Note
QST. Feb 1978, p. 121.
The Racal RA6700 is a fully synthesized, tunable, solid-state communications receiver designed for all modes of reception over the frequency range of 15 kHz to 30 MHz. The internal synthesizer provides single-knob frequency control that allows rapid tuning across the complete frequency range with the feel and smoothness of a VFO, while retaining the accuracy and stability of the internal frequency standard.
in addition, the operator can select either a 100- or 10-Hz tuning rate, with the separate MHz control knob, permitting rapid changes from one end of the frequency range to the other.
The RA6772 incorporates the very latest techniques in mixer and signal path refinements t o produce improved dynamic range and to reduce intermodulation products, reciprocal mixing, cross modulation, blocking, and spurious responses to a degree that exceeds the capabilities of any other general-purpose receiver of the day.
The basic receiver will accommodate six IF filters; two may be asymmetrical SSB filters with either 3- or 6-kHz nominal bandwidths. Provisions are also available for additional filters if the standard 300-Hz, 3-kHz, and &kHz filters are not adequate.
During CW reception, the internal BFO provides ±3 kHz tuning range.
The receiver is ruggedly constructed to permit operation under extreme conditions. The internal layout permits easy access for servicing, all components being accessible without the use of extension leads or adapters.
The rear panel contains all input and output connectors, with many internal connections making possible the use of the receiver as the basis for a more sophisticated receiver system.
To enhance receiver versatility and flexibility for communications, surveillance, and direction-finding applications, a number of options and variations are available. In addition to the normal modes of reception provided in the basic RA6772, additional units can be added within the receiver to permit reception of ISB and FSK signals, along with AFC operation.
When configured for teletype, one or two machines may be directly connected to the receiver without the need for external power supplies.
The RA6700 receiver series is well suited for single- or multiple-receiver systems, with numerous options and configurations possible. As an example, the RA-6774 can be controlled by a computer, or, as in the case of the RA-6780, by either local or remote manual control