and 1.75 MHz.
Operating Modes: The exciter supports multiple transmission modes, including single-sideband (SSB—upper or lower sideband), CW (Morse code), AM equivalent (AME), reduced carrier (-20 dB), and MCW (modulated continuous wave).
Remote Control Capabilities: The SME includes standard provisions for remoting Upper Sideband (USB) and Lower Sideband (LSB) control switching.
Derivative Model (SMEE-1)
TMC also produced a specialized automated variant designated as the SMEE-1. The SMEE-1 was optimized for automated, single-conversion operation with TMC's "TechniMatic" auto-tuned transmitters:
Single Conversion IF: Replaces the SME's double-conversion scheme with a single 1.75 MHz IF stage utilizing dedicated dual balanced modulators and crystal filters for LSB and USB generation.
Automated Tuning Interface: Incorporates stepping switches, sequential control relays, and a backend multi-pin connector to pass channel selection data to a TechniMatic transmitter. During tuning cycles, it automatically mutes audio and injects a level-adjusted carrier sample to safely drive the transmitter's servo-driven power amplifier tuning networks.
Broadband Amplifier & ALDC: Includes an internal broad-band linear RF pre-amplifier stage, an auxiliary power supply, and Automatic Level Down Control (ALDC) input filtering.
