Cook Strait Swim

Radio Record, Volume IV, Issue 28, 23 January 1931, Page 30

Cook Strait Swim

Transmitter Tested

UCCESSFUL tests were carried out last week with the short-wave radio telephone transmitter which will be used in conjunction with the attempt of Miss Mercedes Gleitze to swim Cook Strait next month. The set has been constructed by two Wellington radio -engineers, Messrs. W. S. Green and H. C. Dixon, whose call signals are ZL2 GR and ZL2BO respectively. Reports of clear reception were reeeived from various listeners in the surrounding districts. The test was considered satisfactory, as the transmitting aerial was a very short one not far from the ground, and well wedged in among city buildings. The transmitter, a photograph of ‘which appears on this page, is 18 inches high, 144 inches wide and 12 inches deep, which makes a very compact assembly. The dependable range of this transmitter, using a wavelength of approximately 80 metres, is 500 miles. The power, 30 watts input, is supplied. by heavy-duty dry batteries of 400 volts. The microphone feeds into a }-watt speech amplifier. The speech amplifier feeds into a 14-watt mddulator which modulates a 10-watt oscillator. Radio telegraphy can be used if desired by the plugging of a key into the circuit, and the transmitter is set into operation by the pressing of one mul tiple switch which controls all circuits