The CL-SIP353, AM/CW/SSB Transmitter Trainer, radiates a modulated signal on 3.57 and 4 MHz. These signals are modulated by selecting either two tones (750 kHz and 1800 kHz), 5 kHz, or voice modulation from a built-in microphone. All of the tone oscillators utilize crystal controlled synthesized circuitry. A four-crystal lattice filter provides for removal of the upper or lower sideband, with or without carrier suppression.

A unique feature of the transmitter is the built-in spectrum analyzer which enables the user to observe the RF signal using a frequency domain display. The carrier frequency can be observed before and during carrier suppression. Both sidebands can be observed, or either sideband can be filtered out. The spectrum analyzer section enables the viewer to completely view the characteristics of the carrier and sidebands, eliminating the need for very expensive commercial spectrum analysis test equipment.

The radiated output power is adjustable, so that the transmitter can serve as a generator. Transceiver operation is provided when two CL-SIP353 transmitters and two CL-SIP329D SSB receivers are used at one time. Each transmitter-receiver set operates on one of the two frequencies. The transmitter is arranged so that it can be easily studied in the laboratory. All of the controls are readily available and clearly marked. Test points are provided so that the RF Signal, frequency multipliers, and oscillators can be observed.