Published Resources Details
Journal Article
- Title
- A frequency recorder
- In
- Journal of the Institution of Engineers, Australia
- Imprint
- vol. 6, no. 10, Oct 1934, pp. 332-336
- Description
This paper, No. 492, originated in the Sydney Division of The Institution.
[Author David Forbes Martyn PhD ARCSc, a non-member, and Herbert Boyne Wood BSc BE StudIEAust were both radio researchers, Council for Scientific and Industrial Research.]
- Abstract
The principles and design of a semi-continuous frequency recorder, capable of recording several frequencies simultaneously, are described. The spectrum of notes to be recorded is scanned by a variable frequency oscillator. A revolving drum is mechanically coupled to the shaft of the variable condenser in this oscillator. When the frequency to be recorded differs from that of the oscillator by a fixed amount, the impulse which is sent through a low-frequency selector operates a relay and makes a mark on paper attached to the drum. The pen mechanism travels on a slow thread along a direction parallel to the axis of the drum, so that a semi-continuous trace is produced. Details of the construction of such a recorder are given. The principle is applicable to either low or high frequencies, and has application to the recording of ionospheric layer heights, and to the monitoring of the frequencies of radio emitters.