50Watt HF Transmitter. Philips' 30 V H.7. transmitter, type S7Z 395/001 has been designed for telegraph (A1) and telephone (13) signals. The transmitter is continuously tunable throughout the 1*5 to 3° Uo/s range. There is a minimum number of tuning elements on the front panel because widmband circuits are used in the H.?. preliminary stages. In the above-mentioned frequency range a choioe can be made of 18 orystal-oontrolled frequencies. The transmitter oomplies with the Radio Regulations of Atlantio City with respect to frequency stability in ambient temperatures between 4-10*0 and +45*C. It is also possible to employ an oscillator connected to the transmitter. Modulation and remote oontrol of the carrier (push-to-talk operation) are accomplished via a 2-wire telephone line. The transmitter is housed 6* a single chassis and can be incorporated in a 19-in. cabinet. It Is suitable for operation in tropioal olimates.