Abstract: Apparatus for imparting a delay to an input signal utilizing counter means comprised of a plurality of binary coded decimal counter stages connected in cascade. The high frequency input signal applied to the counter undergoes a divide-by 10.sup.N operation wherein N equals the number of binary coded decimal stages. Preferably, the least significant stage is adapted to be selectively and periodically preset to a binary coded decimal value different from its normal reset state to either increase or reduce the number of pulses required to cause the counter stage to read a terminal count to selectively either advance or retard the phase of the reduced frequency output signal developed at the output of the counter relative to the phase of the input signal applied to the counter in accordance with a preprogrammed value set into said counter stage.

Abstract: A telephone adapter for hands-free telephony, adapted for use with a telephone handset having structure including an earpiece, comprising: a transmit signal path comprising, in series, a microphone, amplification means, disabling means and a transducer; a receive signal path having means for amplifying sound energy from said earpiece, said receive path comprising, in series, a coupler, amplification means, disabling means and speaker means; bias means for maintaining said transmit path in an active state when no signals are present; and, means for interrupting said circuit paths in a complementary manner.

Abstract: Method and apparatus for comparing and/or adjusting the frequency output of a frequency source, which method and apparatus is greatly simplified, and permits adjustment within a relatively short time interval and at a precision whose known difference is less than five parts in the 10.sup.12.The rubidium-controlled oscillator employed by the major networks to produce the 3.58 MHz subcarrier signal is utilized as a standard. Offsets made available at regular intervals by the National Bureau of Standards are utilized to indicate the frequency differences between the network standards and the United States Frequency Standard (USFS).