Abstract: An RF phase and/or amplitude control device (40) has a digitally controlled attenuator (41) at it input to adjust the overall output level of the output. The device includes an in-phase power divider (43) for splitting up the input signals over two paths (I and Q). The power divided signals in the two paths are further power divided and shifted in relative phase at 180.degree. hybrids (49 and 50). The power divided and phases shifted signals in each path I and Q are selectively switched using switches (51 and 53). The selected and switched output is quadrative combined at a 90.degree. hybrid (55). This provides a single inexpensive device which can provide digitally controlled output signals which are either phase controlled or amplitude controlled or both.

Abstract: An improved marine radio telephone is disclosed having a microphone, display, speaker, and controls. The controls include switches and a keyboard located together with a display in a panel, a microphone conveniently located as to the front panel, and a push-to-talk switch incorporated in the microphone. A panel printed wiring board is provided for the control circuits. Digital logic circuits, including a special purpose microcomputer and a power supply mounted on a second printed wiring board, interface with the control circuits and display. The control circuits include circuit blocking means which can be readily removed to permit, when authorized, transmission on Coast Guard auxiliary channels 21, 23, 81, 82, and 83. A frequency synthesizer interfaces between the logic circuits and a transmitter and receiver. The synthesizer and receiver are mounted on a third PWB, and the transmitter is mounted on a fourth printed wiring board.

Abstract: An improved marine radio telephone is disclosed which has a housing having an angular opening suitable for either above or below eye level installation and a chassis having printed wiring board support members including a tiltable front panel support member for adapting the front panel to correspond to the position of the housing when mounted therein and a rear support member for supporting the transmitter board and heat sink for improved heat dissipation. The front panel includes a keyboard having keys for selecting digits 0 to 9, an emergency channel, and weather channels, a display for displaying the channel selected, control knobs for volume and squelch control, and switches for power and U.S.A. or international channel selection. The printed wiring boards include a front panel board, a digital input/output and power board, a frequency synthesizer board, a receiver board and a transmitter board. The front panel board sends operating signals to and receives outputs from the other boards.