Figure 1 -- The elements of ccw communication over time.

The enable refers to the pressing of a manual key by the operator.
The dots, dashes and spaces of the enable are not precise in
length. The ccw keying shows the keying as done by the ccw keyer.
Note a dot or a mark is begun only at the beginning of the frame
period and continues for the full period. As received, the
signal is mixed with QRM and QRN. The difference between the dc
volta-es from the switching mixers of the two channels is a function

     In

of the desired signal. The integrator sums the power (voltage)
received over the frame period. This sum is sampled at the
end of the period and held for the next period by the hold.
The recovered modulation is used to key an audio signal of
a frequency convient to humans for decoding.