Note
Ham Radio, Mar 1971, p. 74.
Ham Radio, Jul 1971, p. 85.
Space One RTTY demodulator has a number of interesting features, including heavy a duty loop supply, regulated power supply, an electronic keyer stage supplying plus and minus voltages with provisions for adjusting to 1.0 mA when driving diodes, as well as both 850 and 170 shifts, selectable from the front panel.
The circuit uses integrated-circuit amplifiers and high-voltage transistors for keying the loop supply.
The Space One uses standard tones of 2125 and 2975 Hz, has metered tuning (indicator lamps available as option), and provides a spare socket for the addition of a three-pole Butterworth bandpass input filter if local conditions warrant it.
The basic unit is completely self contained, including loop supply and FSK driver, and is ready to connect between your receiver and printer.
Several extra features are available at optional extra cost, including receive and standby indicator lamps, auto receive without motor-control relay, and auto-start plus motor control relay.
References
Brief description. Ham Radio, Mar 1971, p. 74.