Note
Ham Radio, Jun 1971, p. 72.
Ham Radio, Oct 1973, p. 86. (Echo III)
QST, Apr 1974, p. 134.
QST, May 1975, p. 169. (A little more info)
QST, Oct 1975, p. 146.
The first commercially available repeater sold specifically for the amateur radio market.
The Echo II(III) contained a receiver, transmitter, and the carrier-operated circuitry necessary for repeater operation. Also included were a 117 VAC power supply with a battery backup for emergencies. An onboard trickle charger kept the batteries topped up when they weren't in use. Transmitter output was typically 15 watts and a crystal filter in the receiver's front end helped fight desensitization. The Echo Ill could be used over a frequency range of 140 to 175 MHz.
Receiver sensitivity: better than 0.2 uV
Solid state - no relays
Multiple frequency operation - remote selection capability
Protected against antenna short or open circuit or mismatch
Deviation 5 kHz adjustable to 10 kHz
Desensitization less than 0.25 uV at 200 kHz separation - negligible at 300 kHz
Power 12–15 volt operation, 40 mA receive, 1.5A transmit
Terminals provided for all necessary controls and monitoring
References
Brief description. Ham Radio, Jun 1971, p. 72.
