From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Specification document detailing the design and features of a Wave Analyser.
| Identifier | ExFiles\Box 138\1\ scan0305 | |
| Date | 1st June 1938 guessed | |
| TF.{T. Fisher}455. 2. DESIGN The Wave Analyser is a superheterodyne valve voltmeter with a very sharply tuned intermediate frequency amplifier. The test signal is mixed in a balanced rectifier bridge with a carrier signal adjustable in frequency from 35 kc. to 50 kc. This frequency is adjusted so that the sum of its frequency and that of one of the components of the test signal equals 50 kc/s. This signal is passed through a highly selective two section quartz crystal filter and calibrated attenuator to a direct reading valve voltmeter. FEATURES The balanced modulator comprises a rectifier bridge giving at least 50 dB{Donald Bastow - Suspensions} suppression to the carrier and unwanted sum frequencies. The calibration is standardised against any power supply by adjusting the set gain control until the same deflection is obtained when a voltage is applied direct to the valve voltmeter and a fixed proportion of the same voltage is applied to the input. The beat oscillator is engraved to read directly the difference between the oscillator frequency and 50 kc/s. A linear rectifier may be switched into the input circuit for tests on radio frequency carrier envelopes. The two stage 50 kc. crystal filter provides a selectivity such that the response is down by more than 50 dB{Donald Bastow - Suspensions} at 50 c.p.s. off tune. The power supply is from batteries which are housed inside the instrument in a separate compartment. | ||