Show Engineer Reports Invention of Device to Reduce Howl I WASHINGTON WASHINGTON WASHINGTON-By By The Associated Associated Associated Press Press Elimination Elimination of the howl of a watt walt station only miles away on the same channel 1060 kilocycles has been reported to the Federal Radio commission Franklin M ar or Doolittle president of the company that operates station at New Haven Conn in a aletter aletter aletter letter to the commission describes an experiment which he says saS practically practically practically cally eliminated a a. bad heterodyne from station WAIT at Columbus Ohio Mr formerly professor processor of radio at Yale said I I rented a circuit from the telephone company between my home and the transmitting trans trans- transmitting transmitting plant at Beacon Hill the two points being about live Jive miles apart The output of the receiving set et Is connected through a step- step down transformer to the line Une At Atthe Atthe Atthe the station end the line Is con con- connected connected connected to the to-the the input of a two t stage amplifier which compensates for forthe forthe forthe the line loss As A the circuit t is en en- entirely entirely of cable the quality is de decidedly de- de decidedly decidedly bass The line lino could of course be equalized but this Is not necessary for the purpose in fact it is rather desirable to emphasize I the bass I This arrangement allows the operator at the station to hear the program as It Is being received five miles distant and If 1 a heterodyne howl is present from Coons Columbus he then adjusts until until zero beat is ob obtained ob- ob obtained This arrangement does not necessitate passing radio frequencies over the circuit but employs the audio output of the receiver Our transmitter is of the master oscillator type and we employ a crystal for checking frequency i I We have ha e had such satisfactory results with this method of reducing reducIng reducing ing Interference I am going to try tryan tryan an automatic control which will start to function as soon as the heterodyne appears The general plan of the th scheme heme 5 is to control l our transmitter tra with our crystal and to vary the frequency of the crystal costal by variation in temperature which Is controlled from the re receiving re- re receiving set at my iny home |