To Constructors

Radio Record, Volume IV, Issue 40, 17 April 1931, Page 13

To Constructors

We believe that, pending the arrival of further shipments, a scarcity of .001 semi-variable coridensers (of the Formo-densor type) exists. This is one of the components of the "Knife-edge Rejector," a highly efficient -wavetrap described in the "1931 Radio Listeners’ Guide and Callbook." For the information of readers who wish to build this wavetrap without delay, an ordinary .001 variable condenser may be substituted for the semi-variable type. The former, however, is dearer and more bulky, j i 1%