Excerpt from Method and Apparatus Used in Testing Piezo Oscillators for Broadcasting StationsA piezo oscillator may be used in either of two ways in maintaining a station on its assigned frequency, first, it may be used for checking the frequency of the station, second, it may be used to control the frequency of the station. Tests at the bureau are usually limited to piezo oscillators intended for use in the first way mentioned because of the practical difficulties in submitting a complete piezo oscillator intended to control the frequency of the station. If the broadcasting station uses a piezo oscillator which is maintained at a constant temperature, the complete temperature-control equipment 'should be submitted with the piezo oscillator so that the test can be conducted at the desired temperature and under the conditions of use.The bureau will undertake to adjust a piezo oscillator to the frequency of a station if the frequency as received is not more than 1 per cent below that desired, but will not accept it for adjustment if the frequency is above that desired. Experience in adjusting quartz plates by grinding demonstrates that no guarantee can be made of obtaining satisfactory results. This frequency adjustment is the final step in a series of operations which are required in a technical manufacturing process. Data taken by the Bureau of Standards and other laboratories on the behavior of quartz plates as their dimen sions are changed, show that there is a small probability of obtaining a suitable frequency standard by submitting a single quartz plate for adjustment, and this type of test is not encouraged. A more satis factory type of test, both from the standpoint of the bureau and the station, is to measure the frequency of a lezo oscillator which has been completed and adjusted to frequency y the manufacturers and which operates initially in a satisfactory manner.About the PublisherForgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.comThis book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully, any imperfections that remain are intentionally left to preserve the state of such historical works.