Note
73, Nov-Dec 1975, p. 73.
Visually identical to the Echo II.
The KLM Echo 70cm (or Echo 70) was a 10 watt solid-state UHF transceiver manufactured by KLM Electronics (Morgan Hill, California). Designed for SSB and CW operation on the 70 cm (432 and 435 MHz) amateur radio bands, it was notably one of the few commercial rigs of its era tailored for amateur satellite communications, such as OSCAR 7 (Mode B) and Phase III satellites.
– Frequency Coverage & Band Selection: Operates on the 432 MHz and 435 MHz amateur bands. Band selection is controlled via a rear-panel slide switch.
– Modes: Selectable Upper/Lower Sideband (USB/LSB) and CW. Mode selection is controlled via a rear-panel switch, while sideband selection is via a front-panel push button.
– Main Tuning & VXO: Features a large center knob calibrated from "01" to "47" in 20 kHz increments (providing 480 kHz of tuning range per band). Continuous fine tuning within each 20 kHz segment is provided by a center-detented VXO control with a range of ±10 kHz.
– Receiver Fine Tuning (RIT): An RIT control with roughly a 2 kHz range helps clarify received SSB signals.
– Receiver Design: Double-conversion design front-ended by a six-cavity helical resonator and FET RF amplifier for strong immunity to overload.
– "Auto Watcher" button, which automatically sweeps any 20 kHz segment for signal presence (indicated by a small red lamp when active).
– Rear Panel Connections & Controls: Slide switches for base band selection (432 or 435 MHz), mode (SSB/CW), and VFO selection (Internal / External VFO).
– Jacks for key, external VFO, amplifier control relay, external speaker, and power connectors.
– Power Output & Efficiency: Delivers better than 10 Watts RF output into a 50-Ohm load.
– Draws approximately 5 Amps during transmit from a nominal 12 V DC power source.