SELF

8

S.B. Karavashkin and O.N. Karavashkina

The main aim of this experiment was to determine four characteristics:

• the dependence of the received signal amplitude A_m   on the inclination angle of the polarisation plane of the radiator to that of the receiver;
• the dependence of the received signal phase  _m on the angle ;
• the dependence of the received signal amplitude A_m on the distance r between the radiator and receiver;
• the dependence of the signal phase delay _d on the distance r

  The first and second characteristics are necessary for the experimental check of the possibility to radiate/receive the transversal acoustic wave in gas, so as, though the amplitude characteristic per se corroborates the studied effect presence, but not completely. If the signal phase changes additionally by 180^?, when turning over the receiver polarisation plane, this will undoubtedly evidence the presence of a transversal acoustic wave.

  The second pair of the characteristics was included to this experiment in order to study the space behaviour of a transversal acoustic wave.

  Proceeding from the main goal of the experiment – to register the transversal acoustic wave – this experiment was planned as the fundamental. Consequently, the measurement errors corresponding to this condition, i.e. in limits 5 – 8 %, were considered satisfying.

2.2 Construction of the radiator and receiver of a transverse acoustical wave

As we said before, when preparing the experiment, we saw our task not only to radiate a transversal acoustic wave, but also to receive this radiation by the receiver responding namely to this type of waves. This was the reason, why the receiver and radiator have been made constructively identical.

A dipole system was naturally chosen as the base.

Therefore, to solve the task, we needed to satisfy the following main requirements:

• the maximal co-ordination of the oscillations of both halves of the oscillator;

• the maximal possible parallelism of the transversal acoustic wave radiation by both halves of the oscillator; both radiating surfaces had to be located in one radiation phase plane, to sum effectively the waves generated by the half-oscillators;

• the maximal possible parallelism of the transversal acoustic wave radiation by both halves of the oscillator; both radiating surfaces had to be located in one radiation phase plane, to sum effectively the waves generated by the half-oscillators;

• even without a directing trumpet, the radiator must provide a pronounced mono-directional radiation.