Transmission of television signals over long systems requires a fine degree of equalization. An adjustable type of equalizer to supplement fixed equalizers is discussed. It provides both gain and delay characteristics in the form of harmonically related cosine shapes which are independently adjustable. The design and operation of the equalizer is explained on the basis of paired echo theory. The 336A equalizer used in the L3 coaxial system is discussed as an example of this equalization technique.

The spacecraft employs two microwave antennas for communications and a single VHF antenna for telemetry, beacon, and command functions. One microwave antenna centered at 6 gc is used to receive broadband signals from a ground transmitter while the other microwave antenna centered at 4 gc is used to transmit signals to a ground receiver. Each microwave antenna is composed of a large number of circularly polarized radiating elements equally spaced around the equator of the spacecraft and connected to the electronic receiver and transmitter by a complex precision feed system. The VHF antenna is a small multi‐element helix mounted at the pole of the spacecraft and radiates a linearly polarized signal. All antennas provide nearly isotropic antenna patterns with the axis of symmetry corresponding to the spin axis of the spacecraft. The antenna systems were constructed of light, but rugged, materials and passed extensive electrical, mechanical, and thermal tests.