Some Methods of Measuring the Frequency of Short Waves

Four methods are given for practical frequency measurements on short waves (10-50 meters 30,000-6000 kc) with an absolute accuracy of ±0.01 per cent to ±0.001 per cent and a relative accuracy of ±0.0001 per cent. Harmonic overtones are used in each method. The frequency standards are exclusively the luminous quartz resonators developed by Giebe and Scheibe, which are exceedingly useful and at the present time represent secondary standards constant to 1/100,000 so that continuous supervision with special calibration apparatus and chronograph is unnecessary. The indirect methods use fixed or variable fundamental frequency, while the direct methods use resonators whose response is indicated visually or acoustically. The methods were developed by Transradio A.G., Berlin, and are used by the transmitting and receiving stations in Nauen and Geltow-Beelitz.