The following is from the 1943 Federal Communications Commission Annual Report to Congress:
On November 7, 1942, in further recognition of the scarcity of materials and manufacturing facilities, the Commission in cooperation with the board of War Communications, adopted Order No. 107 requiring the readjustment of broadcast transmitters inthe interest of conservation of equipment. As a result of these readjustments, radiated power was decreased by approximately 21% (one decibel) and the life of broadcast equipment (vacuum tubes in particular) has been manually prolonged without a noticable change to the broadcast listener. The licensed power of stations remains unchanged.
Radio engineers, both in the government and industry have long agreed that the change in power by one decibel could not be detected by the listener. In order to substantiate this opinion, tests were made by the Commission in cooperation with certain stations. Listeners, aware of the tests were unable to determine when the power was reduced and when it was not.
In conjunction with the above Order, there was issued a "Manual on the Adjustment of Standard Broadcast Transmitters" prepared and approved by the Board of War Communications setting forth the procedure to be followed in readjusting the equipment and in making regular checks of such adjustments.
The Commission at the same time adopted Order No. 94-A superseding its previous Order No. 94 and suspending section 3.71 of the Rules and Regulations with respect to requiring each standard broadcast stations to operate at least two-thirds of the authorized time during the broadcast day, i.e., 6 A.M. to midnight, and in lieu thereof only required operation for one-third of the broadcast day. This permitted a voluntary reduction in time of operation from 12 hours daily, in the case of an unlimited time station, to 6 hours daily. There is no restriction on the maximum hours of operation except as provided by individual licenses and the Rules and Regulations of the Commission.
Order 107-A
On August 1, 1945, Order 107-A rescinds the power reductions mandated in Order 107.
Reduced Power Table
The following is a list of various power levels and their values in dBk and what the power would be with one dB removed:
| Licensed Power | dBk | Adjusted Power during Order 107 |
|---|---|---|
| 100 watts | -10.000 dBk | 79 watts |
| 250 watts | -6.021 dBk | 198 watts |
| 500 watts | -3.011 dBk | 396 watts |
| 1,000 watts | 0.000 dBk | 794 watts |
| 2,500 watts | 3.979 dBk | 1,981 watts |
| 5,000 watts | 6.989 dBk | 3,962 watts |
| 10,000 watts | 10.000 dBk | 7,943 watts |
| 25,000 watts | 13.979 dBk | 19,815 watts |
| 50,000 watts | 16.989 dBk | 39,627 watts |
